Product Summary

The C5546 is a Single-Stage Power Factor Corrected Off-Line Switching Regulators. It is designed for input capacitor less applications, and making it possible for systems to comply with the harmonics standard (IEC61000-3-2 class C). The C5546 incorporates separate controller and power MOSFET chips. The controller adapts the average current control method for realizing high power factors, and the quasi-resonant topology contributes to high efficiency and low EMI noise. The rich set of protection features helps to realize low component counts, and high performance-to-cost power supply. The applications of the C5546 include LED lighting fixtures, LED light bulbs.

Parametrics

C5546 absolute maximum ratings: (1)Drain Current: 4.0A; (2)Single Pulse Avalanche Energy (ILPeak=2.7A, VDD=99V, L=10mH): 86mJ; (3)Input Voltage for Control Part (MIC): 35V; (4)OCP Pin Voltage: -1.0V to 5.0V; (5)FB Pin Voltage: -0.3V to 7.0V; (6)OVP Pin Voltage: -0.5V to 5.0V; (7)Allowable Power Dissipation: 0.97W; (8)Operating Ambient Temperature: -55℃ to 125℃; (9)Storage Temperature: -55℃ to 125℃; (10)Channel Temperature: 150℃.

Features

C5546 features: (1)Integrated on-width control circuit (it realizes high power factor by average current control); (2)Integrated startup circuit (no external startup circuit necessary); (3)Integrated soft-start circuit (reduces power stress during start-up on the incorporated power MOSFET and rectifier); (4)Integrated bias assist circuit (improves the startup performance, suppresses VCC voltage droop during operation, allows reduction of VCC capacitor value as well as use of a ceramic capacitor); (5)Integrated Leading Edge Blanking (LEB) circuit; (6)Integrated maximum on-time limit circuit; (7)Dual-chip structure, with an avalanche-guaranteed power MOSFET (allows simplified surge suppressing circuits); (8)Over current protection (OCP): pulse-by-pulse; (9)Over voltage protection (OVP): latched shutdown; (10)Overload protection (OLP): latched shutdown; (11)Thermal shutdown (TSD): latched shutdown.

Diagrams

C5546 block diagram