• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Leakage current detection circuit, semiconductor apparatus, LED lighting apparatus, and vehicle The present invention relates to a leakage current detection circuit (11, 21) which detects a switch current (ii, 12, iin) that flows into a switch (105, sw1, sw2, sw3) that is addressed for leakage monitoring, and generates a detection signal (sdet) to prohibit operation of a control target circuit (12, 22, 34) which is addressed for control when the commutator current (ii, i2, iin) does not reach a predetermined threshold value.
    公开号:BR102013021176B1
    申请号:R102013021176-1
    申请日:2013-08-19
    公开日:2022-01-11
    发明作者:Koji Okamoto；Kouji Myamoto；Masaaki Nakayama；Akira Aoki；Masaharu Ando；Yosuke Tsuchiya
    申请人:Rohm Co., Ltd.；Honda Motor Co., Ltd；
    IPC主号:
    专利说明:

    BACKGROUND OF THE INVENTION Field of Invention
    [0001] The present invention relates to a leakage current detection circuit, a semiconductor apparatus that integrates the leakage current detection circuit, an LED lighting apparatus, and a vehicle. Description of Related Technique
    [0002] In recent years, when a vehicle mounted light that is mounted on a vehicle, a motorcycle and the like, an LED light that uses an LED as a light source is on its way to practical use. An LED light is excellent in energy consumption and lifespan compared to a conventional halogen light and the like.
    [0003] In an LED light like this, to keep the LED brightness constant, an LED drive circuit is required to keep an electric current flowing in the LED constant.
    [0004] As a prior art related to the above description, there is document JP-A-2011-51381.
    [0005] But, a moving body that mounts an LED light is used outdoors usually; therefore, due to external factors such as a weather condition and the like, there is a probability that an operation will switch to short circuits. Especially, on a motorcycle, switches such as a headlight and the like are next to a hand lever; therefore, there is a chance that these will get wet in the rain and produce leakage current and malfunction of the LED drive circuit. In a case where a malfunction occurs, there is a probability that, for example, the light is switched on wrongly to consume electrical energy as waste. Because of this, a mechanism is required to properly detect a leakage current. SUMMARY OF THE INVENTION
    [0006] In light of the above problems encountered by the inventors of the present application it is an object of the present invention to provide a leakage current detection circuit which is capable of detecting a leakage current properly, a semiconductor apparatus which integrates the detection circuit leakage current, an LED lighting fixture, and a vehicle.
    [0007] To achieve the above objective, a leakage current detection circuit according to the present invention detects a switch current flowing in a switch that is addressed for leakage monitoring, and generates a detection signal to prohibit operation. of a target control circuit that is addressed for control when the tap-changer current does not reach a predetermined threshold value.
    [0008] Other features, elements, steps, advantages, and features of the present invention will become more apparent from the following detailed description of preferred embodiments and the accompanying relevant drawings. BRIEF DESCRIPTION OF THE DRAWINGS
    [0009] Figure 1 is a block diagram showing a semiconductor apparatus that includes a leakage current detection circuit according to a first embodiment.
    [00010] Figure 2 is a circuit diagram showing the leakage current detection circuit according to the first embodiment.
    [00011] Figure 3 is a graph showing a relationship between a switch current, an input voltage, and a detection signal in the first mode.
    [00012] Figure 4 is a block diagram showing a semiconductor apparatus including a leakage current detection circuit according to a second embodiment.
    [00013] Figure 5 is a circuit diagram showing the leakage current detection circuit according to the second embodiment.
    [00014] Figure 6 is a graph showing a relationship between a leakage resistance, an input voltage, and a detection signal in the second mode.
    [00015] Figure 7 is a schematic view showing a vehicle that mounts an LED lighting apparatus in accordance with the present invention.
    [00016] Figure 8 is a block diagram showing an LED lighting fixture in accordance with the present invention.
    [00017] Figure 9 is a block diagram showing a semiconductor apparatus including a leakage current detection circuit according to a third embodiment.
    [00018] Figure 10 is a graph showing a relationship between a leakage resistance, an input voltage, and a detection signal in the third mode.
    [00019] Figure 11 is a time graph showing a relationship between a control signal, an input current, and a detection signal in the third mode. DETAILED DESCRIPTION OF PREFERRED MODALITIES Mode 1 LED lighting fixture
    [00020] Figure 1 is a circuit diagram showing a driver IC 10 (semiconductor apparatus) according to a first embodiment of the present invention and a structural example of an LED lighting apparatus having the driver IC 10.
    [00021] The LED lighting apparatus according to the present structural example has: a battery B1; a switch SW1; a D1 diode; a CVIN capacitor; a resistor R1; a Light Emitting Diode LED1 (load); a coil L1; a D2 diode; an N-channel type MOS field-effect transistor N1 (hereinafter called an "N1 transistor"); and driver IC 10.
    [00022] At the same time, the driver IC 10 is a monolithic semiconductor integrated circuit apparatus that integrates: a leakage current detection circuit 11; and a drive circuit 12 (target control circuit). In addition, for electrical connection to the outside, the driver IC 10 has an external terminal IN1, an external terminal SE1, an external terminal VCC1, and an external terminal OUT1.
    [00023] A way of connecting each component explained above is described. A negative terminal of battery B1 is connected to a ground terminal. A positive terminal of battery B1 is connected to a first terminal of switch SW1. A second terminal of switch SW1 is connected to an anode of diode D1. A cathode of diode D1 is connected to a first terminal of resistor R1.
    [00024] A first terminal of the CVIN capacitor is connected to the ground terminal. A second terminal of capacitor CVIN is connected to a connection node between the cathode of diode D1 and the first terminal of resistor R1. A second terminal of resistor R1 is connected to an anode of Light Emitting Diode LED1. A cathode of Light Emitting Diode LED1 is connected to a first terminal of coil L1. A second terminal of coil L1 is connected to a drain of transistor N1.
    [00025] An anode of diode D2 is connected to a connection node between the second terminal of coil L1 and the drain of transistor N1. A cathode of diode D2 is connected to the connection node between the cathode of diode D1 and the first terminal of resistor R1. A gate of transistor N1 is connected to the external terminal OUT1. A source from transistor N1 is connected to the ground terminal.
    [00026] The external terminal IN1 is connected to the connection node between the cathode of diode D1 and the first terminal of resistor R1. In addition, the external terminal IN1 is connected to the leakage current detection circuit 11 and the driving circuit 12 to the driver IC 10. The external terminal SE1 is connected to a connection node between the second terminal of resistor R1 and the anode. of Light Emitting Diode LED1. Also, external terminal SE1 is connected to trigger circuit 12 on trigger IC 10. External terminal VCC1 is connected to a connection node between a second terminal of switch SW1 and the anode of diode D1.
    [00027] Leakage current detection circuit 11 is connected to drive circuit 12. In addition, leakage current detection circuit 11 has a signal path to provide a Sdet detection signal to drive circuit 12 Trigger circuit 12 is connected to external terminal IN1 and external terminal OUT1.
    [00028] Next, the operation of the LED lighting fixture having the above structure is described in detail. At the same time, in the following description, a voltage appearing at a connection node between the second terminal of switch SW1 and the anode of diode D1 is indicated by VCC, a voltage appearing at the connection node between the cathode of diode D1 and the first terminal of resistor R1 is indicated by VIN, and a voltage appearing at a connection node between the second terminal of resistor R1 and the anode of Light Emitting Diode LED1 is indicated by VSE; in this way, each node voltage is indicated by a reference symbol.
