| 摘要 |
A switching regulator control circuit for PFM control of a DC-DC converter includes a reference voltage producing circuit, a voltage dividing circuit for dividing an output voltage of the DC-DC converter, a comparator for comparing the reference voltage and the divided voltage and outputting a comparison signal, a ring oscillator for outputting a signal for controlling the output transistor, which controls the output voltage of the DC-DC converter, and a logic OR circuit having a first input connected to an output of the ring oscillator and a second input connected to the comparison signal and an output connected to an input of the ring oscillator. Even when the output of the comparator varies frequently, such as when an output voltage closely approaches a set voltage, the ON period of the output transistor remains stable.
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