Circuit arrangement

Abstract

Circuit device. The circuit device includes a control circuit that controls a transistor current in accordance with a detected temperature. The detected temperature is a temperature detected by a temperature sensor circuit that detects a temperature of a transistor. The transistor charges a load supplied with a power supply voltage. The transistor current is a current that flows through the transistor in the charging. The control circuit decreases the transistor current when the detected temperature is higher than a first threshold value, and increases the transistor current when the detected temperature is lower than a second threshold value that is lower than the first threshold value.

Description

TECHNICAL FIELD

[0001] The present application relates to a circuit device or the like. BACKGROUND

[0002] Patent Literature 1 discloses a power supply unit that suppresses an adverse situation due to heat generation of a field effect transistor provided in a surge current prevention circuit. The power supply unit includes a first power supply that supplies a first voltage to a load, and a surge current prevention circuit. The surge current prevention circuit suppresses a surge current by shunting an output current of the first power supply to a load side different from the load supplied with the first voltage. The surge current prevention circuit includes the field effect transistor and a thermistor that measures a temperature of the field effect transistor, and in a case where it is determined that the temperature of the field effect transistor is an alarm temperature, the field effect transistor is made to be in a driving stop state.

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2018-072498

[0004] There is a problem of suppressing heat generation of a transistor that charges a load or a transistor that discharges a load, and charging or discharging the load as fast as possible by a current flowing through the transistor. In Patent Literature 1 described above, the output current of the first power supply is shunted to a load side different from the load supplied with the first voltage, and thus even if a current flows through the field effect transistor, charging of the load supplied with the first power supply cannot be accelerated. SUMMARY

[0005] One embodiment of the present application relates to a circuit device including a control circuit that controls a transistor current flowing through a transistor in charging of a load supplied with a power supply voltage, in accordance with a detection temperature detected by a temperature sensor circuit that detects a temperature of the transistor. The control circuit decreases the transistor current when the detection temperature is higher than a first threshold value, and increases the transistor current when the detection temperature is lower than a second threshold value lower than the first threshold value.

[0006] Further, another embodiment of the present application relates to a circuit device including a control circuit that controls a transistor current flowing through a transistor in discharging of a load supplied with a power supply voltage, in accordance with a detection temperature detected by a temperature sensor circuit that detects a temperature of the transistor. The control circuit decreases the transistor current when the detection temperature is higher than a first threshold value, and increases the transistor current when the detection temperature is lower than a second threshold value lower than the first threshold value. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a configuration example of a circuit device and an electronic apparatus.

[0008] Figure 2 is a state transition diagram of the control by the control circuit.

[0009] Figure 3 is a first waveform diagram illustrating the operation of the charging circuit.

[0010] Figure 4 is a second waveform diagram illustrating the operation of the charging circuit.

[0011] Figure 5 is a detailed configuration example of the charging circuit.

[0012] Figure 6 is a detailed configuration example of the discharging circuit.

[0013] Figure 7 is a detailed configuration example of the constant current control circuit.

[0014] Figure 8 is a detailed configuration example of the temperature sensor circuit, the reference voltage generation circuit, the high-temperature-side temperature detection circuit, the low-temperature-side temperature detection circuit, and the protection temperature detection circuit.

[0015] Figure 9 is a detailed configuration example of the drive circuit and the gate control circuit.

[0016] Explanation of Reference Signs

[0017] 10: electronic device; 11: external transistor; 12: step-up capacitor; 100: circuit device; 110: regulator; 120: charge pump circuit; 140: reference voltage generation circuit; 160: drive circuit; 162: charge pump control circuit; 170: gate control circuit; 180: charging circuit; 181: high-temperature-side temperature detection circuit; 182: low-temperature-side temperature detection circuit; 183: protection temperature detection circuit; 185: control circuit; 186: state control circuit; 187: constant current control circuit; 188: temperature sensor circuit; 189: transistor; 190: discharging circuit; 191: high-temperature-side temperature detection circuit; 192: low-temperature-side temperature detection circuit; 193: protection temperature detection circuit; 195: control circuit; 196: state control circuit; 197: constant current control circuit; 198: temperature sensor circuit; 199: transistor; 300: load; I1: first current value; I2: second current value; I3: third current value; NLOAD: node; NVCC: power supply node; TH: first threshold value; TL: second threshold value; Tmax: third threshold value; Tmin: fourth threshold value; VCC: power supply voltage; VCO: source voltage; VH: first reference voltage; VL: second reference voltage; VTA, VTB: temperature detection voltage; VTSD: third reference voltage; Vmin: fourth reference voltage; WAIT1: first period; WAIT2: second period. DETAILED DESCRIPTION

[0018] Hereinafter, a preferred embodiment of the present application will be described in detail. In addition, the present embodiment described below is not intended to unduly limit the content recited in the claims, and the structures described in the present embodiment are not necessarily all essential structural elements.

[0019] 1. Circuit device and electronic device

[0020] Figure 1 is a structural example of the circuit device 100 and the electronic device 10 in the present embodiment. The electronic device 10 includes the external transistor 11, the load 300, and the circuit device 100. Hereinafter, the example in which the external transistor 11 is an N-type transistor will be mainly described, but the external transistor 11 can also be a P-type transistor.

[0021] The electronic device 10 can be, for example, a printing device, an image projection device, a wearable device, an information processing device, a display device, a television receiver, a portable information terminal, or the like, but is not limited thereto, and can be various devices that use the direct-current power supply voltage VCC.

[0022] The external transistor 11 is provided between the power supply node NVCC and the load 300. Specifically, the drain of the external transistor 11 is connected to the power supply node NVCC, and the source is connected to a node NLOAD of the load 300. The external transistor 11 is a so-called power transistor that supplies the power supply voltage VCC to the load 300 when turned on, and cuts off the supply of the power supply voltage VCC to the load 300 when turned off.

[0023] The power supply voltage VCC is supplied from a direct-current power supply to the power supply node NVCC. The direct-current power supply is, for example, an AC-DC converter, a DC-DC converter, or a battery. In addition, although not shown in the Figure 1 , these direct-current power supplies can also be included in the electronic device 10.

[0024] The load 300 is a circuit that operates using the power supply voltage VCC supplied to the node NLOAD via the external transistor 11. The node NLOAD is a power supply node of the load 300. The load 300 is, for example, a power supply stabilizing capacitor provided between the node NLOAD and a ground voltage GND, a processing device that performs processing in the electronic device 10, or a motor driver that drives a motor, or the like. In addition, the load 300 is not limited thereto, and can be a circuit for realizing various functions in the electronic device 10.