    [00029] First, the operation with switch SW1 kept in an activated state is described. In a case where switch SW1 is turned on, the electrical power supply is started by battery B1, and soon the VIN voltage becomes greater than a voltage that enables the operation of the drive circuit 12. The drive circuit 12 receiving the supplying the VIN voltage generates a potential difference, which is greater than a threshold voltage of transistor N1, between the source and gate of transistor N1.
    [00030] As a result of this, transistor N1 is turned on, whereby the source and drain of transistor N1 are short-circuited with each other. Consequently, Light Emitting Diode LED1 emits light through an electric current flowing through diode D1 and resistor R1. Furthermore, to keep the electrical current flowing in the Light Emitting Diode LED1 constant, the drive circuit 12 performs on/off control of transistor N1 according to a change in the VSE voltage. In this way, an amount of light emitting from the Light Emitting Diode LED1 is kept constant.
    [00031] In the above state, if switch SW1 is turned off, the electric current flows back through coil L1 and diode D2, and gradually decreases. As a result of this, the light emission of the Light Emitting Diode LED1 stops.
    [00032] The operation on driver IC 10 is described below.
    [00033] Leakage current detection circuit 11 monitors the input voltage VIN of external terminal IN1. And, in a case where the VIN voltage is greater than a predetermined voltage threshold value, the leakage current detection circuit 11 instructs the drive circuit 12 to perform light emission and controls the dimming of the Light Emitting Diode. LED1. Furthermore, in a case where the VIN voltage is not greater than the predetermined voltage threshold value, the leakage current detection circuit 11 instructs the drive circuit 12 not to perform light emission and controls the dimming of the Diode. LED Light Emitter1.
    [00034] More specifically, the leakage current detection circuit 11 changes a logic level of the detection signal Sdet to be supplied to the drive circuit 12 according to a voltage magnitude VIN. At the same time, the above voltage threshold value is decided in advance based on the voltage that enables the operation of the drive circuit 12. For example, in a case where the voltage that enables the operation is 6 V, a voltage slightly lower than this voltage is decided as the voltage threshold value.
    [00035] Figure 3 is a schematic view to describe an example of operation of the leakage current detection circuit 11 according to the present invention. Figure 3(a) shows a relationship between an electrical current IIN (switch current) flowing into the leakage current detection circuit 11 and the voltage VIN (input voltage). Figure 3(b) shows a relationship between the VIN voltage and the Sdet detection signal.
    [00036] The vertical axis of Figure 3 (a) indicates the magnitude of the electric current IIN, while the horizontal axis indicates the magnitude of the voltage VIN. The vertical axis of Figure 3(b) indicates the logic level of the Sdet detection signal, while the horizontal axis indicates the magnitude of the voltage VIN.
    [00037] At the same time, Vth1 of Figure 3(a) is a threshold voltage of a transistor N13 (described later) included in leakage current detection circuit 11. Also, Vth2 corresponds to the threshold voltage value above. Vst is a minor voltage threshold that enables the drive circuit 12 to operate.
    [00038] In the present embodiment, as shown in Figure 3(b), at a point in time where the VIN voltage exceeds the Vth2 voltage threshold value, the detection signal Sdet changes from Low to High. The drive circuit 12 decides whether or not to control transistor N1 according to the High/Low state of the Sdet detection signal.
    [00039] Also, in a case where the voltage VIN does not exceed the threshold voltage value Vth2, the leakage current detection circuit 11 considers the electrical current IIN flowing into the leakage current detection circuit 11 as a leakage current and operates to absorb the leakage current. In the following, details of the trigger IC 10 for performing the above detection and absorption operations are described. IC trigger
    [00040] Figure 2 is a circuit diagram showing a circuit structure of driver IC 10 in accordance with a first embodiment of the present invention. At the same time, in Figure 2, a structure of an apparatus connected externally to the driver IC 10 is the same as in Figure 1; therefore, the description is skipped here.
    [00041] The driver IC 10 according to the present structural example has: the leakage current detection circuit 11; the drive circuit 12; a reference power supply 13; a constant current generating circuit 14; a hysteresis voltage generating circuit 15; and a logic circuit 16.
    [00042] The leakage current detection circuit 11 has: an N-channel type MOS field effect transistor N13 (hereinafter called a "N13 transistor"); an N14 N-channel type MOS field effect transistor (hereinafter called an "N14 transistor"); resistors R14 to R16; and a resistor R19. Trigger circuit 12 has: a CMP1 comparator; an INV1 inverter; and an INV2 inverter.
    [00043] The constant current generation circuit 14 has: an operational amplifier OPA1; a resistor R13; a resistor R17; a resistor R18; and an N-channel type MOS field effect transistor N12 (hereinafter called an "N12 transistor"). The hysteresis voltage generating circuit 15 has: a resistor R11; a resistor R12; and a P channel type MOS field effect transistor P11 (hereinafter called a "transistor P11").
    [00044] A way of connecting each component explained above is described. First, describing the reference power supply 13 and the constant current generating circuit 14, an input terminal of the reference power supply 13 is connected to the external terminal VCC1. A first terminal of resistor R17 is connected to an output terminal of reference power supply 13. A second terminal of resistor R17 is connected to a first terminal of resistor R18. A second terminal of resistor R18 is connected to the ground terminal.
    [00045] A non-inverting input terminal of the operational amplifier OPA1 is connected to a connection node between the second terminal of resistor R17 and the first terminal of resistor R18. An inverting input terminal of the operational amplifier OPA1 is connected to a connection node between a source of transistor N12 and a first terminal of resistor R13. An output terminal of the operational amplifier OPA1 is connected to a gate of transistor N12. A second terminal of resistor R13 is connected to the ground terminal. A drain of transistor N12 is connected to a second terminal of resistor R12.
    [00046] Next, describing the hysteresis voltage generation circuit 15, a first terminal of resistor R12 is connected to a second terminal of resistor R11. A first terminal of resistor R11 is connected to the external terminal IN1.
    [00047] A source of transistor P11 is connected to a connection node between the second terminal of resistor R11 and the first terminal of resistor R12. A drain of transistor P11 is connected to a connection node between the first terminal of resistor R11 and the external terminal IN1. A gate of transistor P11 is connected to a connection node between an output terminal of inverter INV2 and a first input terminal of logic circuit 16.
    [00048] Next, describing drive circuit 12, a non-inverting input terminal of comparator CMP1 is connected to external terminal SE1. An inverting input terminal of the comparator CMP1 is connected to a connection node between the second terminal of resistor R12 and the drain of transistor N12. An output terminal of comparator CMP1 is connected to the first input terminal of logic circuit 16 through inverter INV1 and inverter INV2.
    [00049] The following describes the leakage current detection circuit 11, a first terminal of resistor R14 (second resistor), a first terminal of resistor R15 (third resistor), and a first terminal of resistor R19 (first resistor) are connected to a connection node between the external terminal IN1 and resistor R11.
    [00050] A second terminal of resistor R19 is connected to a drain of transistor N13 (first transistor). A second terminal of resistor R14 is connected to a drain of transistor N14 (second transistor). A source of transistor N13 is connected to the ground terminal. A gate of transistor N13 is connected to a connection node between the second terminal of resistor R14 and the drain of transistor N14.
