Switch control device, switch device, engine ignition device, and vehicle

Abstract

This switch control device is provided with: a signal generation circuit configured to generate a second control signal corresponding to a first control signal; a switch element driving control circuit configured to drive and control a switch element according to the second control signal; a first ground electrode configured to be connected to a first end of the switch element; and a second ground electrode separated from the first ground electrode. The signal generation circuit includes a conversion circuit configured to convert a first voltage representing the difference between a reference voltage and the potential of the first ground electrode into a second voltage representing the difference between a voltage corresponding to the reference voltage and the potential of the second ground electrode.

Description

Switch control device, switch device, engine ignition device, and vehicle

[0001] The invention disclosed herein relates to a switch control device, a switch device, an engine ignition device, and a vehicle.

[0002] An igniter is a type of switch device that includes a switch element and a switch control device. In the igniter, the switch control device controls the switch element to control a primary voltage of an ignition coil connected to an ignition plug of an engine (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2020-101152

[0004] In a switch control device, it is desirable that the current flowing through the switch element does not affect the control of the switch element. From the viewpoint of cost, etc., a switch control device that can prevent the current flowing through the switch element from affecting the control of the switch element with a simple circuit configuration is desirable.

[0005] A switch control device disclosed in this specification includes a signal generating circuit configured to generate a second control signal in response to a first control signal, a switch element drive control circuit configured to drive and control a switch element in response to the second control signal, a first ground electrode configured to be connected to a first end of the switch element, and a second ground electrode separated from the first ground electrode, The signal generating circuit includes a conversion circuit configured to convert a first voltage that is a difference between a reference voltage and a potential of the first ground electrode into a second voltage that is a difference between a voltage in response to the reference voltage and a potential of the second ground electrode.

[0006] The switch device disclosed in this specification includes the switch control device having the above-described configuration and the switch element.

[0007] The engine ignition device disclosed in this specification comprises an igniter which is a switch device having the above-described configuration, an ignition coil including a primary coil connected to the second end of the switch element and a secondary coil, and an ignition plug connected to the secondary coil.

[0008] The vehicle disclosed in this specification is equipped with the engine ignition device having the above-described configuration.

[0009] According to the invention disclosed in this specification, it is possible to prevent the current flowing through the switch element from affecting the control of the switch element with a simple circuit configuration.

[0010] FIG. 1 is a diagram showing the configuration of an engine ignition device according to a first comparative example. FIG. 2 is a timing chart showing the operation sequence of an igniter according to the first comparative example. FIG. 3 is a diagram showing the configuration of an engine ignition device according to a second comparative example and an embodiment. FIG. 4 is a timing chart showing the operation sequence of an igniter according to the second comparative example and an embodiment. FIG. 5 is a diagram showing the configuration of a signal generation circuit according to the second comparative example. FIG. 6 is a diagram showing the configuration of a signal generation circuit according to an embodiment. FIG. 7 is a diagram showing an example configuration of a level shift circuit. FIG. 8 is a diagram showing a modified example of the level shift circuit. FIG. 9 is a diagram showing a modified example of the level shift circuit. FIG. 10 is a diagram showing an example configuration of a vehicle.

[0011] <1. First Comparative Example> First, before describing the embodiment according to the present disclosure, a first comparative example and a second comparative example will be described in order. Comparison with the first comparative example and the second comparative example will clarify the advantageous effects of the embodiment according to the present disclosure.

[0012] <1-1. Overall Configuration> Fig. 1 is a diagram showing the configuration of an engine ignition device 1 according to a first comparative example. As means for driving a gasoline engine (not shown), the engine ignition device 1, a power source 2, and an engine control unit 3 (hereinafter abbreviated as ECU (engine control unit) 3) are mounted on a vehicle. The power source 2 is configured as a car battery.

[0013] The engine ignition device 1 operates by receiving power supply from a power source 2. The engine ignition device 1 is a means for igniting fuel (a mixture of gasoline and air) inside the gasoline engine in response to an ignition command signal IGT from an ECU 3. The engine ignition device 1 has an igniter 10, an ignition coil 20, and a spark plug 30.

