Power-supply device, ic circuit, and information processing apparatus, and soft-start control method
OwnerTakashi Sase, Yosuke Kawakubo +1inventors
InventorsTakashi Sase, Yosuke Kawakubo, Kozaburo Kurita
Life of this patent
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Abstract
An electric current flowing to an upper side power MOSFET during soft-start is detected according to an on-voltage of the MOSFET and an on-pulse width of a PWM pulse for driving the upper side power MOSFET is forced to be reset in the idle and decided according to a signal generated when the voltage falls below a predetermined specified voltage.
Claims20
A power-supply device comprising:
- a pair of power semiconductor switching components;
- driving means for driving the pair of power semiconductor switching components;
- a pulse-width modulation type oscillator that supplies a driving signal to the driving means;
- an error amplifier that supplies an error signal indicating an error between a converted voltage and a reference voltage to the pulse-width modulation type oscillator;
- current detection means for detecting an electric current IH flowing to an upper side power semiconductor switching component of the pair of power semiconductor switching components during soft-start;
- reset means for forcing to reset an on-pulse width, which is outputted from the pulse-width modulation type oscillator, in the middle with a signal generated when the electric current IH increases to be larger than a predetermined specified current;
- and
- on-pulse width decision means for deciding, in response to a reset operation of the reset means, an on-pulse width for driving the upper side power semiconductor switching component during final soft-start.
An information processing apparatus comprising:
- a power-supply device;
- a CPU and a memory that receive supply of a DC voltage from the power-supply device;
- and
- a hard disk device that stores information of the memory, wherein
- the power-supply device includes:
- an error amplifier that functions as a step-down DC-DC converter, which is inputted with a DC input voltage from an input terminal and outputs a stepped-down DC output voltage from an output terminal, and outputs a difference between a reference voltage and the DC output voltage as an error signal;
- a pulse-width modulation type oscillator that subjects the output of the error amplifier to pulse width modulation;
- a driving circuit that generates a driving signal from a pulse signal received from the pulse-width modulation type oscillator;
- a pair of power semiconductor switching components that step down the DC input voltage on the basis of the driving signal from the driving circuit and generates the DC output voltage;
- and
- a soft-start circuit that detects an electric current of the power semiconductor switching components and uses the electric current for a soft-start operation.
An IC circuit formed by integrating a power supply device including an error amplifier that functions as a step-down DC-DC converter, which is inputted with a DC input voltage from an input terminal and outputs a stepped-down DC output voltage from an output terminal, and outputs a difference between a reference voltage and the DC output voltage as an error signal, a pulse-width modulation type oscillator that subjects the output of the error amplifier to pulse width modulation, a driving circuit that generates a driving signal from a pulse signal received from the pulse-width modulation type oscillator, a pair of power semiconductor switching components that step down the DC input voltage on the basis of the driving signal from the driving circuit and generates the DC output voltage, and a soft-start circuit that detects an electric current of the power semiconductor switching components and uses the electric current for a soft-start operation and building the power-supply device in a package of a semiconductor chip including a CPU and a memory.
Dependencies are inferred from the claim text.