JP2009240112A - Power supply device and semiconductor integrated circuit device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stable power source by improving the fluctuation of an output voltage in light load in a switching regulator. <P>SOLUTION: A comparator 12 compares a current instruction value of an error amplifier 11 with a reference voltage STOPREF. When the current instruction value becomes lower than the reference value STOPREF, a Hi-level signal is output to carry out the PWM control. When the current instruction value becomes higher than the reference value STOPREF, a Lo-level signal is output to stop the PWM control by stopping the switching operation of a transistor 10. In light load having a small load current amount, the ON timing of the transistor 10 is controlled by the current instruction value, so that switching control suppressing ripples of an output voltage Vo is performed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a voltage stabilization technique for a switching regulator, and more particularly to a technique that is effective in reducing output voltage fluctuations at light loads.

  Switching regulators are widely used in semiconductor integrated circuit devices. This type of switching regulator is required to have high efficiency, and a switching regulator used in a semiconductor integrated circuit device for portable devices is required to have high efficiency at the time of light load during standby or the like.

  For this reason, switching regulators use PWM (Pulse Width Modulation) control to improve efficiency at light loads, and control the pulse output timing by keeping the switching pulse width constant at light loads. A technique for performing PFM (Pulse Frequency Modulation) control is known.

  Also, switching between PWM control and PFM control is known by monitoring the output current of the switching regulator. During PFM control, the output voltage is monitored to determine the ON timing of the PFM control driver. is doing.

Further, in this type of switching regulator, for example, an oscillation circuit that determines an ON timing in PWM mode control, a comparison voltage source that determines an ON time in PFM control mode, a voltage of the comparison voltage source, and an error amplification circuit There is a multiplexer that outputs either one of the output voltages, and in each control mode, a voltage that is input to the comparison circuit is switched over to determine the on-time in the PWM control mode and the on-time in the PFM control mode. Yes (see Patent Document 1).
JP 2007-259599 A

  However, the present inventors have found that the above-described efficiency improvement technology at light load in the switching regulator has the following problems.

  That is, in the PFM control, the output voltage is monitored, the PFM operation is performed when the output voltage falls below an arbitrary threshold value, and the PFM operation is stopped when the output voltage is higher than the arbitrary threshold value. Since the control is performed, there is a problem that the ripple of the output voltage becomes large.

  Further, when a large current is required from a light load such as a standby time, the PFM control is shifted to the PWM control. However, since the PFM control cannot follow a large load fluctuation, the PFM control is performed. When switching from control to PWM control, there is a problem that the fluctuation of the output voltage becomes large.

  Further, since a circuit for PWM control and a circuit for PFM control are required, there is a problem that the circuit scale of the switching regulator is increased, which hinders miniaturization of the semiconductor integrated circuit device.

  An object of the present invention is to provide a technique capable of improving a fluctuation in output voltage at a light load in a switching regulator and providing a stable power supply.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in the present application, the outline of typical ones will be briefly described as follows.

  The present invention is a power supply device that converts a DC power supply voltage into an arbitrary DC voltage, and based on a PWM signal, a driver unit that performs switching, and a current instruction value that indicates an output current output from the power supply device. An output current indicating unit to be generated, and an operation control unit that controls output of a PWM signal to be supplied to the driver unit based on a current instruction value output from the output current indicating unit. The PWM signal is output when the indicated value is larger than an arbitrary threshold voltage, and the output of the PWM signal is stopped when the current indicated value is smaller than the arbitrary threshold voltage.

  Further, in the present invention, the output current instruction unit includes an error amplifier that outputs an error amount between an output voltage of the power supply device and a reference voltage as a current instruction value, and the operation control unit includes a current output from the error amplifier. Comparing the indicated value with the threshold voltage and comparing whether the current indicated value is larger than the threshold voltage or not, the current indicated value output from the error amplifier and the output current of the power supply device are compared. Based on the comparison result, a hysteresis comparator that generates and outputs a PWM signal for driving the driver unit, and a PWM signal generated by the hysteresis comparator when the comparator determines that the current instruction value is larger than the threshold voltage When the comparator determines that the current indication value is smaller than the threshold voltage, the output of the PWM signal generated by the hysteresis comparator is stopped. In which more the output judging unit for.

  Further, according to the present invention, the power supply device comprises an output current feedback type switching regulator.