[0014] The igniter 10 is a switch device including a switch element chip 11 and a switch control device 12. The igniter 10 is a means for turning on / off the primary coil current (corresponding to the collector current Ic of the switch element 111 described later) of the ignition coil 20. The igniter 10 is provided as a semiconductor integrated circuit device in which the switch element chip 11 and the switch control device 12 are packaged.

[0015] The switch control device 12 is configured by integrating a signal generating circuit 121, a switch element drive control circuit 122, and a current detecting circuit 123 on a single semiconductor chip. The switch control device 12 also has a function of generating a gate signal Sg for the switch element 111 (described later) in response to an ignition command signal IGT from the ECU 3. The switch control device 12 also has a function of detecting the primary coil current of the ignition coil 20.

[0016] The switch element chip 11 is configured by integrating a switch element 111 and a shunt resistor 112 on a single semiconductor chip. The switch element 111 is turned on / off by a switch control device 12, and in this example, an insulated gate bipolar transistor (IGBT) is used. The switch element 111 has a gate connected to the switch control device 12, a collector connected to the primary coil 21 of the ignition coil 20, and an emitter connected to a terminal to which a ground potential is applied. Note that instead of the IGBT, a metal oxide semiconductor field effect transistor (MOSFET), for example, may be used as the switch element 111. The shunt resistor 112 is an element for detecting the primary coil current of the ignition coil 20.

[0017] The ignition coil 20 includes a primary coil 21 with a number of windings M1 and a secondary coil 22 with a number of windings M2 (>M1). The ignition coil 20 serves to convert (boost) an input voltage (= power supply voltage Vdd) supplied from a power supply 2 to a higher output voltage. A first end of the primary coil 21 and a first end of the secondary coil 22 are both connected to an output end (= application end of power supply voltage Vdd) of the power supply 2. A second end of the primary coil 21 is connected to the collector of the switch element 111. A second end of the secondary coil 22 is connected to an ignition plug 30. The output voltage generated at the second end of the secondary coil 22 is supplied to the ignition plug 30.

[0018] The spark plug 30 uses the high voltage obtained by the ignition coil 20 to generate a spark for igniting fuel injected into the engine (not shown).

[0019] The power supply 2 supplies power to various electrical components mounted on the vehicle, including the engine ignition device 1 .

[0020] The ECU 3 executes various controls related to the operation of the vehicle engine. In particular, as one of the various controls, the ECU 3 outputs an ignition instruction signal IGT (= a pulse signal driven by PWM (pulse width modulation)) used to control the operation of the igniter 10 (particularly the switch control device 12). More specifically, when the ECU 3 turns on the switch element 111, the ignition instruction signal IGT has an on-state logic level (e.g., high level), and when the ECU 3 turns off the switch element 111, the ignition instruction signal IGT has an off-state logic level (e.g., low level).

[0021] <1-2. Configuration of Igniter> Here, a more specific configuration of the igniter 10 will be described.

[0022] As described above, the switch element chip 11 includes the switch element 111 and the shunt resistor 112. The switch element chip 11 also includes a collector pad Pc, an emitter pad Pe, a gate pad Pg1, and a shunt pad Psr1 as electrode pads for establishing electrical connection with the outside.

[0023] The collector of the switch element 111 is connected to a second end of the primary coil 21 via a collector pad Pc. The emitter of the switch element 111 is connected to ground potential via a shunt resistor 112, an emitter pad Pe, and a harness (not shown). A resistor 4 in FIG. 1 is a resistance component of the harness connecting the power supply 2 and the ECU 3 to the igniter 10. The gate of the switch element 111 is connected to the switch control device 12 via a gate pad Pg1. When the switch element 111 is in the on state, a collector current Ic flows from the primary coil 21 to ground potential via the collector pad Pc, the switch element 111, the emitter pad Pe, and a harness (not shown).

[0024] The connection node between the emitter of the switch element 111 and the shunt resistor 112 is connected to the switch control device 12 via a shunt pad Psr1.

[0025] As described above, the switch control device 12 includes the signal generating circuit 121, the switch element drive control circuit 122, and the current detecting circuit 123. The switch control device 12 also includes the power supply pad Pvdd, the input pad Pin, the gate pad Pg2, the shunt pad Psr2, and the ground pad Ppgnd as electrode pads for establishing electrical connection with the outside. The power supply voltage Vdd output from the power supply 2 is applied to the power supply pad Pvdd.