    [00051] A source of transistor N14 is connected to the ground terminal. A gate of transistor N14 is connected to a connection node between a second terminal of resistor R15 and a first terminal of resistor R16 (fourth resistor). A second terminal of resistor R16 is connected to the ground terminal.
    [00052] Describing logic circuit 16, a second input terminal of logic circuit 16 is connected to a connection node between the second terminal of resistor R19 and the drain of transistor N13. An output terminal of logic circuit 16 is connected to the external terminal OUT1.
    [00053] Next, the operation of the trigger IC 10 that has the above structure is described in detail. At the same time, in the following description, a voltage generated by the reference power supply 13 is indicated by V1, a voltage that appears at the connection node between the drain of transistor N12 and the first terminal of resistor R13 is indicated by V2, and a voltage appearing at a connection node between the source of transistor N12 and the second terminal of resistor R12 is indicated by V3; in this way, each node voltage is indicated by a reference symbol.
    [00054] First, the operations of reference power supply 13 and constant current generating circuit 14 are described. Reference power supply 13 generates voltage V1 (eg 5 V), i.e. a constant voltage , of the mutable voltage VCC, and supplies the voltage for the constant current generating circuit 14.
    [00055] The constant current generating circuit 14 uses the voltage V1 to make the hysteresis voltage generating circuit 15 generate an electrical current I1 which is a constant current. More specifically, the operational amplifier OPA1 included in the constant current generation circuit 14 performs on-off control of the transistor N12 connected to the output terminal so that a voltage applied to the non-inverting input terminal and a voltage applied to the input terminal inverter become equal to each other. In this way, the voltage V2 is kept constant (eg 6 V), and the electrical current I1 becomes a constant current (eg 6 mA).
    [00056] The operation of the drive circuit 12 is described below. The drive circuit 12 is an electric current control circuit that keeps the electric current flowing in the Light Emitting Diode LED1 constant. More specifically, the drive circuit 12 decides the High/Low state of a control signal S0 according to voltage VSE and voltage V3.
    [00057] Voltage V3 is applied to an inverting input terminal of comparator CMP1. The VSE voltage is applied to a non-inverting input terminal of the CMP1 comparator. The CMP1 comparator compares the two voltages with each other for the supplied control signal S0. The control signal S0 goes High in a case where voltage VSE is greater than voltage V3, and goes Low in a case where voltage VSE is less than voltage V3. Accordingly, in a case where the VSE voltage rises to a predetermined voltage, transistor N1 is turned on, and in a case where the VSE voltage falls to a predetermined voltage, transistor N1 is turned off.
    [00058] The operation of the hysteresis voltage generation circuit 15 is described below. The control signal S0 described above is input to the gate of transistor P11 of the hysteresis voltage generation circuit 15. In a case where the control signal S0 is Low, transistor P11 is turned on. Accordingly, an electric current flows in transistor P11 which has a resistance value smaller than resistor R11; therefore, the voltage V3 rises.
    [00059] On the other hand, in a case where the control signal S0 is High, transistor P11 is turned off, and an electrical current flows in resistor R11. Accordingly, the voltage V3 decreases compared to the activated state. As described above, the hysteresis voltage generating circuit 15 turns transistor P11 on/off according to the change in voltage VSE to control voltage V3. By repeating this, the amount of light emitting from the Light Emitting Diode LED1 is kept constant.
    [00060] The operation of the leakage current detection circuit 11 is described below. The leakage current detection circuit 11 causes the electrical current IIN to flow to the earth terminal in a case where the VIN voltage does not exceed the voltage threshold value Vth2, and makes the detection signal Sdet go Low. The leakage current detection circuit 11 makes the detection signal Sdet go High in a case where the VIN voltage exceeds the voltage threshold value Vth2. Here, the value of the voltage threshold value Vth2 is suitably variable according to an upper limit (Ith) of a leakage current to be absorbed.
    [00061] For example, an escape route is assumed to occur due to an influence of rain and the like irrespective of an off state of switch SW1. In this case, electrical charges are stored inside the CVIN capacitor by a leakage current, and the VIN voltage rises.
    [00062] As a result of this, in the leakage current detection circuit 11 for detecting the VIN voltage, a voltage is applied to the gate of transistor N13. At the same time, at this time, there is also a voltage applied to the gate of transistor N14; but, the voltage is adjusted to become minuscule by dividing the voltage resistance by resistor R15 and resistor R16.
    [00063] If the VIN voltage keeps rising, a potential difference greater than the threshold voltage (Vth1 of Figure 3) of transistor N13 occurs between the source and gate of transistor N13, so transistor N13 is turned on. In this way, electrical current IIN flows in resistor R19 and transistor N13. In other words, the leakage current is discharged to the earth terminal through transistor N13.
    [00064] Here, if leakage does not occur and switch SW1 is short-circuited by user operation, the VIN voltage keeps going up further. In this case, a potential difference greater than a threshold voltage of transistor N14 occurs between the source and gate of transistor N14, whereby transistor N14 is turned on. In this way, electrical current IIN flows in resistor R14 and transistor N14.
    [00065] As a result of this, the potential difference between the source and the gate of transistor N13 becomes less than the threshold voltage of transistor N13, whereby transistor N13 is turned off. In other words, the route, through which the electrical current IIN is discharged to the ground terminal through transistor N13, is turned off. And, if the VIN voltage reaches the voltage that enables the operation of the drive circuit 12, it becomes possible to carry out the light emission and control the dimming of the Light Emitting Diode LED1.
    [00066] At the same time, to perform the above operation, such as resistors R14 to R16, resistors that have a resistance value greater than resistor R19 are used. Due to this, as shown in Figure 3, in a state where the voltage VIN exceeds the threshold voltage value Vth2, i.e., in a state where the electric current IIN flows in resistors R14 to R16, the rise of the electric current IIN becomes becomes moderate.
    [00067] From the above operation, a threshold voltage (Vth2 of Figure 3) of the leakage current detection circuit 11 is decided by the following calculation formula. At the same time, the following RON indicates an on value of resistance of transistor N13. Vth2 = (R19 + RON) x IIN x R16 / (R15 + R16)
    [00068] The operation of logic circuit 16 is described below. In a case where the Sdet detection signal input from the leakage current detection circuit 11 is Low, that is, in a case where the VIN voltage does not reach the voltage threshold value Vth2, even if control signal S0 is input from drive circuit 12, logic circuit 16 invalidates control signal S0 (always Low). In this way, the Light Emitting Diode LED1 is prevented from being erroneously turned on by the leakage current.
    [00069] Also, in a case where the detection signal Sdet input from the leakage current detection circuit 11 is High, i.e., in a case where the VIN voltage reaches the voltage threshold value Vth2, if the control S0 is input to drive circuit 12, logic circuit 16 supplies the control signal S0 as a control signal S1 to the external terminal OUT1. Accordingly, in a case where the VIN voltage reaches the voltage that enables the operation, it becomes possible to realize the light emission and control the dimming of the Light Emitting Diode LED1.
