Patent ID: 9658631
Date: 2017-05-23
CPC Classifications: G01R,G05F,H02M,H03M

Claim:
1. A power supply device comprising: a semiconductor integrated circuit device having a target voltage generating circuit configured to generate a target voltage, a differential amplifier configured to output an error voltage based on the difference between an output voltage and the target voltage, an analog-to-digital (AD) converter configured to convert the error voltage to a digital value and output the digital value as an error signal, and a digital controller configured to output a control signal based on the error signal; a driver configured to output a drive signal based on the control signal; a switching element which is switching controlled by the drive signal; and a smoothing circuit configured to smooth voltage supplied from the switching element and output the smoothed voltage as the output voltage, wherein the AD converter converts a first error voltage as the error voltage to a digital voltage to generate a first error signal as the error signal at a first timing and converts a second error voltage as the error voltage to a digital value to generate a second error signal as the error signal at a second timing before the first timing, and wherein the timing controller generates a prediction value of the error signal at a third timing which is later than the first timing in accordance with the first and second error signals and generates the control signal so that the prediction value lies between a first control threshold and a second control threshold smaller than the first control threshold.