[0026] The signal generating circuit 121 generates a control signal Scmp according to the ignition instruction signal IGT input via the input pad Pin from the ECU 3. Specifically, when the ignition instruction signal IGT is at an ON logical level, a high-level control signal Scmp is generated, and when the ignition instruction signal IGT is at an OFF logical level, a low-level control signal Scmp is generated.

[0027] The switch element drive control circuit 122 generates a gate signal Sg by power-amplifying the control signal Scmp. The gate pads Pg2 and Pg1 are connected by a bonding wire W1. As a result, the gate signal Sg is supplied to the gate of the switch element 111 via the gate pads Pg2 and Pg1. When the gate signal Sg is at a high level, the switch element 111 is turned on, and when the gate signal Sg is at a low level, the switch element 111 is turned off.

[0028] The shunt pads Psr1 and Psr2 are connected by a bonding wire W2. The current detection circuit 123 determines the potential difference across the shunt resistor 112 from the voltage applied to the shunt pad Psr2 and the voltage applied to the ground pad Ppgnd, and detects the primary coil current of the ignition coil 20 based on the potential difference across the shunt resistor 112. The current detection circuit 123 outputs an overcurrent detection signal to the switch element drive control circuit 122 when the primary coil current of the ignition coil 20 exceeds a threshold. While receiving the overcurrent detection signal, the switch element drive control circuit 122 fixes the gate signal Sg to a low level regardless of the level of the control signal Scmp. This turns off the switch element 111 in the event of an overcurrent state, preventing the collector current Ic from flowing.

[0029] 2 is a timing chart showing the operation sequence of the igniter 10. In FIG. 2, from the top to the bottom, example waveforms of the ignition instruction signal IGT, the collector current Ic, the voltage PGND applied to the ground pad Ppgnd, and the potential difference (IGT-PGND) between the ignition instruction signal IGT and the voltage PGND are shown.

[0030] As shown in FIG. 2, when the ignition instruction signal IGT switches from low level to high level, the potential difference (IGT-PGND) between the ignition instruction signal IGT and the voltage PGND becomes high level, the control signal Scmp and therefore the gate signal Sg become high level, the switch element 111 becomes on, and the collector current Ic starts to flow.

[0031] While the ignition command signal IGT is at a high level, the collector current Ic increases, and the voltage PGND rises due to the influence of the collector current Ic and the resistor 4 while the ignition command signal IGT is at a high level.

[0032] Due to the layout of components inside the vehicle, the power supply 2 and the ECU 3 may be installed far away from the engine ignition device 1. The longer the distance between the power supply 2 and the ECU 3 and the engine ignition device 1, the greater the resistance value of the resistor 4, and the greater the increase in the voltage PGND.

[0033] When the voltage PGND rises, the potential difference (IGT-PGND) between the ignition instruction signal IGT and the voltage PGND drops. The signal generating circuit 121 generates the control signal Scmp based on the potential difference (IGT-PGND) between the ignition instruction signal IGT and the voltage PGND. Therefore, if the potential difference (IGT-PGND) between the ignition instruction signal IGT and the voltage PGND drops too much, in the worst case scenario, the switch element 111 will be turned off even though the ignition instruction signal IGT is at a high level.

[0034] 3 is a diagram showing the configuration of an engine ignition device 1 according to a second comparative example. The engine ignition device 1 according to the second comparative example is an engine ignition device that can solve the above-mentioned problems.

[0035] In the engine ignition device 1 according to the second comparative example, an improvement has been made to the switch control device 12 compared to the engine ignition device 1 according to the first comparative example.

[0036] Here, in the engine ignition device 1 according to the second comparative example, the description of the same parts as those in the first comparative example will be omitted as appropriate, and the description will focus mainly on the parts that are different from those in the first comparative example.

[0037] The switch control device 12 includes a ground pad Psgnd that is separate from the ground pad Ppgnd. In the second comparative example, a first harness (not shown) is provided for connecting the power supply 2 to the ground pad Ppgnd, and a second harness (not shown) is provided for connecting the power supply 2 and the ECU 3 to the ground pad Psgnd. The resistor 4 in Fig. 3 is the resistance component of the first harness described above. The resistor 5 in Fig. 3 is the resistance component of the second harness described above.