    [00070] According to the above-described leakage current detection circuit 11 in the present embodiment, in a state where the VIN voltage does not reach the voltage that enables the drive circuit 12 to operate and the electrical current IIN is inferable as a leakage current, it is possible to discharge the electric current IIN. In addition, it is possible to prohibit the operation of the drive circuit 12 and prevent the Light Emitting Diode LED1 from being turned on erroneously. Mode 2
    [00071] In mode 1 described above, it is possible to detect a leakage current and absorb it; but in a case where the leakage current occurs for a long time, there is a probability that a large amount of electrical energy will be consumed and the battery will be depleted. Furthermore, there is a probability that inequality between the voltage threshold values occurs due to a difference between the individual connected resistors of the respective transistors. Accordingly, a second embodiment of the present invention employs the following structure. LED lighting fixture
    [00072] Figure 4 is a circuit diagram showing a driver IC 20 (semiconductor apparatus) according to the second embodiment of the present invention and a structural example of an LED lighting apparatus that includes the driver IC 20.
    [00073] The LED lighting apparatus according to the present structural example has: a battery B2; the driver IC 20; an N-channel type MOS field-effect transistor N2 (hereinafter called an "N2 transistor"); a Light Emitting Diode LED2 (load); and a switch SW2.
    [00074] At the same time, the driver IC 20 is a monolithic semiconductor integrated circuit apparatus that integrates: a leakage current detection circuit 21; a drive circuit 22 (target control circuit); and a constant voltage source 23. In addition, to realize electrical connection with the outside, the driver IC 10 has an external terminal IN2, an external terminal SE2, and an external terminal OUT2.
    [00075] External terminal IN2 is an input terminal for voltage VIN. External terminal SE2 is a connection terminal for switch SW2. The external terminal OUT2 is an output terminal for a control signal S2.
    [00076] A way of connecting each component explained above is described. A negative battery terminal B2 is connected to the ground terminal. A positive terminal of battery B2 is connected to a drain of transistor N2. A source of transistor N2 is connected to an anode of Light Emitting Diode LED2. A gate of transistor N2 is connected to the external terminal OUT2. A cathode of Light Emitting Diode LED2 is connected to the ground terminal.
    [00077] The external terminal IN2 is connected to a connection node between the positive terminal of battery B2 and the drain of transistor N2. External terminal SE2 is connected to a second terminal of switch SW2. A first terminal of switch SW2 is connected to the earth terminal.
    [00078] On driver IC 20, constant voltage source 23 is connected to external terminal IN2 and leakage current detection circuit 21. Leakage current detection circuit 21 is connected to external terminal SE2. Furthermore, the leakage current detection circuit 21 has a signal path to supply the detection signal Sdet to the drive circuit 22. The drive circuit 22 is connected to the external terminal IN2, to the constant voltage source 23, and to the OUT2 external terminal.
    [00079] Next, the operation of the LED lighting fixture having the above structure is described in detail. At the same time, in the following description, a voltage applied to the external terminal IN2 is indicated by VIN, a voltage applied to the external terminal SE2 is indicated by V4 (input voltage), and a voltage generated by the constant voltage source 23 is indicated. by VREG; in this way, each node voltage is indicated by a reference symbol.
    [00080] First, operation with switch SW2 kept in an activated state is described. In a case where switch SW2 is on, the leakage current detection circuit 21 brings the detection signal Sdet Down by operation described later. The drive circuit 22 receiving the Sdet detection signal generates a potential difference, which is greater than a threshold voltage of transistor N2, between the source and gate of transistor N2.
    [00081] As a result of this, transistor N2 is turned on, whereby the source and drain of transistor N2 are short-circuited with each other. Consequently, the Light Emitting Diode LED2 emits light through an electrical current flowing through transistor N2.
    [00082] At the same time, although not shown in Figure 4, in a case where constant current control of Light Emitting Diode LED2 is performed, a resistor corresponding to resistor R1 in Figure 2 is externally connected to driver IC 20, and the same constant current control as in the description above is performed by the drive circuit 22. In this way, a light emitting amount of the Light Emitting Diode LED2 is kept constant.
    [00083] On the other hand, if switch SW2 is off, the leakage current detection circuit 21 brings the detection signal Sdet to High via the operation described later. The drive circuit 22 receiving the Sdet detection signal turns off transistor N2. As a result of this, the light emission of the Light Emitting Diode LED2 is stopped.
    [00084] The operation on driver IC 20 is described below.
    [00085] Constant voltage source 23 generates voltage VREG (e.g. 5 V), i.e. a constant voltage, from mutable voltage VIN, and supplies the voltage to leakage current detection circuit 21.
    [00086] Leakage current detection circuit 21 monitors voltage V4 which changes depending on the on/off state of switch SW2 and a leak. and, in a case where the voltage V4 is less than a predetermined voltage threshold value, the leakage current detection circuit 21 instructs the drive circuit 22 to perform light emission and controls the dimming of the Light Emitting Diode LED2. Furthermore, in a case where the voltage V4 is greater than the predetermined voltage threshold value, the leakage current detection circuit 21 instructs the drive circuit 22 not to emit light and controls the dimming of the Emitting Diode. of LED Light2.
    [00087] More specifically, the leakage current detection circuit 21 changes the logic level of the detection signal Sdet to be supplied to the drive circuit 22 according to a voltage magnitude V4. At the same time, the above voltage threshold value is decided in advance based on a resistance value RSW of a leakage resistor occurring in a leakage path of switch SW2.
    [00088] The following details the leakage current detection circuit 21 to perform the above detection operation. Leakage current detection circuit
    [00089] Figure 5 is a circuit diagram showing a circuit structure of the leakage current detection circuit 21 according to the second embodiment of the present invention. At the same time, in Figure 5, a structure of an apparatus connected externally to the current sensing circuit 21 is the same as in Figure 4; therefore, the description is skipped here. Furthermore, as for details of the drive circuit 22, it is possible to use the same structure as the drive circuit 12 of mode 1; therefore, the description is skipped here.
    [00090] The leakage current detection circuit 21 according to the present structural example has: a constant current source CS1; a CMP2 comparator; and a constant voltage source B3.
    [00091] A way of connecting each component explained above is described. An input terminal of the constant current source CS1 is connected to an application terminal for voltage VREG. An output terminal of the constant current source CS1 is connected to the external terminal SE2.
    [00092] A non-inverting input terminal of the CMP2 comparator is connected to a connection node between the output terminal of the constant current source CS1 and the external terminal SE2. An inverting input terminal of the CMP2 comparator is connected to a positive terminal of the constant voltage source B3. A negative terminal of constant voltage source B3 is connected to the ground terminal. An output terminal of the CMP2 comparator is connected, as an output terminal for the detection signal Sdet, to the drive circuit 22.
    [00093] The operation of the leakage current detection circuit 21 having the above structure is described in detail below. At the same time, in the following description, a voltage appearing at the connection node between the output terminal of the constant current source CS1 and the external terminal SE1 is indicated by V4, and a voltage generated by the constant voltage source B3 is indicated by by Vth3; in this way, each node voltage is indicated by a reference symbol.
    [00094] Constant current source CS1 uses voltage VREG to generate an electrical current I2 (switch current) which is a constant current. Electrical current I2 is supplied from the output terminal of the constant current source CS1 through the external terminal SE2. In this way, voltage V4 occurs at external terminal SE2 according to the on/off state of switch SW2 and a leakage.
    [00095] The constant voltage source B3 generates a threshold voltage value Vth3, ie a constant voltage, at its positive terminal. At the same time, a threshold voltage value Vth3 value is a value obtained by multiplying a threshold resistance value Rth (threshold value for determining whether the switch SW2 is short-circuited or not) by the electrical current I2. For example, in a case where the threshold resistance value Rth is 20 Q and the electrical current I2 is 1 mA, the threshold voltage value Vth3 becomes 20 mV.