  Moreover, the outline | summary of the other invention of this application is shown briefly.

  The present invention is a semiconductor integrated circuit device including a voltage generation control unit used in a power supply device that converts a DC power supply voltage into an arbitrary DC voltage, and the voltage generation control unit performs switching based on a PWM signal. A pre-driver that drives the driver to perform, an output current instruction unit that generates a current instruction value indicating an output current output from the power supply device, and a pre-driver based on the current instruction value output from the output current instruction unit An operation control unit for controlling the output of the PWM signal supplied to the output, the operation control unit outputs a PWM signal when the current instruction value is larger than an arbitrary threshold voltage, and the current instruction value is arbitrary When the voltage is smaller than the threshold voltage, the output of the PWM signal is stopped.

  According to the present invention, the output current instruction unit includes an error amplifier that outputs an error amount between the output voltage of the power supply device and the reference voltage as a current instruction value, and the operation control unit includes a current instruction output from the error amplifier. A comparator that determines whether or not the current indication value is greater than the threshold voltage, and compares the current indication value output from the error amplifier and the output current of the power supply device. Based on the comparison result, a hysteresis comparator that generates and outputs a PWM signal to be output to the pre-driver, and a PWM signal that is generated by the hysteresis comparator when the comparator determines that the current instruction value is greater than the threshold voltage are output. Stops the output of the PWM signal generated by the hysteresis comparator when the comparator determines that the current indication value is smaller than the threshold voltage. In which more the that the output judging unit.

  Among the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  (1) A stable output voltage can be output even if the load current amount fluctuates.

  (2) In addition, a highly accurate voltage can be generated at low cost without increasing the circuit scale of the power supply device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

(Embodiment 1)
FIG. 1 is a circuit diagram showing a configuration example of a switching regulator according to Embodiment 1 of the present invention, and FIG. 2 is a timing chart showing operation timings in the switching regulator of FIG.

  In the first embodiment, the switching regulator 1 is mounted on, for example, a mobile hard disk drive (HDD) and converts a DC voltage to an arbitrary DC voltage.

  The switching regulator 1 is an output current feedback type step-up switching regulator. As shown in FIG. 1, the capacitance elements 2 and 3, the diode 4, the resistors 5 to 8, the coil 9, the transistor 10, the error amplifier 11, and the comparator 12, a hysteresis comparator 13, an AND circuit 14, and a pre-driver 15.

  Further, the resistors 7 and 8, the transistor 10 constituting the driver unit, the error amplifier 11, the comparator 12, the hysteresis comparator 13, the AND circuit 14, and the pre-driver 15 constituting the driver constitute a voltage generation control unit. The generation control unit is provided in, for example, a semiconductor integrated circuit device.

  Furthermore, the electrostatic capacitance elements 2 and 3, the diode 4, the resistors 5 and 6, and the coil 9 are configured to be externally connected to a semiconductor integrated circuit device, for example. Here, the transistor 10 may be externally connected without being provided in the semiconductor integrated circuit device.

  A power supply voltage is connected to one connection portion of the resistor 5 and one connection portion of the capacitance element 3. One connection portion of the coil 9 is connected to the other connection portion of the resistor 5.

  One connection portion of the resistor 6 is connected to the other connection portion of the capacitive element 3, and one connection portion of the coil 9, the anode of the diode 4, And one connection part of the transistor 10 is connected, respectively.

  One connection part of the capacitive element 2 is connected to the cathode of the diode 4, and the reference potential VSS is connected to the other connection part of the capacitive element 2. One connection portion of the capacitive element 2 serves as a voltage output portion of the switching regulator 1 and outputs an output voltage Vo to the load L.

  A resistor 7 and a resistor 8 are connected in series between one connection portion of the capacitance element 2 (voltage output portion of the switching regulator 1) and the reference potential VSS. A positive (+) side input terminal of an error amplifier (error amplifier) 11 serving as an output current instruction unit is connected to a connection portion between the resistor 7 and the resistor 8.

  A reference voltage VREF is connected to the negative (−) side input terminal of the error amplifier 11, and the negative (−) side input terminal of the comparator 12 is connected to the output part of the error amplifier 11, and The negative (−) side input terminals of the hysteresis comparator 13 are connected to each other.

  The positive (+) side input terminal of the comparator 12 is connected so that a reference voltage STOPREF serving as a threshold voltage is input, and one input of the AND circuit 14 is connected to the output portion of the comparator 12. Are connected.