[0038] 4 is a timing chart showing the operation sequence of the igniter 10. In FIG. 4, from the top to bottom, waveform examples of the ignition instruction signal IGT, the collector current Ic, the voltage PGND applied to the ground pad Ppgnd, the voltage SGND applied to the ground pad Psgnd, and the potential difference (IGT-sGND) between the ignition instruction signal IGT and the voltage SGND are shown.

[0039] As shown in FIG. 4, when the ignition instruction signal IGT switches from low level to high level, the potential difference (IGT-SGND) between the ignition instruction signal IGT and the voltage SGND becomes high level, the control signal Scmp and therefore the gate signal Sg become high level, the switch element 111 becomes on, and the collector current Ic starts to flow.

[0040] While the ignition command signal IGT is at a high level, the collector current Ic increases, and the voltage PGND rises due to the influence of the collector current Ic and the resistor 4 while the ignition command signal IGT is at a high level.

[0041] On the other hand, because the signal generating circuit 121 does not include a power element, the current consumption of the signal generating circuit 121 is very small compared to the collector current Ic. Therefore, the change in voltage SGND due to the influence of the current consumption of the signal generating circuit 121 and the resistor 5 is small. As a result, the waveform of the potential difference (IGT-SGND) between the ignition instruction signal IGT and the voltage SGND is substantially the same as the waveform of the ignition instruction signal IGT.

[0042] As is clear from the above description, the engine ignition device 1 according to the second comparative example can solve the problems that the engine ignition device 1 according to the first comparative example has.

[0043] FIG. 5 is a diagram showing the configuration of a signal generating circuit 121 provided in the engine ignition device 1 according to the second comparative example.

[0044] The signal generating circuit 121 shown in FIG. 5 includes a bandgap reference voltage circuit 1211, a reference voltage circuit 1212, resistors R1 to R5, a diode D1, a capacitor C1, and a comparator CMP1.

[0045] The ground voltage application terminal of the bandgap reference voltage circuit 1211 is connected to the ground pad Ppgnd. The voltage PGND applied to the ground pad Ppgnd is the ground voltage of the entire semiconductor chip substrate of the switch control device 12. The bandgap reference voltage circuit 1211 generates a bandgap reference voltage V_BG that is higher than the voltage PGND by a predetermined value, and supplies the bandgap reference voltage V_BG to each component of the switch control device 12.

[0046] The potential difference (IGT-SGND) between the ignition instruction signal IGT supplied to the input pad Pin and the voltage SGND applied to the ground pad Psgnd is divided by resistors R1 and R2, and after noise components are removed by a filter circuit formed by resistor R5 and capacitor C1, the voltage difference is supplied to the non-inverting input terminal of the comparator CMP1.

[0047] A first end of the resistor R1 is connected to the input pad Pin. A second end of the resistor R1 is connected to a first end of the resistor R2 and a first end of the resistor R5. A second end of the resistor R5 is connected to a first end of the capacitor C1 and a non-inverting input terminal of the comparator CMP1.

[0048] The second end of resistor R2, the second end of capacitor C1, the first end of resistor R3, and the first ground voltage application end of reference voltage circuit 1212 are connected to ground pad Psgnd. The second end of resistor R3 is connected to the anode of diode D1. The cathode of diode D1 is connected to the second ground voltage application end of reference voltage circuit 1212, the ground voltage application end of comparator CMP1, and ground pad Ppgnd.

[0049] The reference voltage V_REF output from the reference voltage circuit 1212 is supplied to the inverting input terminal of the comparator CMP1 via a resistor R4. The power supply voltage VDD is applied to the power supply voltage application terminal of the comparator CMP1. The comparator CMP1 outputs a signal Scmp, which is the result of comparing the reference voltage V_REF with a voltage based on the potential difference (IGT-SGND) between the ignition instruction signal IGT and the voltage SGND.

[0050] The reference voltage circuit 1212 requires a circuit design that takes into consideration the voltage PGND applied to the ground pad Ppgnd and the voltage SGND applied to the ground pad Psgnd, which makes the circuit configuration complex, and as a result, the circuit configuration of the switch control device 12 also becomes complex.

[0051] 3. Embodiment The engine ignition device 1 according to the embodiment is an engine ignition device that can solve the above-mentioned problems and has a switch control device 12 with a simple circuit configuration.

