PWM SIGNAL CONTROL DEVICE FOR SMPS MANAGEMENT IC BY USING EXTERNAL SIGNALS

摘要

An SMPS controller is provided to change a reference voltage for determining a standby state of the SMPS device by using a digital signal in the outside of the SMPS controller. An SMPS(Switching Mode Power Supply) controller includes a DAC(Digital to Analog Converter)(7), a standby mode determining unit(2), and a PWM(Pulse Width Modulation) signal controller(3). The DAC converts an external digital signal to an analog signal and generates an analog reference voltage for determining a standby mode state. The standby mode determining unit compares the standby mode determining voltage defined by the converted analog signal with the voltage which is fed back from an output portion of an SMPS to determine a standby mode. The PWM signal controller receives the outputs from the standby mode determining unit and a PWM modulator, and provides the received signals to an output driver which outputs a driving signal for a power semiconductor device. A reference voltage value for determining the standby mode state is programmed by using an external signal.