  The other input part of the AND circuit 14 is connected to the output part of the hysteresis comparator 13, and the connection between the capacitive element 3 and the resistor 6 is connected to the positive (+) side input terminal of the hysteresis comparator 13. Are connected.

  The gate of the transistor 10 is connected to the output part of the AND circuit 14, and the reference potential VSS is connected to the other connection part of the transistor 10. The operation controller is configured by the comparator 12, the hysteresis comparator 13, and the AND circuit 14.

  Next, the operation of the switching regulator 1 in the present embodiment will be described.

  The switching regulator 1 has a normal operation mode and a light load operation mode. The normal operation mode is an operation mode when the load L is performing a normal operation, and the light load mode is an operation mode when the load L is a light load due to a standby state or the like.

  The detection of the output current is performed by the electrostatic capacitance element 3 and the resistor 6, and electromagnetic energy is stored in the coil 9 connected to the power supply voltage by the switching operation of the transistor 10 to perform the boosting operation.

  When the transistor 10 is turned on, electromagnetic energy is stored in the coil 9, and when the transistor 10 is turned off, the boosted output voltage Vo is obtained by storing electric charge in the capacitive element 2 serving as a smoothing capacitor through the rectifying diode 4. obtain.

  The output voltage Vo is divided by the resistors 7 and 8 and input to the error amplifier 11. The error amplifier 11 inputs an error amount between the divided voltage and the reference voltage VREF to the hysteresis comparator 13.

  Since the value of the output current detected by the capacitive element 3 and the resistor 6 is input to the positive (+) side input terminal of the hysteresis comparator 13, the signal output from the error amplifier 11 is the output voltage. The current instruction value is proportional to the load current value necessary to maintain Vo.

  The hysteresis comparator 13 outputs a Hi level or Lo level signal depending on the magnitude relationship between the current instruction value input from the error amplifier 11 and the output current value detected by the capacitance element 3 and the resistor 6.

  This Hi level or Lo level signal is input to the pre-driver 15 via the AND circuit 14, and the pre-driver 15 drives the transistor 10 ON / OFF to perform the PWM control operation.

  Further, the comparator 12 compares the output (current instruction value) of the error amplifier 11 with an arbitrary reference voltage STOPREF (threshold value voltage), and the current instruction value becomes higher than the reference voltage STOPREF (the current instruction value becomes smaller). A Lo level signal is output.

  Since the signal output from the comparator 12 is input to one input unit of the AND circuit 14, PWM control is performed while the output signal of the comparator 12 is at the Hi level, and the output signal of the comparator 12 is at the Lo level. Then, the transistor 10 is turned off regardless of the output signal of the hysteresis comparator 13.

  Next, the operation of the switching regulator 1 in the light load mode will be described.

  FIG. 2 is a timing chart showing the operation timing in the switching regulator 1. 2, from the top to the bottom, the output voltage Vo of the switching regulator 1, the operation of the transistor 10 (PWM control), the current indication value output from the error amplifier 11, and the load current of the load L connected to the switching regulator 1 The signal timings in FIG.

  First, in the normal operation mode in which the load current flowing through the switching regulator 1 is large (FIG. 2, period t1), the error amplifier 11 outputs a voltage (for example, 0 V) of a current instruction value for flowing a large current. .

  Therefore, since the Hi level signal is output from the comparator 12, continuous PWM control (normal operation mode) is performed by the Hi level / Lo level signal output from the hysteresis comparator 13.

  Subsequently, when the load L transitions from the operating state to the standby state or the like, and the load current flowing through the switching regulator 1 starts to decrease (period t2 in FIG. 2), the load is output from the error amplifier 11 in proportion thereto. The voltage level of the current indication value increases.

  When the current instruction value output from the error amplifier 11 becomes higher than the reference voltage STOPREF, a Lo level signal is output from the comparator 12, the transistor 10 is turned OFF, the PWM control is stopped, and the operation of the switching regulator 1 is performed. The mode will shift to the light load mode.

  Thereafter, the comparator 12 compares the current instruction value output from the error amplifier 11 with the reference voltage STOPREF, performs PWM control when the current instruction value becomes lower than the reference voltage STOPREF, and the current instruction value becomes higher than the reference voltage STOPREF. Then, the switching operation of the transistor 10 is stopped and the PWM control is stopped.