[0052] The overall configuration of the engine ignition device 1 according to this embodiment is the same as the overall configuration of the engine ignition device 1 according to the second comparative example, as shown in FIG.

[0053] The timing chart showing the operation sequence of the igniter 10 in this embodiment is the timing chart shown in FIG. 4, similar to the timing chart showing the operation sequence of the igniter 10 in the second comparative example.

[0054] FIG. 6 is a diagram showing the configuration of a signal generating circuit 121 provided in the engine ignition device 1 according to the embodiment.

[0055] The signal generating circuit 121 shown in FIG. 6 includes a bandgap reference voltage circuit 1211, a level shift circuit 1213, resistors R1 to R5, a diode D1, a capacitor C1, and a comparator CMP1.

[0056] The ground voltage application terminal of the bandgap reference voltage circuit 1211 is connected to the ground pad Ppgnd. The voltage PGND applied to the ground pad Ppgnd is the ground voltage of the entire semiconductor chip substrate of the switch control device 12. The bandgap reference voltage circuit 1211 generates a bandgap reference voltage V_BG that is higher than the voltage PGND by a predetermined value, and supplies the bandgap reference voltage V_BG to each component of the switch control device 12. Each component of the switch control device 12 includes a level shift circuit 1213.

[0057] The potential difference (IGT-SGND) between the ignition instruction signal IGT supplied to the input pad Pin and the voltage SGND applied to the ground pad Psgnd is divided by resistors R1 and R2, and noise components are removed by a filter circuit formed by a resistor R5 and a capacitor C1 before the potential difference is supplied to the non-inverting input terminal of the comparator CMP1. Note that if the level of the ignition instruction signal IGT is small and voltage division is not necessary, a configuration may be adopted in which the input pad Pin is connected to the first end of the resistor R5 without providing the resistors R1 and R2.

[0058] A first end of the resistor R1 is connected to the input pad Pin. A second end of the resistor R1 is connected to a first end of the resistor R2 and a first end of the resistor R5. A second end of the resistor R5 is connected to a first end of the capacitor C1 and a non-inverting input terminal of the comparator CMP1.

[0059] The second end of resistor R2, the second end of capacitor C1, the first end of resistor R3, and the first ground voltage application end of reference voltage circuit 1212 are connected to ground pad Psgnd. The second end of resistor R3 is connected to the anode of diode D1. The cathode of diode D1 is connected to the second ground voltage application end of reference voltage circuit 1212, the ground voltage application end of comparator CMP1, and ground pad Ppgnd.

[0060] The level shift circuit 1213 converts the voltage that is the difference between the bandgap reference voltage V_BG and the voltage PGND applied to the ground pad Ppgnd into a reference voltage V_REF that corresponds to the difference between the bandgap reference voltage V_BG and the voltage SGND applied to the ground pad Psgnd. The reference voltage V_REF output from the level shift circuit 1213 is supplied to the inverting input terminal of the comparator CMP1 via a resistor R4. The power supply voltage VDD is applied to the power supply voltage application terminal of the comparator CMP1. The comparator CMP1 outputs a signal Scmp that is the result of comparing the reference voltage V_REF with a voltage based on the potential difference (IGT-SGND) between the ignition instruction signal IGT and the voltage SGND.

[0061] The signal Scmp output from the comparator CMP1 is supplied to the level shift circuit 1213 in addition to the switch element drive control circuit 122. The level shift circuit 1213 uses the signal Scmp to realize a hysteresis characteristic.

[0062] The level shift circuit 1213 is a circuit that simply shifts the reference level from voltage PGND to voltage SGND, and therefore has a simple circuit configuration, which results in a simpler circuit configuration for the switch control device 12.

[0063] Fig. 7 is a diagram showing an example of the configuration of the level shift circuit 1213. The level shift circuit 1213 shown in Fig. 7 includes a voltage / current conversion circuit VI1, a current mirror circuit CM1, and a current / voltage conversion circuit IV1.

[0064] The voltage / current conversion circuit VI1 converts the bandgap reference voltage V_BG into a first current corresponding to the difference between the bandgap reference voltage V_BG and a voltage PGND applied to the ground pad Ppgnd. The voltage / current conversion circuit VI1 includes resistors R11 to R13, a PNP transistor Q11, an NPN transistor Q12, and an N-channel MOS field effect transistor Q15.

