PWM driving circuit and PWM driving method

摘要

Provided is a PWM driving circuit and a PWM driving method. The PWM driving circuit includes a dimmer switching unit turning on a first switch to apply a first reference signal varied according to an input voltage of a system when an output voltage level of a dimmer is a reference level or less, and turning on a second switch to apply a second reference signal, unrelated to the input voltage of the system, when the output voltage level of the dimmer is more than the reference level, an error amplification unit comparing the first reference signal or the second reference signal with an output detection signal to amplify an error and outputting an error amplification signal, and a PWM control signal generating unit comparing the error amplification signal of the error amplification unit with a predetermined reference waveform to output a PWM control signal.

主权项

1. A PWM driving circuit, comprising:
a dimmer switching unit configured to turn on a first switch to apply a first reference signal varied according to an input voltage of a system when an output voltage level of a dimmer is a reference level or less than the reference level, and turn on a second switch to apply a second reference signal, unrelated to the input voltage of the system, when the output voltage level of the dimmer is more than the reference level or the reference level; an error amplification unit configured to compare the first reference signal or the second reference signal applied from the dimmer switching unit with an output detection signal fed back by detecting an output of the system to amplify an error and output an error amplification signal; and a PWM control signal generating unit configured to compare the error amplification signal of the error amplification unit with a predetermined reference waveform to output a PWM control signal.