SG6859A

SG6859A — Low Cost, Green-Mode PWM Controller for Flyback Converters SG6859A Low-Cost, Green-Mode PWM Controller for Flyback Converters Features  Green-Mode PWM  Supports the “Blue Angel” Standard  Low Startup Current: 9 μA  Low Operating Current: 3 mA  300 mA Driving Capability  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 (Auto Restart)  Gate Output Voltage Clamped at 17 V  Low Cost  Few External Components Required  Small SOT23-6L 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, the 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 the strictest power conservation requirements. The BiCMOS fabrication process enables reducing the startup current to 9 μA and the operating current to 3 mA. To further improve power conservation, a large startup 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 univer...