Patent ID: 8253407

Claim:
A voltage mode switching regulator switchable between a pulse width modulation (PWM) mode and a pulse skipping mode, comprising: a power switch circuit including at least one power transistor switch, which converts an input voltage to an output voltage by operating the power transistor switch; an error amplifier generating an error amplification signal by comparing a feedback signal relating to the output voltage with a reference signal; a PWM comparator generating a duty signal according to the error amplification signal and a ramp signal, to thereby control the power transistor switch of the power switch circuit; an error amplification signal clamping circuit, which sets a threshold level of the error amplification signal and a threshold level of the pulse skipping mode, and clamps the error amplification signal so that the error amplification signal is not lower than the threshold level in a power transistor switch on-time control mode, or that the error amplification signal is not higher than the threshold level in a power transistor switch off-time control mode; and a pulse skipping circuit generating a pulse skipping signal when the error amplification signal is less than or equal to the threshold level of the pulse skipping mode, such that the switching regulator enters the pulse skipping mode.