[0065] A power supply voltage VDD, for example, is applied to a first terminal of the resistor R11. A second terminal of the resistor R11 is connected to the emitter of the PNP transistor Q11 and the base of the NPN transistor Q12. A bandgap reference voltage V_BG is applied to the base of the PNP transistor Q11. The emitter of the NPN transistor Q12 is connected to a first terminal of the resistor R12. A second terminal of the resistor R12 is connected to a first terminal of the resistor R13 and the drain of the N-channel MOS field effect transistor Q15. A voltage PGND is applied to the collector of the PNP transistor Q11, the second terminal of the resistor R13, and the source of the N-channel MOS field effect transistor Q15. A signal Scmp is supplied to the gate of the N-channel MOS field effect transistor Q15.

[0066] When the signal Scmp is at a low level, the voltage / current conversion circuit VI1 outputs a current whose value is the potential difference between the bandgap reference voltage V_BG and the voltage PGND divided by the resistance value of the combined resistance of the resistors R12 and R13. On the other hand, when the signal Scmp is at a high level, the voltage / current conversion circuit VI1 outputs a current whose value is the potential difference between the bandgap reference voltage V_BG and the voltage PGND divided by the resistance value of the resistor R12.

[0067] The current mirror circuit CM1 generates a mirror current corresponding to the current output from the voltage / current conversion circuit VI1. The current mirror circuit CM1 includes resistors R14 and R15 and PNP transistors Q13 and Q14. Note that in the current mirror circuit CM1, P-channel MOS field effect transistors may be used instead of the PNP transistors Q13 and Q14.

[0068] A power supply voltage VDD, for example, is applied to first ends of resistors R14 and R15. A second end of resistor R14 is connected to the emitter of PNP transistor Q13. A second end of resistor R15 is connected to the emitter of PNP transistor Q14. The base of PNP transistor Q13, the base of PNP transistor Q14, and the collector of PNP transistor Q13 are connected to the collector of NPN transistor Q12.

[0069] The current mirror circuit CM1 outputs a mirror current corresponding to the current output from the voltage / current conversion circuit VI1.

[0070] The current / voltage conversion circuit IV1 converts the mirror current output from the current mirror circuit CM1 into a reference voltage V_REF corresponding to the mirror current, with the voltage SGND as a reference. The current / voltage conversion circuit IV1 includes resistors R16 and R17.

[0071] A first end of the resistor R16 is connected to the collector of the PNP transistor Q14. A second end of the resistor R16 is connected to a first end of a resistor R17. A voltage SGND is applied to a second end of the resistor R17. The voltage at the connection node between the resistors R16 and R17 serves as a reference voltage V_REF.

[0072] It is also possible to remove the resistor R13 and the N-channel MOS field effect transistor Q15 from the level shift circuit 1213, so that the level shift circuit 1213 does not have a hysteresis characteristic.

[0073] On the other hand, instead of giving the level shift circuit 1213 hysteresis characteristics by changing the conversion ratio of the voltage / current conversion circuit VI1 as shown in Fig. 7, the level shift circuit 1213 may be given hysteresis characteristics by changing the mirror ratio of the current mirror circuit CM1 as shown in Fig. 8, or the level shift circuit 1213 may be given hysteresis characteristics by changing the conversion ratio of the current / voltage conversion circuit IV1 as shown in Fig. 9. Furthermore, the level shift circuit 1213 may be given hysteresis characteristics by combining at least two of the level shift circuits 1213 shown in Figs. 7 to 9.

[0074] However, since the reference of the comparator CMP1 is the voltage PGND, it is desirable that the signal Scmp be supplied to a circuit that uses the voltage PGND as a reference. Therefore, the configuration of the level shift circuit 1213 shown in FIG.

[0075] 4. Vehicle FIG. 10 is a diagram showing an example of the configuration of a vehicle on which the engine ignition device 1 according to the embodiment is mounted.

[0076] FIG. 10 is a diagram showing an example of the configuration of a vehicle equipped with the engine ignition device 1 according to the embodiment.

