The FSL4110LR is an integrated pulse width modulation (PWM) controller and 1000 V avalanche rugged SenseFET specifically designed for high input voltage offline Switching Mode Power Supplies (SMPS) with minimal external components. VCC can be supplied through integrated high-voltage power regulator without auxiliary bias winding.
The FSL4110LR eliminates the need for external components found in alterantive solutions; it integrates a VDMOS SenseFET (BVDSS = 1000V) with built-in line compensation for wide input voltage range from 45 to 460 Vac. It also includes built-in input over- voltage protection and a safe auto-restart mode for all protection conditions.
Fairchild says that its power switch is the only solution of its kind that provides Abnormal Over Current Protection (AOCP), which protects the power converter from transformer abnormalities and is particularly important for smart metering applications: the FSL4110LR is a solution for any designer implementing flyback converters that need to meet three phase input voltage or unstable single phase input voltage requirements.
The integrated PWM controller includes a fixed-frequency oscillator, Under-Voltage Lockout (UVLO), Leading-Edge Blanking (LEB), optimised gate driver, soft-start, temperature-compensated precise current sources for loop-compensation, and variable protection circuitry.
It operates with a precise fixed operating frequency of 50 kHz; VCC can be supplied from either bias-winding or self-biasing; soft burst-mode operation minimises audible noise; random frequency fluctuations reduce EMI; there is pulse-by-pulse current limit in addition to the other protection functions. A fixed 1.6 sec restart time gives safe auto-restart mode of all protections.