[0025] The circuit device 100 outputs a gate control voltage DRV to the gate of the external transistor 11, and thereby controls the supply of the power supply voltage VCC to the load 300. The circuit device 100 includes a regulator 110, a charge pump circuit 120, a charging circuit 180, a discharging circuit 190, and terminals TCHP1, TCHP, TVCC, TDRV, TVCO, and TDIS. The circuit device 100 is, for example, an integrated circuit device in which a plurality of circuit elements are integrated on a semiconductor substrate. Each terminal is, for example, a pad of the integrated circuit device or a terminal of a package that houses the integrated circuit device.

[0026] The regulator 110 outputs a regulated voltage VRG by regulating the power supply voltage VCC from the power supply node NVCC. The terminal TVCC is connected to the power supply node NVCC, and the power supply voltage VCC is supplied to the regulator 110 via the terminal TVCC. The regulator 110 is a step-down regulator that outputs a regulated voltage VRG lower than the power supply voltage VCC. The regulator 110 is, for example, a linear regulator, but is not limited thereto, and can be a DC-DC converter of various types.

[0027] The charge pump circuit 120 boosts the regulation voltage VRG based on the source voltage VCO of the external transistor 11, outputting a gate control voltage DRV = VCO + VRG, which is higher than the source voltage VCO. Consequently, when the charge pump circuit 120 is operating, the external transistor 11 is turned on, and the power supply voltage VCC is supplied to the load 300 via the external transistor 11.

[0028] Specifically, one end of the boosting capacitor 12 is connected to terminal TCHP1, the other end of the boosting capacitor 12 is connected to terminal TCHP2, and the gate of the external transistor 11 is connected to terminal TDRV. The charge pump circuit 120 includes a drive circuit 160 and a gate control circuit 170. The drive circuit 160 outputs a drive signal CHP1 to one end of the boosting capacitor 12 based on the regulation voltage VRG. The gate control circuit 170 receives a signal CHP2 from the other end of the boosting capacitor 12. Based on the signal CHP2 and the source voltage VCO of the external transistor 11, the gate control circuit 170 outputs a gate control voltage DRV = VCO + VRG. This gate control voltage DRV is output to the gate of the external transistor 11 via terminal TDRV.

[0029] When the external transistor 11 is a P-type transistor, the source voltage of the external transistor 11 is the power supply voltage VCC. The charge pump circuit 120 can also output a gate control voltage DRV = VCC - VRG that is lower than the power supply voltage VCC by stepping down the regulation voltage VRG with respect to the power supply voltage VCC.

[0030] Charging circuit 180 charges the capacitance at node NLOAD of load 300 before external transistor 11 turns on. This reduces the inrush current when external transistor 11 turns on. The capacitance at node NLOAD of load 300 is, for example, a power supply stabilization capacitor connected to node NLOAD. Charging circuit 180 includes transistor 189, temperature sensor circuit 188, and control circuit 185.

[0031] The transistor 189 is provided between the power supply node NVCC and the node NLOAD. Specifically, the transistor 189 is a P-type transistor, the source of which is connected to the terminal TVCC, and the drain of which is connected to the terminal TVCO. The terminal TVCO is a terminal connected to the source of the external transistor 11 and the node NLOAD. Figure 1 Although the transistor 189 is shown as an example of a P-type transistor, the transistor 189 may be an N-type transistor.

[0032] The temperature sensor circuit 188 detects the temperature of the transistor 189, and outputs a temperature detection voltage VTA whose voltage value changes according to the detected temperature. The temperature sensor circuit 188 is disposed in the vicinity of the transistor 189 in a manner that enables detection of the temperature of the transistor 189. The temperature sensor circuit 188 is, for example, a temperature sensor that utilizes the temperature dependency of the forward voltage of a PN junction, but is not limited thereto, and can be various types of temperature sensors.

[0033] The control circuit 185 controls the transistor current by controlling the gate voltage GTA of the transistor 189. The transistor current in the charging circuit 180 is the current that flows through the transistor 189. The control circuit 185 controls the transistor current according to the temperature detection voltage VTA, and thereby prevents malfunction due to heating of the transistor 189. Further, the control circuit 185 controls so as to cause the transistor current to flow as much as possible within a range in which the transistor 189 can be maintained below the allowable temperature. Details of this control are described later.

[0034] The discharging circuit 190 discharges the capacitance of the node NLOAD of the load 300 after the external transistor 11 is turned off. Thereby, after the external transistor 11 is turned off, it is possible to prevent adverse situations caused by the voltage held in the capacitance of the node NLOAD or the charge accumulated in the capacitance of the node NLOAD. The discharging circuit 190 includes a transistor 199, a temperature sensor circuit 198, and a control circuit 195.

[0035] The transistor 199 is disposed between the node NLOAD and the ground node. Specifically, the transistor 199 is an N-type transistor, and the source is connected to the ground node, and the drain is connected to the terminal TDIS. The terminal TDIS is a terminal that is connected to the node NLOAD of the load 300.

[0036] The temperature sensor circuit 198 detects the temperature of the transistor 199, and outputs a temperature detection voltage VTB whose voltage value changes according to the detected temperature. The temperature sensor circuit 198 is disposed in the vicinity of the transistor 199 in a manner that enables detection of the temperature of the transistor 199. The temperature sensor circuit 198 is, for example, a temperature sensor that utilizes the temperature dependency of the forward voltage of a PN junction, but is not limited thereto, and can be various types of temperature sensors.

[0037] The control circuit 195 controls the transistor current by controlling the gate voltage GTB of the transistor 199. The transistor current in the discharge circuit 190 is the current flowing through the transistor 199. The control circuit 195 controls the transistor current in accordance with the temperature detection voltage VTB, thereby preventing malfunction due to heat generation of the transistor 199. Further, the control circuit 195 controls so as to flow the transistor current as much as possible within a range in which the transistor 199 can be maintained below the allowable temperature. Details of this control will be described later.

[0038] Figure 2 is a state transition diagram of the control by the control circuit 185 of the charge circuit 180 and the control circuit 195 of the discharge circuit 190. Hereinafter, the control by the control circuit 185 will be described as an example, but the same applies to the control by the control circuit 195. Further, hereinafter, an example in which the current value of the transistor current Itr is three, i.e., the first current value I1, the second current value I2, and the third current value I3, will be described, but the current value of the transistor current Itr can be four or more.

[0039] The second current value I2 is smaller than the first current value I1, and the third current value I3 is smaller than the second current value I2. When the first current value I1 is 100%, for example, the second current value I2 is 50% of I1, and the third current value I3 is 0% of I1. However, the current values are not limited thereto, as long as I1 > I2 > I3 is satisfied.