    [00096] The voltage threshold above Vth3 is applied to the inverting input terminal of the CMP2 comparator. Voltage V4 is applied to the non-inverting input terminal of the CMP2 comparator. The CMP2 comparator compares the two voltages with each other to change the logic level of the Sdet detection signal.
    [00097] Figure 6 is a schematic view to describe an example of operation of the leakage current detection circuit 21 according to the present invention. Figure 6 shows a relationship between the leakage resistance value RSW (upper stage), voltage V4 (middle stage), and detection signal Sdet (lower stage). The detection signal Sdet goes High in a case where the voltage V4 is greater than the threshold voltage Vth3, and goes Low in a case where the voltage V4 is less than the threshold voltage Vth3.
    [00098] As shown in Figure 6, in a case where the leakage resistance value RSW is less than the threshold resistance value Rth and consequently the voltage V4 is less than the threshold voltage value Vth3, the detection signal Sdet is brought down. On the other hand, in a case where the leakage resistance value RSW is greater than the threshold resistance value Rth and consequently the voltage V4 is greater than the threshold voltage value Vth3, the detection signal Sdet is brought to High . The drive circuit 22 decides according to the High/Low state of the Sdet detection signal whether to emit light and controls the dimming of the Light Emitting Diode LED2 or not.
    [00099] In a case where the detection signal Sdet is High, the drive circuit 22 receiving the detection signal for emitting light and controlling the dimming of the Light Emitting Diode LED2. In a case where the detection signal Sdet is Low, the drive circuit 22 receiving the detection signal performs the light emission and controls the dimming of the Light Emitting Diode LED2.
    [000100] Summarizing the above description, there are three patterns to follow according to the state of switch SW2. (A) State where switch SW2 is open and no leakage occurs
    [000101] Both the switch SW2 and the leakage resistance value RSW have a high impedance. Consequently, the Sdet detection signal goes High; therefore, the drive circuit 12 does not operate. (B) State where switch SW2 is open and leakage occurs
    [000102] Switch SW2 has a high impedance, however the leakage resistance has a low impedance. But, the leakage resistance value RSW is equal to or greater than the threshold resistance value Rth; therefore, the Sdet detection signal goes High, and drive circuit 12 does not operate. (C) State where switch SW2 is short-circuited
    [000103] Switch SW2 has a low impedance (less than the threshold resistance value Rth); therefore, regardless of a leak, the detection signal Sdet goes Low, and drive circuit 12 operates.
    [000104] According to the leakage current detection circuit 21 of the present embodiment described above, even if the voltage V4 decreases, a leakage is considered to be occurring in switch SW2 until the voltage V4 becomes less than the value voltage limit Vth3. In other words, switch SW2 is considered not short-circuited by the user. Due to this, in the above state (B), it is possible to prohibit the operation of the drive circuit 22 and prevent the Light Emitting Diode LED2 from being turned on erroneously.
    [000105] Furthermore, in the present embodiment, the structure is employed so that the leakage current detection circuit 21 does not draw a leakage current from battery B2, but only monitors the on/off state of switch SW2 and a escape. Due to this, if the electrical current I2 is determined to be small enough, even if a leakage occurs in the switch SW2, it is possible to avoid a situation where the leakage current flows into the leakage current detection circuit 11 in large amounts. and battery B2 is exhausted. lighting device
    [000106] Figure 7 is an appearance view showing an appearance of a motorcycle (vehicle) that mounts the LED lighting fixture according to the second embodiment. Figure 8 is a block diagram showing a structural example of the driver IC 20 according to the second embodiment connected to a plurality of switches and lights.
    [000107] The LED lighting apparatus according to the present structural example has: the driver IC 20; a beacon 101; a tail light 102; a flashing light 103; a flashing light 104; and a switch 105. At the same time, the switch 105 includes: a flashing switch 105a; a beacon switch 105b; and a 105c lantern/brake switch.
    [000108] From the headlight 101 to the turn signal light 104 each has inside the Light Emitting Diode LED2 shown in Figure 4. In addition, from the above turn signal switch 105a to the flashlight/brake switch 105c each has inside switch SW2 shown in Figure 4.
    [000109] The driver IC 20 according to the present structural example has a plurality of leakage current sensing circuits 21 and a plurality of driver circuits 22. As shown in Figure 8, an assembly of the leakage current sensing circuit leakage 21 and drive circuit 22 are arranged for a switch and light assembly. For example, a leakage current detection circuit 21b and a driving circuit 22b are arranged for the beacon switch 105b and the beacon 101. Accordingly, it is possible to detect a leakage current in each switch, and carry out control activation of a light that corresponds to each switch according to the detection result. Mode 3
    [000110] In embodiment 2 described above, there is a problem that in a case where an oxide layer is formed on a surface of switch SW2 due to time dependent change and the like, it is difficult to remove the oxide layer. If an oxide layer is formed on switch SW2, the resistance value of switch SW2 goes up in an on time; therefore, it is desirable to remove the oxide layer. But in the switch SW2, the electrical current I2 flowing in on-time is just a tiny current of a few milliamps to tens of milliamps; therefore, it is impossible to remove the oxide layer by means of a high current. Accordingly, a third embodiment of the present invention employs the following structure. LED lighting fixture
    [000111] Figure 9 is a circuit diagram showing a driver IC 30 (semiconductor apparatus) according to the third embodiment of the present invention and a structural example of an LED lighting apparatus having the driver IC 30.
    [000112] The LED lighting apparatus according to the present structural example has: a battery B4; a switch SW3; an RTHSET resistor; the driver IC 30; a P3 channel P-type MOS field effect transistor (hereinafter called a "P3 transistor"); a Light Emitting Diode LED3 (load); and an RSINKSET resistor.
    [000113] At the same time, the driver IC 30 is a monolithic semiconductor integrated circuit apparatus that integrates: a CR 31 timer; a current mirror circuit 32; a logic circuit 33; a drive circuit 34 (target control circuit); a CMP3 comparator; an OPA2 operational amplifier; a constant voltage source B5; and an N-channel type MOS field effect transistor N31 (hereinafter called a "N31 transistor"). In addition, for electrical connection to the outside, the driver IC 30 has an external terminal IN3, an external terminal STIN, an external terminal THSET, an external terminal OUT3, and an external terminal SINKSET.
    [000114] External terminal IN3 is an input terminal for voltage VIN. The external terminal STIN is a connection terminal for switch SW3. The external terminal THSET is a connection terminal for the resistor RTHSET. The external terminal OUT3 is an output terminal for a control signal S4. The external terminal SINKSET is a connection terminal for the resistor RSINKSET.
    [000115] A way of connecting each component explained above is described. A negative battery terminal B4 is connected to the ground terminal. A positive battery terminal B4 is connected to the external terminal IN3, a first terminal of switch SW3, and a first terminal of resistor RTHSET. A second terminal of switch SW3 is connected to the external terminal STIN. A second terminal of resistor RTHSET is connected to the external terminal THSET.
    [000116] A source of transistor P3 is connected to a connection node between the second terminal of switch SW3 and the external terminal STIN. A drain of transistor P3 is connected to an anode of Light Emitting Diode LED3. A gate of transistor P3 is connected to the external terminal OUT3. A cathode of Light Emitting Diode LED3 is connected to the ground terminal.