  As described above, when the load current amount is small and the load is light, the ON timing of the transistor 10 is controlled by the current instruction value, and switching control with suppressed ripple of the output voltage Vo can be performed.

  Therefore, when the current instruction value is smaller than the reference voltage STOPREF, the switching regulator 1 automatically operates in the light load mode. When the current instruction value is in the vicinity of the voltage level of the reference voltage STOPREF, the operation in the normal operation mode and the light load mode is mixed, and the mixture ratio is gradually switched as the current instruction value decreases.

  Therefore, it is possible to suppress the voltage fluctuation of the output voltage Vo when switching between the normal operation mode and the light load mode. In addition, since the reference voltage STOPREF serving as a threshold voltage is provided as the current instruction value and only the ON timing of the transistor 10 is controlled, the circuit configuration is simplified and the operation in the normal operation mode / light load mode can be easily performed. Can be realized.

  Thus, according to the first embodiment, a stable output voltage Vo can be output even if the load current amount fluctuates.

  In addition, the switching regulator 1 can be realized with low cost and high accuracy without increasing the circuit scale.

(Embodiment 2)
FIG. 3 is a circuit diagram showing a configuration example of the switching regulator according to the second embodiment of the present invention, and FIG. 4 is a timing chart showing operation timings in the switching regulator of FIG.

  In the second embodiment, the switching regulator 1a is a step-down switching regulator. As shown in FIG. 3, the switching regulator 1 a includes capacitance elements 2 and 3, a diode 4, resistors 5 to 8, a coil 9, a transistor 10, an error amplifier 11, a comparator 12, a hysteresis comparator 13, and a pre-driver 15. In this configuration, an OR circuit 14a is added in place of the AND circuit 14 in the same configuration as in the first embodiment (FIG. 1).

  Here again, the resistors 7 and 8, the transistor 10, the error amplifier 11, the comparator 12, the hysteresis comparator 13, the OR circuit 14a, and the pre-driver 15 constitute a voltage generation control unit. The integrated circuit device is provided.

  The other electrostatic capacitance elements 2 and 3, the diode 4, the resistors 5 and 6, and the coil 9 are configured to be externally connected to a semiconductor integrated circuit device, for example. Further, the transistor 10 may be externally connected without being provided in the semiconductor integrated circuit device.

  One connection portion of the transistor 10 is connected to be supplied with a power supply voltage, and the other connection portion of the transistor 10 is connected to the cathode of the diode 4 and one connection portion of the resistors 5 and 6, respectively. It is connected.

  A reference potential VSS is connected to the anode of the diode 4. One connecting portion of the capacitive element 3 is connected to the other connecting portion of the resistor 6, and the positive (+) of the hysteresis comparator 13 is connected to the connecting portion of the resistor 6 and the capacitive element 3. Side input terminal is connected.

  One connection portion of the coil 9 is connected to the other connection portion of the resistor 5, and the other connection portion of the capacitance element 3 and the capacitance element are connected to the other connection portion of the coil 9. One of the two connecting portions is connected.

  A reference potential VSS is connected to the other connection portion of the capacitance element 2, and one connection portion of the capacitance element 2 serves as a voltage output portion of the switching regulator 1 a and outputs to the load L. The voltage Vo is output.

  One input part of the OR circuit 14 a is connected to the output part of the comparator 12, and the other input part of the OR circuit 14 a is connected to the output part of the hysteresis comparator 13.

  Further, the input part of the pre-driver 15 is connected to the output part of the OR circuit 14a. Since other connection configurations are the same as those in the first embodiment (FIG. 1), description thereof is omitted.

  The switching regulator 1a is a step-down switching regulator controlled by a hysteretic comparator that detects the output current by the resistor 6 and the capacitance element 3, and electromagnetic energy is applied to the coil 9 connected to the power supply voltage by the switching operation of the transistor 10. Is stored to perform step-down operation.

  When the transistor 10 is turned on, electromagnetic energy is stored in the coil 9, and a regenerative current is generated from the reference potential VSS through the rectifying diode 4 when the transistor 10 is turned off. Then, the output voltage Vo is obtained by storing this current in the capacitive element 2 which is a smoothing capacitor.

  The output voltage Vo is divided by the resistors 7 and 8 and input to the error amplifier 11. The error amplifier 11 inputs an error amount with respect to the reference voltage VREF to the hysteresis comparator 13.