[0040] When the temperature TIC is detected to be lower than the second threshold TL before the first period WAIT1 elapses from the transition to the state SI2A, the control circuit 185 transitions to the state SI1. The second threshold TL is a temperature lower than the first threshold TH. The second threshold TL is set to a temperature at which the transistor current Itr can be maintained to some extent, for example, a temperature several degrees to several tens of degrees lower than the first threshold TH. In the state SI2A, the control circuit 185 does not determine whether the detected temperature TIC is the first threshold TH or more. The control circuit 185, when the first period WAIT1 elapses from the transition to the state SI2A, transitions to the state SI2B, and determines whether the detected temperature TIC is the first threshold TH or more and whether the detected temperature TIC is lower than the second threshold TL.

[0041] When the temperature TIC is detected to be lower than the second threshold TL before the first period WAIT1 elapses from the transition to the state SI2A, the control circuit 185 transitions to the state SI1. The second threshold TL is a temperature lower than the first threshold TH. The second threshold TL is set to a temperature at which the transistor current Itr can be maintained to some extent, for example, a temperature several degrees to several tens of degrees lower than the first threshold TH. In the state SI2A, the control circuit 185 does not determine whether the detected temperature TIC is the first threshold TH or more. The control circuit 185, when the first period WAIT1 elapses from the transition to the state SI2A, transitions to the state SI2B, and determines whether the detected temperature TIC is the first threshold TH or more and whether the detected temperature TIC is lower than the second threshold TL.

[0042] The control circuit 185 migrates to the state SI 1 when detecting that the temperature Tic becomes lower than the 2nd threshold value TL in the state SI2B. Further, the control circuit 185 migrates to the state SI3 when detecting that the temperature Tic becomes the 1st threshold value TH or more in the state SI2B, and sets the transistor current Itr to I3 which is lower than I2.

[0043] When migrating from the state SI 1 to the state SI2A, the transistor current Itr drops to I2, and thus the heat generation amount of the transistor 189 drops. At this time, there can be a case where the temperature of the transistor 189 turns to decrease and a case where it does not decrease. It is considered that the temperature of the transistor 189 temporarily exceeds the 1st threshold value TH when migrating from the state SI 1 to the state SI2A, and thus the 1st period WAIT1 is provided as a waiting time for waiting for the detection temperature Tic to be lower than the 1st threshold value TH in the case where it turns to decrease. On the other hand, in the case where the temperature of the transistor 189 does not decrease after migrating to the state SI2A, the state is migrated from the state SI2B to the state SI3 after the 1st period WAIT1 elapses, and the transistor current Itr drops to I3.

[0044] The control circuit 185 migrates to the state SI2C when detecting that the temperature Tic becomes lower than the 2nd threshold value TL in the state SI3, and sets the transistor current Itr to I2 which is larger than I3.

[0045] The control circuit 185 migrates to the state SI3 when detecting that the temperature Tic becomes the 1st threshold value TH or more before the 2nd period WAIT2 elapses from the migration to the state SI2C. The control circuit 185 does not determine whether the detection temperature Tic is lower than the 2nd threshold value TL in the state SI2C. The control circuit 185 migrates to the state SI2D when the 2nd period WAIT2 elapses from the migration to the state SI2C, and performs determination of whether the detection temperature Tic is the 1st threshold value TH or more and determination of whether the detection temperature Tic is lower than the 2nd threshold value TL.

[0046] The control circuit 185 migrates to the state SI 1 when detecting that the temperature Tic becomes lower than the 2nd threshold value TL in the state SI2D, and sets the transistor current Itr to I1 which is larger than I2.

[0047] When migrating from the state SI3 to the state SI2C, the transistor current Itr rises to I2, and thus the heat generation of the transistor 189 rises. At this time, there can be a case where the temperature of the transistor 189 turns to rise and a case where it does not. Since it is considered that the temperature of the transistor 189 temporarily falls below the second threshold TL when migrating from the state SI3 to the state SI2C, the second period WAIT2 is provided as a waiting time for waiting for the detection temperature TIC to exceed the second threshold TL in the case where the temperature turns to rise. On the other hand, in the case where the temperature of the transistor 189 does not rise after migrating to the state SI2C, the state is migrated from the state SI2D to the state SI1 after the second period WAIT2 elapses, and the transistor current Itr rises to I1.

[0048] The second period WAIT2 is longer than the first period WAIT1. Since the heat of the transistor 189 diffuses to the surroundings, it is conceivable that the speed of the temperature rise of the transistor 189 is slower than that of the temperature fall of the transistor 189. Therefore, the second period WAIT2 for waiting for the detection temperature TIC to exceed the second threshold TL is set to be longer than the first period WAIT1 for waiting for the detection temperature TIC to fall below the first threshold TH.

[0049] Figure 3 Fig. 1 is a first waveform chart illustrating the operation of the charging circuit 180. Here, an example of going back and forth between the states SI1 and SI2A is shown. Hereinafter, the operation of the charging circuit 180 is described as an example, but the same applies to the operation of the discharging circuit 190. In the charging, the voltage of the node NLOAD of the load 300 gradually rises as the charging progresses, and in the discharging, the voltage of the node NLOAD of the load 300 gradually falls as the discharging progresses.

[0050] When the charging control is started, the control circuit 185 moves to the state SI1, the transistor 189 flows the transistor current Itr = II, the transistor 189 generates heat, and the detection temperature Tic rises. When the detection temperature Tic reaches the 1st threshold TH, the control circuit 185 moves to the state SI2A, and the transistor current Itr decreases to I2. The amount of heat generated by the transistor 189 decreases, and the detection temperature Tic decreases. When the detection temperature Tic is lower than the 2nd threshold TL, the control circuit 185 moves to the state SI1, and the transistor current Itr increases to II. Hereinafter, the states SI1 and SI2A are repeated until the node NLOAD of the load 300 rises to the vicinity of the power supply voltage VCC. Thus, the temperature of the transistor 189 is maintained between the 1st threshold TH and the 2nd threshold TL. Thus, the temperature of the transistor 189 does not exceed the 1st threshold TH which is the allowable temperature, and therefore, the transistor 189 can be protected from overheating. Further, the transistor current is controlled so that the temperature of the transistor 189 is not lower than the 2nd threshold TL, and therefore, the transistor 189 can charge the capacitance of the node NLOAD of the load 300 with the largest possible transistor current.

[0051] When the node NLOAD reaches the vicinity of the power supply voltage VCC, the source-drain voltage of the transistor 189 decreases, the amount of heat generated by the transistor 189 decreases, and therefore, the state SI1 is maintained. When the capacitance of the node NLOAD is charged to the power supply voltage VCC, the transistor 189 no longer flows the current. Then, the control circuit 185 turns off the transistor 189, and the charge pump circuit 120 operates to turn on the external transistor 11.

