A REDUCTION OF STANDBY POWER OF SMPS THROUGH POWER CONTROL OF PWM IC

摘要

An apparatus for reducing standby power of an SMPS(Switching Mode Power Supply) using a PWM IC is provided to improve power reduction efficiency by changing the SMPS into a sleep mode, when a standby mode is sustained for more than a predetermined time. A low power mode determining unit(1) compares a feedback signal from a load stage with signals due to a variation in a load, and supplies a compared result to a sleep mode determining unit. A clock generator(3) generates a reference clock. A low power counter(4) counts the reference clocks and applies a clock signal to the sleep mode determining unit. The sleep mode determining unit(2) generates a switch block control signal based on the signals from the low power mode determining unit and the counter and an external interrupt signal. The switch block(7) is driven by the control signal from the sleep mode determining unit. A power controller(6) controls a PWM(Pulse Width Modulation) controller(5).