  The value detected by the resistor 6 and the capacitive element 3 is input to the positive (+) side input terminal of the hysteresis comparator 13, and the output is the current indication value as in the first embodiment. It becomes.

  The hysteresis comparator 13 outputs a Hi level / Lo level signal according to the magnitude relationship between the current indication value input from the error amplifier 11 and the output current value detected by the resistor 6 and the electrostatic capacitance element 3, and the transistor 10 is turned ON / OFF and becomes a PWM operation.

  The comparator 12 outputs a Hi level signal when the current instruction value becomes lower than a certain reference voltage STOPREF (the current instruction value becomes smaller).

  The output signal of the comparator 12 is logically summed with the output signal of the hysteresis comparator 13 by the OR circuit 14 a and input to the pre-driver 15. When the output signal of the comparator 12 becomes Hi level, the transistor 10 is turned off regardless of the output signal of the hysteresis comparator 13.

  FIG. 4 is a timing chart showing the operation timing in the switching regulator 1a. In FIG. 4, from the upper side to the lower side, the output voltage Vo of the switching regulator 1a, the operation of the transistor 10 (PWM control), the current instruction value output from the error amplifier 11, and the load current of the load L connected to the switching regulator 1a The signal timings in FIG.

  The switching regulator 1a is also configured to have a normal operation mode and a light load operation mode, as in the first embodiment.

  First, in the normal operation mode (FIG. 4, period t1), the error amplifier 11 outputs a voltage of a current instruction value for flowing a large current, and the comparator 12 outputs a Lo level signal. Therefore, a Hi level / Lo level signal is output from the hysteresis comparator 13, and continuous PWM control (normal operation mode) is performed.

  Subsequently, when the load current flowing through the switching regulator 1a starts to decrease (FIG. 4, period t2), the voltage level of the current instruction value output from the error amplifier 11 decreases in proportion thereto.

  When the current instruction value output from the error amplifier 11 becomes lower than the reference voltage STOPREF, a Hi level signal is output from the comparator 12, the transistor 10 is turned OFF, the PWM control is stopped, and the operation of the switching regulator 1a is performed. The mode will shift to the light load mode.

  Thereafter, the comparator 12 compares the current instruction value output from the error amplifier 11 with the reference voltage STOPREF, performs PWM control when the current instruction value becomes higher than the reference voltage STOPREF, and the current instruction value is lower than the reference voltage STOPREF. Then, the switching operation of the transistor 10 is stopped and the PWM control is stopped.

  Thereby, also in the second embodiment, it is possible to perform stable switching control while suppressing the ripple of the output voltage Vo.

  In addition, the switching regulator 1a can be realized with low cost and high accuracy without increasing the circuit scale.

(Embodiment 3)
FIG. 5 is a circuit diagram showing a configuration example of a switching regulator according to the third embodiment of the present invention.

  In the third embodiment, the switching regulator 1b is composed of a peak current control type step-down switching regulator, and as shown in FIG. 5, NAND circuits 16 and 17, a trigger generator 18 and an oscillator 19 constituting a flip-flop. The configuration in which the resistor 20 and the resistor 20 are newly added and the resistor 6 and the capacitance element 3 are deleted is different from the switching regulator 1a (FIG. 3).

  Here again, the resistors 7 and 8, the transistor 10, the error amplifier 11, the comparator 12, the hysteresis comparator 13, the logical sum circuit 14 a, the pre-driver 15, the negative logical product circuits 16 and 17, the trigger generator 18, and the oscillator 19, A generation control unit is configured, and the voltage generation control unit is provided, for example, in a semiconductor integrated circuit device.

  The electrostatic capacitance element 2, the diode 4, the resistors 5 and 20, and the coil 9 are externally connected to the semiconductor integrated circuit device. Further, the transistor 10 may be externally connected without being provided in the semiconductor integrated circuit device.

  In this case, a power supply voltage is connected to one connection portion of the resistor 20, and one connection portion of the transistor 10 is connected to the other connection portion of the resistor 20. Further, the input part of the trigger generator 18 is connected to the output part of the oscillator 19.

  The other input part of the negative AND circuit 17 is connected to the output part of the trigger generator 18, and the pulse output from the trigger generator 18 is input to the other input part of the negative AND circuit 17. The

  One input part of the NAND circuit 16 is connected to the output part of the hysteresis comparator 13, and the output part of the NAND circuit 17 is connected to the other input part of the NAND circuit 16. ing.