[0052] Figure 4 Fig. 17 is a 2nd waveform chart illustrating the operation of the charging circuit 180. Hereinafter, the operation of the charging circuit 180 will be described as an example, and the operation of the discharging circuit 190 is the same. In the charging, the voltage of the node NLOAD of the load 300 gradually rises as the charging proceeds, and in the discharging, the voltage of the node NLOAD of the load 300 gradually decreases as the discharging proceeds.

[0053] When the charging control is started, the voltage of the node NLOAD of the load 300, that is, the source voltage VCO of the external transistor 11 is 0 V. Therefore, the source-drain voltage of the transistor 189 becomes the power supply voltage VCC, and in the state SI1, the amount of heat generated when the transistor current Itr = II flows is large, and the temperature of the transistor 189 rises in a short time, the state moves to SI2A, and the transistor current Itr becomes I2. Immediately after the charging is started, the temperature of the surroundings of the transistor 189 does not rise, and therefore, the heat of the transistor 189 easily spreads to the surroundings, and therefore, the temperature of the transistor 189 decreases, the state moves to SI1, and the transistor current Itr becomes II.

[0054] During the period in which this operation is repeated, the temperature around the transistor 189 rises, and therefore heat from the transistor 189 is not easily diffused to the surroundings, and the temperature of the transistor 189 does not easily fall. Thus, the state remains in SI2A, and after the first period WAIT1 elapses in the state SI2A, the state moves to SI2B. When it is determined that the detected temperature Tic is equal to or higher than the first threshold value TH in the state SI2B, the state moves to SI3, and the transistor current Itr becomes I3. The transistor current Itr falls, and therefore the temperature of the transistor 189 falls and the state moves to SI2C, and the transistor current Itr becomes I2. Hereinafter, the state is alternated between SI3 and SI2C.

[0055] The node NLOAD of the load 300 is charged by the transistor current Itr, and therefore the source voltage VCO of the external transistor 11 rises. Thus, the voltage between the source and the drain of the external transistor 11 falls, and therefore the amount of heat generated by the transistor 189 falls, and the time during which the state remains in SI2C extends. After the second period WAIT2 elapses in the state SI2C, the state moves to SI2D. When it is determined that the detected temperature Tic is lower than the second threshold value TL in the state SI2D, the state moves to SI1, and the transistor current Itr becomes I1. The transistor current Itr increases, and therefore the temperature of the transistor 189 rises and the state moves to SI2A, and the transistor current Itr becomes I2.

[0056] During the period in which this operation is repeated, the source voltage VCO further rises, and therefore the voltage between the source and the drain of the external transistor 11 falls, and the amount of heat generated by the transistor 189 falls. Thus, the state remains in SI1, and when the node NLOAD of the load 300 is charged to the power supply voltage VCC, no current flows in the transistor 189. Then, the transistor 189 is turned off, and the external transistor 11 is turned on.

[0057] In the above embodiment, the circuit device 100 includes a control circuit 185 that controls the transistor current in accordance with a detected temperature. The detected temperature is a temperature detected by a temperature sensor circuit 188 that detects the temperature of the transistor 189. The transistor 189 charges a load 300 supplied with a power supply voltage VCC. The transistor current is a current that flows in the transistor 189 during the charging. The control circuit 185 decreases the transistor current when the detected temperature is higher than a first threshold value TH, and increases the transistor current when the detected temperature is lower than a second threshold value TL that is lower than the first threshold value TH.

[0058] According to the present embodiment, when the detected temperature becomes higher than the first threshold value TH, the transistor current decreases, and thus the temperature of the transistor 189 decreases. Thereby, the transistor 189 can be protected from overheating. Further, when the detected temperature becomes lower than the second threshold value TL, the transistor current increases, and thus the transistor current is controlled in a range in which the detected temperature reaches the first threshold value TH from the second threshold value TL. Thereby, in a range not exceeding the first threshold value TH as the allowable temperature, the transistor 189 can charge the capacitance of the node NLOAD of the load 300 with the largest possible transistor current.

[0059] In Figure 1 the present embodiment, an example in which the transistor 189 and the temperature sensor circuit 188 are provided inside the circuit device 100 is described, but the present embodiment is not limited thereto. The transistor 189 and the temperature sensor circuit 188 can be provided outside the circuit device 100.

[0060] In the above-described present embodiment, the circuit device 100 includes the control circuit 195 that controls the transistor current in accordance with the detected temperature. The detected temperature is a temperature detected by the temperature sensor circuit 198 that detects the temperature of the transistor 199. The transistor 199 discharges from the load 300 to which the power supply voltage VCC is supplied. The transistor current is a current that flows through the transistor 199 in the discharge. The control circuit 195 decreases the transistor current when the detected temperature is higher than the first threshold value TH, and increases the transistor current when the detected temperature is lower than the second threshold value TL that is lower than the first threshold value TH.

[0061] According to the present embodiment, when the detected temperature becomes higher than the first threshold value TH, the transistor current decreases, and thus the temperature of the transistor 199 decreases. Thereby, the transistor 199 can be protected from overheating. Further, when the detected temperature becomes lower than the second threshold value TL, the transistor current increases, and thus the transistor current is controlled in a range in which the detected temperature reaches the first threshold value TH from the second threshold value TL. Thereby, in a range not exceeding the first threshold value TH as the allowable temperature, the transistor 199 can discharge the capacitance of the node NLOAD of the load 300 with the largest possible transistor current.

[0062] In Figure 1 the present embodiment, an example in which the transistor 199 and the temperature sensor circuit 198 are provided inside the circuit device 100 is described, but the present embodiment is not limited thereto. The transistor 199 and the temperature sensor circuit 198 can be provided outside the circuit device 100.

[0063] In Figure 1 the present embodiment, an example in which the circuit device 100 includes both the charging circuit 180 and the discharging circuit 190 is described, but the circuit device 100 can include only either one of the charging circuit 180 or the discharging circuit 190.

[0064] The following description will be made using the control circuit 185 as an example, and the same applies to the control circuit 195 .

[0065] In this embodiment, the control circuit 185 controls the transistor current to be set to the first current value I1, the second current value I2 smaller than the first current value I1, or the third current value I3 smaller than the second current value I2. When the transistor current is the second current value I2 and the detected temperature is higher than the first threshold value TH, the control circuit 185 controls the transistor current to be set to the third current value I3. Figure 3 In the example of , this control corresponds to the transition from SI2B to SI3 or the transition from SI2C to SI3. When the transistor current is the second current value I2 and the detected temperature is lower than the second threshold TL, the control circuit 185 controls the transistor current to be set to the first current value I1. Figure 3 In the example of , this control corresponds to the transition from SI2A to SI1 or the transition from SI2D to SI1.

