Mode control circuit for switching regulators and method therefor

摘要

A mode control method and apparatus for a switching regulator is disclosed. The method receives an input signal and amplifying the input signal to get an amplified signal. The amplified signal is sent to a sample circuit to get a sample signal. The sample signal is delivered to an averaging circuit to get an averaged sensed output signal. The averaged sensed output signal is compared with a first pre-determined threshold or an second pre-determined threshold to get a PWM enable signal. The appropriate mode is determined based on the PWM enable signal.