[0077] The vehicle X1 shown in Figure 10 includes the power supply 2 and ECU 3 described above, an engine unit 61 with a generator, a high-power DC / DC converter 62, an inverter 63, a motor 64, a drive unit 65, a high-voltage battery 66, and a DC / DC converter 67. For convenience of illustration, the mounting positions of the components in Figure 10 differ from the actual positions. The vehicle X1 shown in Figure 10 is a so-called series hybrid vehicle.

[0078] The generator-equipped engine section 61 includes a generator, a dedicated power generation engine that rotates the generator, and the engine ignition device 1 according to the various embodiments described above. Since the energy conversion efficiency of the engine varies greatly depending on the timing of ignition, the ignition timing must be controlled by the ECU 3 in consideration of the rotation angle of the crank that converts the reciprocating motion of the piston in the cylinder into rotational motion and the required amount of power generation. For this reason, the engine ignition device 1 according to the embodiments is provided for each cylinder of the engine.

[0079] The high-power DC / DC converter 62 converts DC power generated by the generator of the generator-equipped engine unit 61 into high-voltage DC power. The high-power DC / DC converter 62 supplies the high-voltage DC power to the inverter 63 and the high-voltage battery 66. The high-power DC / DC converter 62 can also supply discharge power discharged from the high-voltage battery 66 to the inverter 63. Furthermore, the high-power DC / DC converter 62 can also charge the high-voltage battery 66 with regenerative power supplied from the inverter 63 when the vehicle X1 is decelerating.

[0080] The inverter 63 receives DC power from the high-power DC / DC converter 62 and converts the received DC power into three-phase AC power.

[0081] The motor 64 has a shaft and rotates the shaft using three-phase AC power supplied from the inverter 63 .

[0082] The drive unit 65 transmits power generated by the rotation of the shaft of the motor 64 to the drive wheels of the vehicle X1. Note that, although the rear wheels of the vehicle X1 are drive wheels in Fig. 10, the drive wheels are not limited to the rear wheels. In other words, the front wheels may be drive wheels, or both the front and rear wheels may be drive wheels.

[0083] The DC / DC converter 67 receives DC power from the high-power DC / DC converter 62 and converts the received DC power into low-voltage DC power. The power supply 2, which is a low-voltage battery, is charged with the low-voltage DC power output from the DC / DC converter 67. The discharge power discharged from the power supply 2 is supplied to the engine ignition device 1 according to the embodiment and the like.

[0084] The vehicle on which the engine ignition device 1 according to the embodiment is mounted is not limited to a hybrid vehicle such as the vehicle X1 shown in FIG. 10, but may be any vehicle equipped with an engine.

[0085] <5. Others> Various modifications can be made to the embodiments of the present disclosure as appropriate within the scope of the technical ideas set forth in the claims. The various embodiments and modifications described so far may be combined as appropriate within a consistent scope. The above-described embodiments are merely examples of embodiments of the present disclosure, and the meanings of the terms in the present disclosure and each constituent element are not limited to those described in the above embodiments.

[0086] For example, in the above-described embodiment, the bandgap reference voltage V_BG is supplied to the level shift circuit 1213, but the reference voltage supplied to the level shift circuit 1213 may be a reference voltage other than the bandgap reference voltage, as long as it is a reference voltage generated based on the voltage PGND.

[0087] For example, in the above-described embodiment, the igniter 10 has been described as an example of a switch device, but the switch device may be a switch device other than the igniter 10. An example of a switch device other than the igniter 10 is a load switch connected in series to a load.

[0088] <6. Supplementary Notes> Supplementary notes are provided for the present disclosure, the specific configuration examples of which have been shown in the above-described embodiments.

[0089] The switch control device (12) of the present disclosure includes a signal generating circuit (121) configured to generate a second control signal in response to a first control signal, a switch element drive control circuit (122) configured to drive and control a switch element (111) in response to the second control signal, a first ground electrode (Ppgnd) configured to be connected to a first end of the switch element, and a second ground electrode (Psgnd) separated from the first ground electrode, and the signal generating circuit has a configuration (first configuration) including a conversion circuit (1213) configured to convert a first voltage, which is the difference between a reference voltage and the potential of the first ground electrode, into a second voltage, which is the difference between a voltage in response to the reference voltage and the potential of the second ground electrode.

[0090] In the switch control device of the first configuration, the signal generating circuit may be configured (second configuration) to include a comparator (CMP1) configured to compare the second voltage with a third voltage based on the first control signal.