[0066] According to this embodiment, when the detected temperature is higher than the first threshold value TH, the control circuit 185 changes the transistor current from the second current value I2 to the third current value I3, thereby reducing the transistor current. Furthermore, when the detected temperature is higher than the second threshold value TL, the control circuit 185 changes the transistor current from the second current value I2 to the first current value I1, thereby increasing the transistor current.

[0067] In addition, in this embodiment, the control circuit 185 performs control to set the transistor current to the second current value I2 when the transistor current is the first current value I1 and the detected temperature is higher than the first threshold value TH. Figure 3 In the example, this control corresponds to the transition from SI1 to SI2A. After the first period WAIT1 has elapsed since the transistor current was set to the second current value I2, the control circuit 185 determines whether the detected temperature is higher than the first threshold value TH. If it is determined that the detected temperature is higher than the first threshold value TH, the transistor current is set to the third current value I3. Figure 3 In the example, the control corresponds to the transition from SI2A to SI2B and the transition from SI2B to SI3.

[0068] In the case where the transistor current is the first current value I1 and the detection temperature exceeds the first threshold value TH, the transistor current becomes the second current value I2, and it can be considered that the detection temperature temporarily exceeds the first threshold value TH at this time. In the case where the first period WAIT1 is not provided, the detection temperature exceeds the first threshold value TH, and thus the transistor current is changed from the second current value I2 to the third current value I3. That is, the transistor current is further decreased to the third current value I3, although there is a possibility that the temperature decreases due to the decrease of the transistor current to the second current value I2. In this regard, according to the present embodiment, the first period WAIT1 is provided to wait until the temperature is lower than the first threshold value TH in the case where the temperature decreases after the transistor current is decreased to the second current value I2, and thus the transistor current is not decreased to the third current value I3. Thus, it is possible to cause the transistor current to shift between two states, i.e., between the first current value I1 and the second current value I2.

[0069] Further, in the present embodiment, the control circuit 185 performs control to set the transistor current to the second current value I2 when the transistor current is the third current value I3 and the detection temperature is lower than the second threshold value TL. Figure 3 In the example of FIG. 6, this control corresponds to the shift from SI3 to SI2C. The control circuit 185 determines whether the detection temperature is lower than the second threshold value TL after the second period WAIT2 elapses from the setting of the transistor current to the second current value I2, and performs control to set the transistor current to the first current value I1 when it is determined that the detection temperature is lower than the second threshold value TL. Figure 3 In the example of FIG. 6, this control corresponds to the shift from SI2C to SI2D and the shift from SI2D to SIl.

[0070] In the case where the transistor current is the third current value I3 and the detection temperature is lower than the second threshold value TL, the transistor current becomes the second current value I2, and it can be considered that the detection temperature temporarily becomes lower than the second threshold value TL at this time. In the case where the second period WAIT2 is not provided, the detection temperature is lower than the second threshold value TL, and thus the transistor current is changed from the second current value I2 to the first current value I1. That is, the transistor current is further increased to the first current value I1, although there is a possibility that the temperature increases due to the increase of the transistor current to the second current value I2. In this regard, according to the present embodiment, the second period WAIT2 is provided to wait until the temperature exceeds the second threshold value TL in the case where the temperature increases after the transistor current is increased to the second current value I2, and thus the transistor current is not increased to the first current value I1. Thus, it is possible to cause the transistor current to shift between two states, i.e., between the third current value I3 and the second current value I2.

[0071] Further, in the present embodiment, the length of the second period WAIT2 is longer than the length of the first period WAIT1.

[0072] Since heat of the transistor 189 spreads to the surroundings, it is conceivable that the speed of temperature rise of the transistor 189 is slower than the speed of temperature drop of the transistor 189. Therefore, by setting the second period WAIT2 for waiting for the detection temperature to exceed the second threshold value TL to be longer than the first period WAIT1 for waiting for the detection temperature to be lower than the first threshold value TH, appropriate waiting control can be achieved.

[0073] Further, in the present embodiment, the transistor 189 is connected in parallel with the external transistor 11 provided between the node NVCC of the power supply voltage VCC and the node NLOAD of the load 300. The transistor 189 performs charging of the load 300 before the external transistor 11 is turned on.

[0074] The transistor 189 is connected in parallel with the external transistor 11, whereby the capacitance of the node NLOAD of the load 300 can be charged by the transistor current of the transistor 189 before the external transistor 11 is turned on. According to the present embodiment, protection of the transistor 189 from overheating and charging as fast as possible within the range of the protection can be achieved at the same time.

[0075] Further, in the present embodiment, the transistor 199 is provided between the node NLOAD of the load 300 and the ground node. The transistor 199 discharges from the load 300 after the external transistor 11 is turned off.

[0076] The transistor 199 is provided between the node NLOAD of the load 300 and the ground node, whereby the capacitance of the node NLOAD of the load 300 can be discharged by the transistor current of the transistor 199 after the external transistor 11 is turned off. According to the present embodiment, protection of the transistor 199 from overheating and discharging as fast as possible within the range of the protection can be achieved at the same time.

[0077] 2. Detailed configuration example

[0078] Figure 5 is a detailed configuration example of the charging circuit 180. The charging circuit 180 includes the transistor 189, the temperature sensor circuit 188, the control circuit 185, and the reference voltage generation circuit 140.

[0079] The reference voltage generating circuit 140 generates a first reference voltage VH, a second reference voltage VL, and a third reference voltage VTSD. The first reference voltage VH is a voltage corresponding to the first threshold value TH, and is a voltage value identical to the temperature detection voltage VTA when the detection temperature TIC is the first threshold value TH. The second reference voltage VL is a voltage corresponding to the second threshold value TL, and is a voltage value identical to the temperature detection voltage VTA when the detection temperature TIC is the second threshold value TL. The third reference voltage VTSD is a voltage corresponding to the third threshold value Tmax, and is a voltage value identical to the temperature detection voltage VTA when the detection temperature TIC is the third threshold value Tmax. As shown in FIG. 8, the third threshold value Tmax is a temperature higher than the first threshold value TH, and corresponds to the allowable upper limit temperature of the circuit device 100. Figure 3

[0080] The control circuit 185 includes a high-temperature-side temperature detection circuit 181, a low-temperature-side temperature detection circuit 182, a protection temperature detection circuit 183, a state control circuit 186, and a constant current control circuit 187.

[0081] The high-temperature-side temperature detection circuit 181 detects whether the temperature detection voltage VTA is higher than the first reference voltage VH, and outputs a detection signal THDA thereof.

[0082] The low-temperature-side temperature detection circuit 182 detects whether the temperature detection voltage VTA is lower than the second reference voltage VL, and outputs a detection signal TLDA thereof.