    [000117] A first terminal of resistor RSINKSET is connected to the external terminal SINKSET. A second terminal of the RSINKSET resistor is connected to the ground terminal.
    [000118] The following describes a way of connecting each component to the driver IC 30. A first terminal of the CR 31 timer is connected to a first terminal of the current mirror circuit 32. A second terminal of the CR 31 timer is connected. to a first terminal of logic circuit 33.
    [000119] A second terminal of current mirror circuit 32 is connected to the external terminal STIN. A third terminal of the current mirror circuit 32 is connected to the external terminal THSET. A fourth terminal of current mirror circuit 32 is connected to a drain of transistor N31.
    [000120] A source of transistor N31 is connected to the external terminal SINKSET. A gate of transistor N31 is connected to an output terminal of the operational amplifier OPA2. A non-inverting input terminal of the operational amplifier OPA2 is connected to a positive terminal of the constant voltage source B5. An inverting input terminal of the OPA2 operational amplifier is connected to a connection node between the source of transistor N31 and the external terminal SINKSET. A negative terminal of the constant voltage source B5 is connected to the ground terminal.
    [000121] A non-inverting input terminal of the CMP3 comparator is connected to a connection node between the external terminal STIN and the second terminal of the current mirror circuit 32. An inverting input terminal of the CMP3 comparator is connected to a node of connection between the external terminal THSET and the third terminal of the current mirror circuit 32. An output terminal of the comparator CMP3 is connected, as an output terminal for the detection signal Sdet, to a second terminal of the logic circuit 33.
    [000122] An output terminal of logic circuit 33 is connected, as an output terminal for a control signal S3, to drive circuit 34. An output terminal of drive circuit 34 is connected, as an output terminal to a control signal S4, to the external terminal OUT3.
    [000123] Next, the operation of the LED lighting fixture having the above structure is described in detail. At the same time, in the following description, a voltage applied to the external terminal IN3 is indicated by VIN, a voltage that appears at the connection node between the source of transistor N31 and the external terminal SINKSET is indicated by V5, a voltage that appears at the connection node between the external terminal STIN and the second input terminal of the current mirror circuit 32 is indicated by V6, and a voltage appearing at the connection node between the external terminal THSET and the third input terminal of the mirror circuit of current 32 is indicated by Vth4; in this way, each node voltage is indicated by a reference number.
    [000124] First, the operation on driver IC 30 is described. Constant voltage source B5 generates a constant voltage (eg 1 V) and applies the voltage to the non-inverting input terminal of the operational amplifier OPA2. The OPA2 operational amplifier performs on-off control of transistor N31 connected to the output terminal so that the voltage applied to the non-inverting input terminal and the voltage applied to the inverting input terminal become equal to each other. In this way, the voltage V5 is kept constant, and the electrical current ISINKSET becomes a constant current.
    [000125] Timer CR 31 provides a control signal S5, i.e. a PWM signal, to current mirror circuit 32. In addition, timer CR 31 provides a control signal S6, i.e. a PWM signal , for logic circuit 33. At the same time, the control signal S5 and the control signal S6 are equal to each other.
    [000126] The control signal S5 is used in order for the current mirror circuit 32 to decide a timing to draw an IDET electric current and an ITHSET electric current. Control signal S6 is used in order for logic circuit 33 to decide a timing to perform a High/Low switching of control signal S3 (details are described later).
    [000127] The current mirror circuit 32 uses an electrical current ISINKSET generated by the operational amplifier OPA2 to generate electrical current IDET and electrical current ITHSET which are a constant current. At the same time, the operation of the current mirror circuit 32 is performed only in a case where the control signal S5 input from the timer CR 31 is High and not performed in a case where the control signal S5 is Low.
    [000128] The voltage V6 decided by the IDET electric current and the value of the leakage resistance RSW is applied to the non-inverting input terminal of the CMP3 comparator. The threshold voltage value Vth4 decided by the electrical current ITHSET and the resistance value of resistor RTHSET is applied to the inverting input terminal of the CMP3 comparator. The CMP3 comparator compares the two voltages with each other to change the logic level of the Sdet detection signal.
    [000129] Figure 10 is a schematic view to describe an example of operation of the CMP3 comparator according to the present invention. Figure 10 shows a relationship between the value of leakage resistance RSW (upper stage), voltage V6 (middle stage), and detection signal Sdet (lower stage). The detection signal Sdet goes High in a case where the voltage V6 is greater than the threshold voltage Vth4, and goes Low in a case where the voltage V6 is less than the threshold voltage Vth4.
    [000130] As shown in Figure 10, in a case where the leakage resistance value RSW is greater than the threshold resistance value Rth and consequently the voltage V6 is lower than the threshold voltage value Vth4, the detection signal Sdet is brought down. On the other hand, in a case where the leakage resistance value RSW is lower than the threshold resistance value Rth and consequently the voltage V6 is higher than the threshold voltage value Vth4, the detection signal Sdet is brought to High . Logic circuit 33 decides the High / Low state of the control signal S3 according to the High / Low state of the detection signal Sdet.
    [000131] In a case where the detection signal Sdet is High, the logic circuit 33 receiving the detection signal Sdet brings the control signal S3 to Low. In a case where the control signal S3 is Low, the drive circuit 34 receiving the control signal S3 brings the control signal S4 to Low. As a result of this, transistor P3 is turned on, whereby an electric current ILED flows in Light Emitting Diode LED3.
    [000132] On the other hand, in a case where the detection signal Sdet is Low, the logic circuit 33 receiving the detection signal Sdet brings the control signal S3 to High. In a case where the control signal S3 is High, the drive circuit 34 receiving the control signal S3 brings the control signal S4 to High. As a result of this, transistor P3 is turned off, so the electrical current ILED does not flow into the Light Emitting Diode LED3.
    [000133] At the same time, although not shown in Figure 9, in a case where constant current control of Light Emitting Diode LED3 is performed, a resistor corresponding to resistor R1 in Figure 2 is externally connected to driver IC 30, and the same constant current control as described above is performed by the drive circuit 34. In this way, a light emitting amount of the Light Emitting Diode LED3 is kept constant.
    [000134] The following describes a relationship between various electrical signals and currents in the respective states, where the switch SW3 is in an off state (including a leak being present/leakage not being present) and where the switch SW3 is in an off state. activated state, using Figure 11. Figure 11 is a time graph showing a relationship between control signal S5 and control signal S6 (first stage), IDET electrical current, and ITHSET electrical current (second stage) flowing in the current mirror circuit 32, the detection signal Sdet (third stage), and the control signal S3 (fourth stage).
    [000135] At the same time, dashed lines at t1 to t5 indicate times when the High/Low state of control signal S5 and control signal S6 change. Control signal S5 and control signal S6 change in a constant period. In the example of Figure 11, t1 to t3 is a first period, and t3 to t5 is a second period. In the present embodiment, as an example, the description is performed assuming that the switch SW3 is off at t1; and switch SW3 is connected to t3.
    [000136] First, at t1, when the control signal S5 and the control signal S6 change from Low to High, the current mirror circuit 32 starts pulling the IDET electric current and the ITHSET electric current. Also, logic current 33 decides the High/Low state of the control signal S3. In the present example, because SW3 is off at time point t1, the detection signal Sdet goes Low; consequently, the control signal S3 goes High.
