| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a circuit and method for controlling a DC/DC converter wherein the average value of output voltage can be quickly determined. Ž<P>SOLUTION: In the control circuit 1, a multiplier 11 multiplies OSC, or a reference signal for PWM signal generation; a counter 21 counts the "H" period or "L" period of a PWM signal with the output of the multiplier 11 used as clock; a register 22 stores the value equivalent to 1/2 of the count value on the counter 21; a sampling pulse generation unit 23 generates a sampling pulse SP1 when the count value on the counter 21 is matched with the value in the register 22; and a sample hold circuit 31 samples divided voltage Vdet of the output voltage Vout of a DC/DC converter 100 by resistors Rdet1, Rdet2 with the sampling pulse SP1 and holds it. The output voltage VFB of the sample hold circuit 31 is supplied to an error detector 110 of the DC/DC converter 100. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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