[0083] The protection temperature detection circuit 183 detects whether the temperature detection voltage VTA is higher than the third reference voltage VTSD, and detects whether the temperature detection voltage VTA is lower than a fourth reference voltage Vmin after the temperature detection voltage VTA exceeds the third reference voltage VTSD, and outputs a detection signal TSDDA thereof. The fourth reference voltage Vmin is a voltage corresponding to a fourth threshold value Tmin. As shown in FIG. 8, the fourth threshold value Tmin is a voltage lower than the second threshold value TL. Figure 3

[0084] The state control circuit 186 performs Figure 2 the control described above in accordance with the detection signals THDA and TLDA. At this time, the state control circuit 186 outputs a current setting signal CNTA for setting the current value of the transistor current to the constant current control circuit 187. The constant current control circuit 187 controls the transistor current to the current value indicated by the current setting signal CNTA by outputting a gate voltage GTA corresponding to the current value indicated by the current setting signal CNTA to the gate of the transistor 189. Further, the state control circuit 186 includes a timer TMA, and performs the waiting control of the first period WAIT1 in the state SI2A and the waiting control of the second period WAIT2 in the state SI2C using the timer TMA. ​​

[0085] Further, the state control circuit 186 stops the control when the detection signal TSDDA indicating that the temperature of the transistor 189 exceeds the third threshold Tmax is input, and outputs a current setting signal CNTA that causes the transistor 189 to be turned off. Then, the state control circuit 186 resumes the control when the detection signal TSDDA indicating that the temperature of the transistor 189 is lower than the fourth threshold Tmin is input. Figure 2 Figure 2

[0086] Further, the circuit device 100 becomes the shutdown state when the protection temperature detection circuit 183 outputs the detection signal TSDDA indicating that the temperature of the transistor 189 exceeds the third threshold Tmax. Then, the circuit device 100 cancels the shutdown state when the protection temperature detection circuit 183 outputs the detection signal TSDDA indicating that the temperature of the transistor 189 is lower than the fourth threshold Tmin.

[0087] Figure 6 is a detailed configuration example of the discharging circuit 190. The discharging circuit 190 includes a transistor 199, a temperature sensor circuit 198, and a control circuit 195. Figure 6 The example in which the common reference voltage generation circuit 140 is provided with respect to the charging circuit 180 and the discharging circuit 190 is shown. However, the reference voltage generation circuit can be separately provided with respect to the charging circuit 180 and the discharging circuit 190.

[0088] The control circuit 195 includes a high-temperature-side temperature detection circuit 191, a low-temperature-side temperature detection circuit 192, a protection temperature detection circuit 193, a state control circuit 196, and a constant current control circuit 197.

[0089] The high-temperature-side temperature detection circuit 191 detects whether the temperature detection voltage VTB is higher than the first reference voltage VH, and outputs a detection signal THDB thereof.

[0090] The low-temperature-side temperature detection circuit 192 detects whether the temperature detection voltage VTB is lower than the second reference voltage VL, and outputs a detection signal TLDB thereof.

[0091] The protection temperature detection circuit 193 detects whether the temperature detection voltage VTB is higher than the third reference voltage VTSD, and detects whether the temperature detection voltage VTB is lower than the fourth reference voltage Vmin after the temperature detection voltage VTB exceeds the third reference voltage VTSD, and outputs a detection signal TSDDB thereof.

[0092] The state control circuit 196 performs the control in accordance with the detection signals THDB and TLDB, and the detection signal TSDDB. Figure 2 ​​The same control. At this time, the state control circuit 196 outputs a current setting signal CNTB that sets the current value of the transistor current to the constant current control circuit 197. The constant current control circuit 197 controls the transistor current to the current value indicated by the current setting signal CNTB by outputting a gate voltage GTB corresponding to the current value indicated by the current setting signal CNTB to the gate of the transistor 199. Further, the state control circuit 196 includes a timer TMB, and uses the timer TMB to perform the waiting control of the first period WAIT1 in the state SI2A and the waiting control of the second period WAIT2 in the state SI2C.

[0093] Further, the state control circuit 196 stops the control of the transistor 199 when a detection signal TSDDB indicating that the temperature of the transistor 199 exceeds the third threshold Tmax is input, and outputs a current setting signal CNTB that causes the transistor 199 to be turned off. Then, the state control circuit 196 resumes the control of the transistor 199 when a detection signal TSDDB indicating that the temperature of the transistor 199 is lower than the fourth threshold Tmin is input. Figure 2 Figure 2

[0094] Further, the circuit device 100 becomes the shutdown state when the protection temperature detection circuit 193 outputs the detection signal TSDDB indicating that the temperature of the transistor 199 exceeds the third threshold Tmax. Then, the circuit device 100 cancels the shutdown state when the protection temperature detection circuit 193 outputs the detection signal TSDDB indicating that the temperature of the transistor 199 is lower than the fourth threshold Tmin.

[0095] Figure 7 is a detailed configuration example of the constant current control circuit 187. Further, the constant current control circuit 197 is also the same configuration. The constant current control circuit 187 includes a current source IBG and transistors TRG1 to TRG6.

[0096] The transistors TRG6, TRG3, and TRG4 are N-type transistors, and constitute a current mirror circuit. The current output from the current source IBG flows through the transistor TRG6, and this current is mirrored to currents flowing through the transistors TRG3 and TRG4. Let the mirrored current be I0.

[0097] ​​The transistors TRGl, TRG2 are N-type transistors. The transistor TRGl is connected in series with the transistor TRG3, and when the transistor TRGl is turned on, the current IO flows through the transistor TRG3. The transistor TRG2 is connected in series with the transistor TRG4, and when the transistor TRG2 is turned on, the current IO flows through the transistor TRG4. A signal CNTl is input to the gate of the transistor TRGl from the control circuit 185, and the transistor TRGl is turned off when CNTl = 0 and turned on when CNTl = 1. A signal CNT2 is input to the gate of the transistor TRG2 from the control circuit 185, and the transistor TRG2 is turned off when CNT2 = 0 and turned on when CNT2 = 1. The signals CNTl, CNT2 correspond to the current setting signal CNTA of Figure 5

[0098] The transistor TRG5 is a P-type transistor. The current flowing through the transistors TRG3, TRG4 flows through the transistor TRG5, and this current is mirrored as a transistor current Itr flowing through the transistor 189. The transistor current becomes Itr = IO x (CNTl + CNT2), and can take three states of Itr = 0, IO, 2 x IO. In this example, Figure 2 Ii, I2, I3 are 0, IO, 2 x IO.

