SG6860

SG6860 — Low-Cost, Green-Mode PWM Controller for Flyback Converters www.DataSheet4U.com March 2008 SG6860 Low-Cost, Green-Mode PWM Controller for Flyback Converters Features ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ Green-Mode PWM Supports the “Blue Angel” Eco Standard Low Start-up Current: 9µA Low Operating Current: 3mA Leading-Edge Blanking Constant Output Power Limit Universal Input Built-in Synchronized Slope Compensation Current Mode Operation Cycle-by-cycle Current Limiting Under-Voltage Lockout (UVLO) Programmable PWM Frequency with Frequency Hopping VDD Over-Voltage Protection (Latch off) Gate Output Voltage Clamped at 17V Low Cost Few External Components Required Small SOT-26 Package Description This highly integrated PWM controller provides several enhancements designed to meet the low standby-power needs of low-power SMPS. To minimize standby power consumption, a proprietary green-mode function provides off-time modulation to linearly decrease the switching frequency under light-load conditions. This green-mode function enables the power supply to meet even strict power conservation requirements. The BiCMOS fabrication process enables reducing the start-up current to 9µA and the operating current to 3mA. To further improve power conservation, a large start-up resistance can be used. Built-in synchronized slope compensation ensures the stability of peak current mode control. Proprietary internal compensation provides a constant output power limit over a universal AC inp...