| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital control switching power supply device having excellent transient response characteristics by using an A/D conversion circuit capable of optimizing conversion time according to a switching frequency. SOLUTION: The switching power supply device converts an input voltage Vin to a desired output Vout by a PWM signal to be subjected to digital control. the A/D conversion circuit includes a delay line circuit 1 which has a delay element array whose delay time is controlled by a delay output current and which converts a current value into a digital signal by the delay time of signal propagation, a phase difference detection circuit 2 for detecting a phase difference between a switching cycle Ts and an A/D conversion cycle, a bias current generation circuit 3 for generating a bias current suited to the phase difference, and a delay control current generation circuit 4 for generating a comparison result of a detection value of an output voltage Vout and a reference voltage Vref and a delay output current signal VIb (out) and a delay reference current signal VIb (ref) from the bias current, and is configured to synchronize an A/D conversion cycle with a switching cycle Ts. COPYRIGHT: (C)2011,JPO&INPIT |