[0099] Figure 8 is a detailed configuration example of the temperature sensor circuit 188, the reference voltage generating circuit 140, the high-temperature-side temperature detection circuit 181, the low-temperature-side temperature detection circuit 182, and the protection temperature detection circuit 183. Also, the high-temperature-side temperature detection circuit 191, the low-temperature-side temperature detection circuit 192, and the protection temperature detection circuit 193 are the same configuration.

[0100] The temperature sensor circuit 188 includes a current source IBF and diodes DF1, DF2. The current output from the current source IBF flows through the diodes DF1, DF2 connected in series, and as a result, a voltage of twice the forward voltage of the diodes is generated at the anode of the diode DF1. This voltage is the temperature detection voltage VTA.

[0101] The reference voltage generating circuit 140 includes a first ladder resistance circuit composed of resistors RF3 to RF5 and a second ladder resistance circuit composed of resistors RF1, RF2. The first ladder resistance circuit generates a first reference voltage VH and a second reference voltage VL by dividing the reference voltage VREF. The second ladder resistance circuit generates a third reference voltage VTSD by dividing the reference voltage VREF.

[0102] ​The high-temperature-side temperature detection circuit 181 is a comparator that compares the temperature detection voltage VTA with the first reference voltage VH. The comparator outputs a low-level detection signal THDA when VTA > VH, and outputs a high-level detection signal THDA when VTA < VH.

[0103] The low-temperature-side temperature detection circuit 182 is a comparator that compares the temperature detection voltage VTA with the second reference voltage VL. The comparator outputs a low-level detection signal TLDA when VTA > VL, and outputs a high-level detection signal TLDA when VTA < VL.

[0104] The protection temperature detection circuit 183 is a hysteresis comparator that compares the temperature detection voltage VTA with the third reference voltage VTSD. The hysteresis comparator makes the detection signal TSDDA go from high level to low level if VTA > VTSD when the detection signal TSDDA is high level. In addition, the hysteresis comparator makes the detection signal TSDDA go from low level to high level if VTA < VTSD when the detection signal TSDDA is low level.

[0105] Figure 9 is a detailed configuration example of the drive circuit 160 and the gate control circuit 170 that constitute the charge pump circuit 120.

[0106] The drive circuit 160 includes a first transistor TRA1, a second transistor TRA2, and a charge pump control circuit 162. The first transistor TRA1 is a P-type transistor, and its source is connected to the output node NVRG of the regulator 110, and its drain is connected to the terminal TCHP1. The second transistor TRA2 is an N-type transistor, and its source is connected to a ground node, and its drain is connected to the terminal TCHP1.

[0107] The gate control circuit 170 includes a first diode DI1, a second diode DI2, and a resistor RB. The anode of the first diode DI1 is connected to the terminal TCHP2, and the cathode is connected to the terminal TDRV. The anode of the second diode DI2 is connected to the terminal TVCO, and the cathode is connected to the terminal TCHP2. The first diode DI1 and the second diode DI2 are, for example, Schottky barrier diodes. One end of the resistor RB is connected to the cathode of the first diode DI1 and the terminal TDRV, and the other end is connected to the anode of the second diode DI2 and the terminal TVCO.

[0108] The operation of the charge pump circuit 120 will be described. Hereinafter, the forward voltages of the first diode DI1 and the second diode DI2 will be ignored.

[0109] The charge pump control circuit 162 alternately turns on the first transistor TRA1 and the second transistor TRA2. When the first transistor TRA1 is turned off and the second transistor TRA2 is turned on, the drive signal CHP1 is 0 V. At this time, the signal CHP2 becomes the same voltage as the source voltage VCO through the second diode DI2. When the first transistor TRA1 is turned on from being turned off and the second transistor TRA2 is turned off from being turned on, the drive signal CHP1 rises from 0 V to the regulation voltage VRG. Thus, the signal CHP2 becomes a voltage higher than the source voltage VCO by the regulation voltage VRG.

[0110] The voltage VCO+VRG is the gate control voltage DRV, which is output to the gate of the external transistor 11 via the first diode DI1. The gate of the external transistor 11 is charged by the charge supplied from the drive circuit 160, and in a steady state, the gate control voltage DRV is maintained at VCO+VRG.

[0111] When the charge pump circuit 120 is stopped, the charge pump control circuit 162 does not drive the first transistor TRA1 and the second transistor TRA2. For example, the charge pump control circuit 162 maintains the first transistor TRA1 on and the second transistor TRA2 off. After the charge pump circuit 120 is stopped, the voltage between the gate and the source of the external transistor 11 is made 0 V by the resistor RB.

[0112] The circuit device of the above-described embodiment includes a control circuit that controls a transistor current flowing through a transistor in charging, in accordance with a detected temperature detected by a temperature sensor circuit that detects a temperature of the transistor that charges a load supplied with a power supply voltage. The control circuit decreases the transistor current when the detected temperature is higher than a first threshold value, and increases the transistor current when the detected temperature is lower than a second threshold value that is lower than the first threshold value.

[0113] According to the embodiment, since the transistor current is decreased when the detected temperature is higher than the first threshold value, the temperature of the transistor decreases. Thus, the transistor can be protected from overheating. Further, since the transistor current is increased when the detected temperature becomes lower than the second threshold value, the transistor current is controlled in such a manner that the detected temperature reaches the first threshold value from the second threshold value. Thus, in a range not exceeding the first threshold value as an allowable temperature, the transistor can charge the capacitance of the node of the load with the largest possible transistor current.

[0114] Further, the circuit device of the present embodiment includes a control circuit that controls a transistor current flowing through the transistor in the discharging in accordance with a detected temperature detected by a temperature sensor circuit that detects a temperature of the transistor discharging from the load supplied with the power supply voltage. The control circuit decreases the transistor current when the detected temperature is higher than a first threshold value, and increases the transistor current when the detected temperature is lower than a second threshold value lower than the first threshold value.

[0115] According to the present embodiment, when the detected temperature is higher than the first threshold value, the transistor current is decreased, and thus the temperature of the transistor is decreased. Thereby, the transistor can be protected from overheating. Further, since the transistor current is increased when the detected temperature becomes lower than the second threshold value, the transistor current is controlled in such a manner that the detected temperature reaches the first threshold value from the second threshold value. Thereby, in a range not exceeding the first threshold value as the allowable temperature, the transistor can discharge from the capacitance of the node of the load with the largest possible transistor current.

[0116] Further, in the present embodiment, it can be that the control circuit performs control to set the transistor current to a first current value, a second current value smaller than the first current value, or a third current value smaller than the second current value. It can be that the control circuit performs control to set the transistor current to the third current value when the transistor current is the second current value and the detected temperature is higher than the first threshold value. It can be that the control circuit performs control to set the transistor current to the first current value when the transistor current is the second current value and the detected temperature is lower than the second threshold value.

