AN-8024 — Applying Fairchild Power Switch (FPSTM) FSBH-series to Standby Auxiliary Power Supply

The integrated PWM controller features include a proprietary green-mode function that provides off-time modulation to linearly decrease the switching frequency at light-load conditions to minimize standby power consumption. The PWM controller is manufactured using the BiCMOS process to further reduce power consumption. The green and burst modes function with a low operating current (2.5mA in green mode) to maximize the light load efficiency so that the power supply can meet stringent standby power regulations. The FSBH-series has built-in synchronized slope compensation to achieve stable peak-current-mode control. The proprietary external line compensation ensures constant output power limit over a wide AC input voltage range, from 90VAC to 264VAC and helps optimize the power stage.