    [000137] Next, at t2, when the control signal S5 and the control signal S6 change from High to Low, the current mirror circuit 32 pulls the electrical current IDET and electrical current ITHSET. Also, regardless of the High/Low state of the Sdet detection signal, logic circuit 33 operates as a latch circuit that maintains the High/Low state of the control signal S3 at time point t1. In the present example, High is held at time point t2. At the same time, the detection signal Sdet is not referenced between t2 and t3; therefore, High/Low may be uncertain.
    [000138] Next, at t3, when the control signal S5 and the control signal S6 change from Low to High, the IDET electric current and the ITHSET electric current are pulled again, and the High/Low state decision of the signal control S3 is performed again. In the present example, SW3 is turned on at time point t3; therefore, the detection signal Sdet goes High, and the control signal S3 goes Low.
    [000139] Next, at t4, when the control signal S5 and the control signal S6 change from High to Low, such as during the first period, the IDET electric current and the ITHSET electric current stop being pulled, and it is Maintenance of the High / Low state of the control signal S3 is performed. By repeating the above operation, the detection of a leakage current and the on-off control of the Light Emitting Diode LED3 are carried out.
    [000140] Even if the voltage V6 rises, the driver IC 30 according to the present embodiment described above considers that a leak is occurring in the switch SW3 until the voltage V6 becomes greater than the threshold voltage value Vth4. In other words, it is considered that the SW3 switch is not short-circuited by the user. Due to this, in a time of leakage occurrence, it is possible to prohibit the operation of the drive circuit 34 and prevent the Light Emitting Diode LED3 from being turned on erroneously.
    [000141] Furthermore, in the case where the control signal S5 and the control signal S6 are High, the driver IC 30 according to the present embodiment draws the IDET electric current and the ITHSET electric current, and detects a leakage current . On the other hand, in the case where the control signal S5 and the control signal S6 are Low, the driver IC 30 draws the IDET electric current and the ITHSET electric current, does not detect a leakage current and maintains the state of the control signal. S3. Due to this, compared to a case where a leakage current is always detected, it is possible to obtain a reduction in energy consumption.
    [000142] Furthermore, in the driver IC 30 according to the present embodiment, the switch SW3 is arranged in an electrical current path from battery B4 (power supply) to Light Emitting Diode LED3 (load); therefore, even if an oxide layer is formed on a surface of switch SW3, a relatively high current of a few hundred milliamps flows in the on time of switch SW3; therefore, it is possible to remove the oxide layer by means of electric current.
    [000143] Furthermore, according to the trigger IC 30 of the present embodiment, by changing a resistance value of the RSINKSET resistor or RTHSET resistor externally connected to the trigger IC 30, it is possible to easily change a level detection to a leakage current. Other modifications
    [000144] At the same time, in addition to the above embodiments, it is possible to add various modifications to the structure of the present invention without departing from the spirit of the present invention. In other words, it is to be understood that the above embodiments are exemplary in all respects and are not limiting, and the technological scope of the present invention is not indicated by the description of the above embodiments, but by the claims, and all modifications within the scope of the claims and the meaning equivalent to the claims are covered. INDUSTRIAL APPLICABILITY
    [000145] The present invention is a technology useful for achieving improved accuracy for detecting a leakage current in charging apparatus such as a microprocessor, a semiconductor apparatus, a lighting apparatus and the like and in a vehicle which assembles the same. LIST OF REFERENCE NUMBERS 10 driver IC (semiconductor apparatus) 11 leakage current detection circuit 12 driver circuit (target control circuit) 13 reference power supply 14 constant current generating circuit 15 voltage generating circuit 16 logic circuit 20 trigger IC (semiconductor device) 21 leakage current detection circuit 22 trigger circuit (target control circuit) 23 constant voltage source 30 trigger IC (semiconductor device) 31 CR timer 32 mirror circuit current 33 logic circuit 34 drive circuit (target control circuit) 100 motorcycle (vehicle) 101 headlight 102 tail light 103 turn signal light 104 turn signal light 105 switch B1, B2, B4 batteries B3, B5 constant voltage sources SW1 , SW2, SW3 switches D1, D2 diodes LED1, LED2, LED3 Light Emitting Diodes (loads) L1 coil IN1, IN2, IN3 external terminals OUT1, OUT2, OUT3 external terminals SE1, SE2 ex terminals VCC1 suits external terminal STIN, THSET, SINKSET external terminals CVCC, CVIN capacitors N1, N2 N-channel type MOS field effect transistors P3 P-channel type MOS field effect transistor P11 P-type MOS field effect transistor P-channel N12 to N14 N-channel type MOS field effect transistors (first transistor, second transistor) N31 N-channel type MOS field effect transistor CMP1, CMP2, CMP3 comparators OPA1, OPA2 operational amplifiers CS1 power supply constant current R1 resistor R11a R19 resistors (first resistor to fourth resistor) RTHSET, RSINKSET resistors RSW leakage resistance value Rth threshold resistance value V1 to V6 voltages (input voltages) VIN, VCC, VSE voltages (input voltages) Vth1 a Vth4 voltage threshold values VREG constant voltage Vst voltage enabling operation I1, I2 electrical currents (switching currents) IIN electrical current (switching currents) Ith threshold current value IDET , ITHSET, ISINKSET, ILED electrical currents INV1, INV2 inverters S0 to S6 control signals Sdet detection signal
    权利要求:
    Claims (7)
    [0001]
    1. Leakage current detection circuit (11, 21), comprising; a signal generation detection part that detects a switch current (I1, I2, IIN) flowing in a switch (105, SW1, SW2, SW3) that is addressed for leakage monitoring, and generates a detection signal ( Sdet) to prohibit operation of a control target circuit (12, 22, 34) which is addressed to control when the switch current (I1, I2, IIN) does not reach a predetermined threshold value, in which the fault detection part signal generation (11) detects an input voltage (V1-V6, VIN, VCC, VSE) according to the switch current (I1, I2, IIN), and generates the detection signal (Sdet) to prohibit operation of the target control circuit (12, 22, 34) when the input voltage (V1-V6, VIN, VCC, VSE) does not reach a predetermined voltage threshold value (Vth1-Vth4), the input voltage (V1- V6, VIN, VCC, VSE) is supplied as a drive voltage to the target control circuit (12, 22, 34), and the voltage threshold value (Vth1-Vth4) is determined to be less than a voltage that exists. ill operation (Vst) of the control target circuit (12, 22, 34), and characterized by the fact that the generation signal detection part (11) includes: first, second, and third resistors (R19, R14 , R15) whose first terminals are connected to an application terminal for the input voltage (V1-V6, VIN, VCC, VSE); a first transistor (N13) of N-channel type whose source is connected to a ground terminal, the drain is connected to a second terminal of the first resistor (R1, R11-R19), and the gate is connected to a second terminal of the second resistor (R14); a second transistor (N14) of N-channel type whose source is connected to the ground terminal, the drain is connected to the gate of the first transistor (N13), and the gate is connected to a second terminal of the third resistor (R15); a fourth resistor (R16) whose first terminal is connected to the gate of the second transistor (N1, N2, N31, N12-N14), and the second terminal is connected to the ground terminal; and an output terminal that supplies a voltage, such as the sense signal (Sdet), that appears between the second terminal of the first resistor (R1, R11-R19) and the drain of the first transistor (N13).
    [0002]
    2. Leakage current detection circuit (11), according to claim 1, characterized in that it includes: the switch (105, SW1, SW2, SW3) is arranged in a first electric current path between a load (LED1) driven by the target control circuit (12, 22, 34) and a power supply (B1, CVCC) that applies a voltage to the load.