[0117] According to the present embodiment, when the detected temperature is higher than the first threshold value, the control circuit changes the transistor current from the second current value to the third current value, and thus the transistor current can be decreased. Further, when the detected temperature is lower than the second threshold value, the control circuit changes the transistor current from the second current value to the first current value, and thus the transistor current can be increased.

[0118] Further, in the present embodiment, it can be that the control circuit performs control to set the transistor current to the second current value when the transistor current is the first current value and the detected temperature is higher than the first threshold value. It can be that the control circuit performs determination whether the detected temperature is higher than the first threshold value after a first period elapses from the control to set the transistor current to the second current value, and sets the transistor current to the third current value when it is determined that the detected temperature is higher than the first threshold value.

[0119] According to the present embodiment, in a case where the transistor current decreases to the second current value and then the temperature decreases, since the first period for waiting until the temperature is lower than the first threshold value is provided, the transistor current does not decrease to the third current value. Thus, in a state where the temperature decreases while the transistor current is the second current value, the transistor current can be shifted between the two states, i.e., between the first current value and the second current value.

[0120] Further, in the present embodiment, it can also be that the control circuit performs control to set the transistor current to the second current value when the transistor current is the third current value and the detected temperature is lower than the second threshold value. It can also be that the control circuit performs determination as to whether the detected temperature is lower than the second threshold value after the second period elapses from when the transistor current is set to the second current value, and performs control to set the transistor current to the first current value when it is determined that the detected temperature is lower than the second threshold value.

[0121] According to the present embodiment, in a case where the transistor current increases to the second current value and then the temperature increases, since the second period for waiting until the temperature exceeds the second threshold value is provided, the transistor current does not increase to the first current value. Thus, in a state where the temperature increases while the transistor current is the second current value, the transistor current can be shifted between the two states, i.e., between the third current value and the second current value.

[0122] Further, in the present embodiment, it can also be that the length of the second period is longer than the length of the first period.

[0123] Since heat of the transistor diffuses to the surroundings, it is conceivable that the speed of temperature increase of the transistor is slower than the speed of temperature decrease of the transistor. Thus, by setting the second period for waiting until the detected temperature exceeds the second threshold value to be longer than the first period for waiting until the detected temperature is lower than the first threshold value, appropriate waiting control can be achieved.

[0124] Further, in the present embodiment, it can also be that the transistor is connected in parallel with an external transistor provided between a node of the power supply voltage and a node of the load. It can also be that the transistor performs charging of the load before the external transistor is turned on.

[0125] The transistor is connected in parallel with the external transistor, whereby the load can be charged by the transistor current of the transistor before the external transistor is turned on. According to the present embodiment, it is possible to simultaneously achieve protection of the transistor from overheating and charging at the highest possible speed within the range of the protection.

[0126] Further, in the present embodiment, the transistor can also be provided between the node of the load and the ground node. The transistor can also discharge from the load after the external transistor is turned off, provided between the node of the power supply voltage and the node of the load.

[0127] The transistor is provided between the node of the load and the ground node, whereby the load can be discharged by the transistor current of the transistor after the external transistor is turned off. According to the present embodiment, it is possible to simultaneously achieve protection of the transistor from overheating and discharge as fast as possible within the range that can be protected.

[0128] Further, the circuit device of the present embodiment can also include the transistor and the temperature sensor circuit.

[0129] In addition, although the present embodiment has been described in detail as above, those skilled in the art will be able to easily understand various modifications that can be made without departing substantially from the present application, and the effects. Therefore, such modified examples are all included in the scope of the present application, for example, the language recited at least once in the specification or drawings together with a more general or synonymous different language can be replaced with the different language at any place in the specification or drawings. Further, all combinations of the present embodiment and the modified examples are also included in the scope of the present application. Further, the structure and the operation of the charging circuit, the discharging circuit, the regulator, the charge pump circuit, the circuit device, the load, the electronic device, and the like are not limited to those described in the present embodiment, and various modifications can be made.

Claims

1. A circuit device, characterized in that: The circuit device includes a control circuit that controls a transistor current flowing through a transistor during charging based on a temperature detected by a temperature sensor circuit, wherein the temperature sensor detects the temperature of the transistor that charges an external load to which a power supply voltage is supplied. The control circuit controls the transistor current to be set to a first current value, a second current value smaller than the first current value, or a third current value smaller than the second current value. The control circuit performs control to set the transistor current to the second current value when the transistor current is the first current value and the detected temperature is higher than a first threshold value. The control circuit controls the transistor current to be set to the third current value when the transistor current is the second current value and the detected temperature is higher than the first threshold value, and controls the transistor current to be set to the first current value when the transistor current is the second current value and the detected temperature is lower than a second threshold value that is lower than the first threshold value. The transistor is connected in parallel with an external transistor, and the external transistor is provided between a node of the power supply voltage and a node of the load, The transistor charges the load before the external transistor is turned on.

2. A circuit device, characterized in that: The circuit device includes a control circuit that controls a transistor current flowing through a transistor during discharge based on a temperature detected by a temperature sensor circuit, wherein the temperature sensor detects a temperature of the transistor that performs the discharge from an external load to which a power supply voltage is supplied. The control circuit controls the transistor current to be set to a first current value, a second current value smaller than the first current value, or a third current value smaller than the second current value. The control circuit performs control to set the transistor current to the second current value when the transistor current is the first current value and the detected temperature is higher than a first threshold value. The control circuit controls the transistor current to be set to the third current value when the transistor current is the second current value and the detected temperature is higher than the first threshold value, and controls the transistor current to be set to the first current value when the transistor current is the second current value and the detected temperature is lower than a second threshold value that is lower than the first threshold value. The transistor is arranged between the node of the load and the ground node, The transistor performs the discharge from the load after an external transistor provided between the node of the power supply voltage and a node of the load is turned off.

3. The circuit arrangement according to claim 1 or 2, characterized in that The control circuit determines whether the detected temperature is higher than the first threshold value after a first period has passed since the transistor current was set to the second current value, and sets the transistor current to the third current value if it is determined that the detected temperature is higher than the first threshold value.

4. The circuit arrangement according to claim 3, characterized in that The control circuit controls the transistor current to be set to the second current value when the transistor current is the third current value and the detected temperature is lower than the second threshold value. After a second period has passed since the transistor current was set to the second current value, the control circuit determines whether the detected temperature is lower than the second threshold value. When it is determined that the detected temperature is lower than the second threshold value, the control circuit controls the transistor current to be set to the first current value.

5. The circuit arrangement according to claim 4, characterized in that The length of the second period is longer than the length of the first period.

6. The circuit arrangement according to claim 1 or 2, characterized in that The circuit device comprises: the transistor; and The temperature sensor circuit.

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