  One input part of the negative logical product circuit 17 and one input part of the logical sum circuit 14a are connected to the output part of the negative logical product circuit 16, respectively. Other connection configurations are the same as those in FIG. 3 of the second embodiment. In this case, the frequency of PWM control is set by a pulse generated by the oscillator 19 and the trigger generator 18.

  The operations in the normal operation mode and the light load operation mode in the switching regulator 1b are the same as those in the second embodiment (FIG. 4), and thus the description thereof is omitted.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  The present invention is suitable for an output voltage stabilization technique in a switching regulator.

It is a circuit diagram which shows the structural example of the switching regulator by Embodiment 1 of this invention. 2 is a timing chart showing operation timing in the switching regulator of FIG. 1. It is a circuit diagram which shows the structural example of the switching regulator by Embodiment 2 of this invention. It is a timing chart which shows the operation timing in the switching regulator of FIG. It is a circuit diagram which shows the structural example of the switching regulator by Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Switching regulator 1a Switching regulator 1b Switching regulator 2, 3 Capacitance element 4 Diode 5-8 Resistance 9 Coil 10 Transistor 11 Error amplifier 12 Comparator 13 Hysteresis comparator 14 AND circuit 14a OR circuit 15 Pre-driver 16, 17 Negative logic Product circuit 18 Trigger generator 19 Oscillator 20 Resistance

Claims (5)

A power supply device that converts a DC power supply voltage into an arbitrary DC voltage,
A driver unit that performs switching based on the PWM signal;
An output current instruction unit for generating a current instruction value indicating an output current output from the power supply device;
An operation control unit for controlling the output of the PWM signal supplied to the driver unit based on the current command value output from the output current command unit;
The operation controller is
The PWM signal is output when the current instruction value is larger than an arbitrary threshold voltage, and the output of the PWM signal is stopped when the current instruction value is smaller than an arbitrary threshold voltage. Power supply. The power supply device according to claim 1, wherein
The output current indicator is
An error amplifier that outputs an error amount between the output voltage of the power supply device and a reference voltage as a current indication value,
The operation controller is
A comparator that compares the current indication value output from the error amplifier with the threshold voltage and determines whether the current indication value is greater than the threshold voltage;
Comparing the current instruction value output from the error amplifier with the output current of the power supply device, and according to the comparison result, a hysteresis comparator that generates and outputs a PWM signal for driving the driver unit;
A PWM signal generated by the hysteresis comparator when the comparator determines that the current instruction value is larger than the threshold voltage, and the comparator indicates that the current instruction value is smaller than the threshold voltage. A power supply apparatus comprising: an output determination unit that stops output of the PWM signal generated by the hysteresis comparator when the determination is made. The power supply device according to claim 1 or 2,
The power supply device
An output current feedback type switching regulator. A semiconductor integrated circuit device including a voltage generation control unit used in a power supply device that converts a DC power supply voltage into an arbitrary DC voltage,
The voltage generation control unit
A pre-driver that drives a driver that performs switching based on the PWM signal;
An output current instruction unit for generating a current instruction value indicating an output current output from the power supply device;
An operation control unit for controlling the output of the PWM signal supplied to the pre-driver based on the current command value output from the output current command unit;
The operation controller is
The PWM signal is output when the current instruction value is larger than an arbitrary threshold voltage, and the output of the PWM signal is stopped when the current instruction value is smaller than an arbitrary threshold voltage. A semiconductor integrated circuit device. The semiconductor integrated circuit device according to claim 4.
The output current indicator is
An error amplifier that outputs an error amount between the output voltage of the power supply device and a reference voltage as a current indication value,
The operation controller is
A comparator that compares the current indication value output from the error amplifier with the threshold voltage and determines whether the current indication value is greater than the threshold voltage;
A hysteresis comparator that compares the current instruction value output from the error amplifier with the output current of the power supply device and generates and outputs a PWM signal to be output to the pre-driver according to the comparison result;
A PWM signal generated by the hysteresis comparator when the comparator determines that the current instruction value is larger than the threshold voltage, and the comparator indicates that the current instruction value is smaller than the threshold voltage. A semiconductor integrated circuit device comprising: an output determination unit that stops output of the PWM signal generated by the hysteresis comparator when the determination is made.

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