    [0003]
    3. Semiconductor apparatus (10, 20, 30) comprising: a control target circuit (12, 22, 34) of the leakage current detection circuit (11, 21) which is addressed for control; and characterized in that it further comprises: a leakage current detection circuit (11, 21) as defined in claim 1 or 2.
    [0004]
    4. Semiconductor device (10), according to claim 3, characterized in that the target control circuit (12, 22, 34) is a drive circuit that drives a load (LED1).
    [0005]
    5. Semiconductor device (10), according to claim 4, characterized in that the load (LED1) is an LED (Light Emitting Diode).
    [0006]
    6. LED lighting fixture comprising: an LED (LED1, LED2, LED3); and characterized in that it further comprises: a semiconductor device (10, 20, 30) as defined in claim 5, which performs LED activation control (LED1, LED2, LED3).
    [0007]
    7. Vehicle (100), comprising: a headlamp (101); a tail light (102); and a turn signal (103, 104), characterized in that at least one of headlight (101), tail light (102) and turn signal (103, 104) is an LED lighting apparatus as defined in claim 6.
    类似技术:
    公开号 | 公开日 | 专利标题
    BR102013021176B1|2022-01-11|LEAKAGE CURRENT DETECTION CIRCUIT, SEMICONDUCTOR APPLIANCE, LED LIGHTING APPLIANCE, AND VEHICLE
    JP6641080B2|2020-02-05|Light emitting element driving device, light emitting device, vehicle
    US20120326632A1|2012-12-27|Semiconductor light source lighting circuit
    CN102891467A|2013-01-23|Led short circuit protection
    US20150028774A1|2015-01-29|Light-emitting element lighting device, light-emitting module, illuminating apparatus, and light-emitting element lighting method
    JP2004119422A|2004-04-15|Light emitting device drive circuit
    EP2958404B1|2017-09-06|Led illumination dimming circuit and led illumination dimming method
    JP6037164B2|2016-11-30|Power supply circuit and lighting device
    JP2010171199A|2010-08-05|Light emitting diode driving device and lighting instrument using the same, in-cabin lighting device, and lighting device for vehicle
    JP5635209B1|2014-12-03|Lamp driving power source and control method of lamp driving power source
    JP6202970B2|2017-09-27|Inrush current prevention circuit and power supply device
    JP2009219176A5|2010-12-24|
    ES2681885T3|2018-09-17|Load circuit for a converter
    JP2013229233A|2013-11-07|Emergency lighting device
    US10057949B2|2018-08-21|Signal transmitting device, signal receiving device, lighting system, illumination fixture, and illumination system
    JP2018185963A|2018-11-22|Light-emitting element drive device and driving method thereof
    JP6237301B2|2017-11-29|Lighting device and lighting apparatus
    CN212381445U|2021-01-19|LED drive circuit
    JP5060852B2|2012-10-31|Semiconductor device
    JP6130045B1|2017-05-17|Vehicle switch detection circuit and method for controlling vehicle switch detection circuit
    US9101016B2|2015-08-04|LED illuminating apparatus having enhanced quantity of light
    JP2016170975A|2016-09-23|Lighting circuit and illumination system
    JP2017010728A|2017-01-12|Lighting device and lighting equipment
    CN111787665A|2020-10-16|LED drive circuit
    CN110958743B|2021-06-15|Circuit and method for protecting open circuit and short circuit to ground
    同族专利:
    公开号 | 公开日
    JP2014040142A|2014-03-06|
    US20140055031A1|2014-02-27|
    BR102013021176A2|2014-12-09|
    US9351369B2|2016-05-24|
    JP5989455B2|2016-09-07|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JP3249396B2|1996-07-04|2002-01-21|東芝マイクロエレクトロニクス株式会社|Dynamic circuit|
    JP4039623B2|2002-11-25|2008-01-30|本田技研工業株式会社|Light-emitting diode lighting circuit|
    JP2008213813A|2007-02-05|2008-09-18|Yamaha Motor Co Ltd|Light emitting element lighting circuit and saddle-riding type vehicle|
    US7911263B2|2009-06-30|2011-03-22|International Business Machines Corporation|Leakage current mitigation in a semiconductor device|
    JP2011051381A|2009-08-31|2011-03-17|Stanley Electric Co Ltd|Headlight for vehicle|
    JP2011071174A|2009-09-24|2011-04-07|Renesas Electronics Corp|Semiconductor device and method of detecting characteristic degradation of semiconductor device|
    JP5425004B2|2010-07-05|2014-02-26|本田技研工業株式会社|Light-emitting diode lighting circuit for saddle riding type vehicle|US9194918B2|2013-12-12|2015-11-24|Ford Global Technologies, Llc|Leakage detection circuit with integral circuit robustness check|
    US9826594B2|2014-03-31|2017-11-21|Honda Motor Co., Ltd.|Vehicle LED lighting device system|
    JP6290070B2|2014-11-26|2018-03-07|新電元工業株式会社|Driver circuit and driver circuit control method|
    CA2927030C|2015-02-23|2017-11-07|Isao Ohki|Led driver circuit|
    KR102051694B1|2015-03-16|2019-12-04|매그나칩 반도체 유한회사|Leakage currrent detection circuit, light apparatus comprising the same and leakage currrent detection method|
    WO2017051475A1|2015-09-25|2017-03-30|新電元工業株式会社|Vehicle switch detection circuit and method for controlling vehicle switch detection circuit|
    DE102015219903B4|2015-10-14|2017-11-16|Continental Automotive Gmbh|Method and circuit device for detecting a failure of at least one light emitting diode in a light emitting diode array|
    JP6540896B2|2016-06-02|2019-07-10|株式会社村田製作所|Battery module voltage control device, battery module and power supply system|
    KR20180035067A|2016-09-28|2018-04-05|에스케이하이닉스 주식회사|Voltage generation circuit and semiconductor device|
    CN109617005B|2017-02-17|2021-02-02|杰华特微电子（杭州）有限公司|Leakage protection circuit and lighting driving circuit|
    CN107069648B|2017-03-22|2019-03-29|广州炫通电气科技有限公司|Earth leakage protecting method|
    CN108901096B|2018-05-23|2020-08-04|泉芯电子技术有限公司|Detection control circuit and method for mains supply voltage electric leakage|
    GB2579636A|2018-12-07|2020-07-01|Eaton Intelligent Power Ltd|Circuit breaker|
    JPWO2020121864A1|2018-12-14|2021-11-04|ローム株式会社|Lamp controller|
    EP3715884A1|2019-03-29|2020-09-30|Automotive Lighting Italia S.p.A.|Automobile lighting unit with oled light sources and related operating method|
    KR102232191B1|2019-12-11|2021-03-25|주식회사 유라코퍼레이션|Switch control system and method having fail safety functions|
    法律状态:
    2014-12-09| B03A| Publication of a patent application or of a certificate of addition of invention [chapter 3.1 patent gazette]|
    2018-11-21| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-12-31| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2021-07-06| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|
    2021-11-09| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2022-01-11| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 19/08/2013, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    JP2012-182494|2012-08-21|
    JP2012182494A|JP5989455B2|2012-08-21|2012-08-21|Leak current detection circuit, semiconductor device, LED lighting device, vehicle|
    [返回顶部]