Patent ID: 9654006
Date: 2017-05-16
CPC Classifications: H02M

Claim:
1. A semiconductor device comprising: a power supply unit that includes an inductor and a switching unit turning on and off under control by a pulse signal to control a current flowing through the inductor, and generates an output voltage by changing an input voltage by an amount of voltage corresponding to a duty ratio of the pulse signal; a first control unit that performs PI control of a first differential signal being a difference between a comparison voltage corresponding to the output voltage and a target voltage and outputs a first control signal; a second control unit that performs PI control of a second differential signal being a difference between the first control signal and a current signal indicating an average value of the current flowing through the inductor and outputs a second control signal; and a PWM generation unit that generates the pulse signal with a duty ratio corresponding to the second control signal, wherein in step-down mode, the second control unit performs proportional control of the second differential signal by using a multiplication result of multiplying the second control signal by a reference proportionality constant as a proportionality constant.