[0091] In the switch control device of the first or second configuration, the conversion circuit may be configured (third configuration) to include: a voltage / current conversion circuit (VI1) configured to convert the reference voltage into a first current corresponding to a difference between the reference voltage and the potential of the first ground electrode; a current mirror circuit (CM1) configured to generate a second current corresponding to the first current; and a current / voltage conversion circuit (IV1) configured to convert the second current into the second voltage corresponding to the second current, with the potential of the second ground electrode as a reference.

[0092] The switch control device of the third configuration may be configured (fourth configuration) such that at least one of the conversion ratio of the voltage / current conversion circuit, the mirror ratio of the current mirror circuit, and the conversion ratio of the current / voltage conversion circuit is changeable.

[0093] The switch control device of the fourth configuration may be configured so that the conversion ratio of the voltage / current conversion circuit is changeable (fifth configuration).

[0094] A switch device (10) of the present disclosure has a configuration (sixth configuration) including a switch control device of any one of the first to fifth configurations and the switch element.

[0095] The engine ignition device (1) of the present disclosure has a configuration (seventh configuration) that includes an igniter which is a switch device of the sixth configuration described above, an ignition coil (20) including a primary coil (21) connected to the second end of the switch element and a secondary coil (22), and an ignition plug (20) connected to the secondary coil.

[0096] The vehicle (X1) of the present disclosure has a configuration (eighth configuration) that includes the engine ignition device of the seventh configuration described above.

[0097] REFERENCE SIGNS LIST 1 engine ignition device 2 power supply 3 engine control unit 4 resistor 10 igniter 11 switch element chip 12 switch control device 20 ignition coil 21 primary coil 22 secondary coil 30 spark plug 61 engine part with generator 62 high-power DC / DC converter 63 inverter 64 motor 65 drive device 66 high-voltage battery 67 DC / DC converter 111 switch element 112 shunt resistor 121 signal generation circuit 122 switch element drive control circuit 123 current detection circuit 1211 band gap reference voltage circuit 1212 reference voltage circuit 1213 level shift circuit C1 capacitor CM1 current mirror circuit CMP1 comparator D1 diode IV1 current / voltage conversion circuit Pc collector pad Pe emitter pad Pin input pad Pg1, Pg2 Gate pads Psr1, Psr2 Shunt pads Pvdd Power supply pad Ppgnd Ground pad Q11, Q13, Q14 PNP transistor Q12 NPN transistor Q15 N-channel MOS field effect transistor R1 to R5, R11 to R17 Resistors VI1 Voltage / current conversion circuit X1 Vehicle

Claims

1. a signal generating circuit configured to generate a second control signal in response to the first control signal; a switch element drive control circuit configured to drive and control the switch element in response to the second control signal; a first ground electrode configured to be connected to a first end of the switch element; a second ground electrode separate from the first ground electrode; Equipped with The signal generating circuit includes a conversion circuit configured to convert a first voltage, which is a difference between a reference voltage and the potential of the first ground electrode, into a second voltage, which is a difference between a voltage corresponding to the reference voltage and the potential of the second ground electrode.

2. The switch control device according to claim 1 , wherein the signal generating circuit includes a comparator configured to compare the second voltage with a third voltage based on the first control signal.

3. The conversion circuit a voltage / current conversion circuit configured to convert the reference voltage into a first current corresponding to a difference between the reference voltage and a potential of the first ground electrode; a current mirror circuit configured to generate a second current responsive to the first current; a current / voltage conversion circuit configured to convert the second current into the second voltage corresponding to the second current with respect to a potential of the second ground electrode; The switch control device of claim 1 , comprising:

4. 4. The switch control device according to claim 3, wherein at least one of the conversion ratio of the voltage / current conversion circuit, the mirror ratio of the current mirror circuit, and the conversion ratio of the current / voltage conversion circuit is changeable.

5. The switch control device according to claim 4 , wherein the conversion ratio of the voltage / current conversion circuit is variable.

6. A switch control device according to any one of claims 1 to 5; The switch element; A switch device comprising:

7. an igniter that is the switch device according to claim 6; an ignition coil including a primary coil connected to a second end of the switch element and a secondary coil; a spark plug connected to the secondary coil; An engine ignition device comprising:

8. A vehicle comprising the engine ignition device according to claim 7.