SG6859A Low Cost, Green-Mode PWM Controller for Flyback Converters January 2015 SG6859A Low-Cost, Green-Mode PWM Controller for Flyback Converters Features Description This highly integrated PWM controller provides several Green-Mode PWM enhancements designed to meet the low standby-power Supports the Blue Angel Standard needs of low-power SMPS. To minimize standby power consumption, the proprietary green-mode function Low Startup Current: 9 A provides off-time modulation to linearly decrease the Low Operating Current: 3 mA switching frequency under light-load conditions. This 300 mA Driving Capability green-mode function enables the power supply to meet even the strictest power conservation requirements. Leading-Edge Blanking The BiCMOS fabrication process enables reducing the Constant Output Power Limit startup current to 9 A and the operating current to Universal Input 3 mA. To further improve power conservation, a large startup resistance can be used. Built-in synchronized Built-in Synchronized Slope Compensation slope compensation ensures the stability of peak Current-Mode Operation current mode control. Proprietary internal compensation Cycle-by-cycle Current Limiting provides a constant output power limit over a universal AC input range (90 V to 264 V ). Pulse-by-pulse AC AC Under-Voltage Lockout (UVLO) current limiting ensures safe operation during short- Programmable PWM Frequency with Frequency circuits. Hopping To protect the external power MOSFET from damage by V Over-Voltage Protection (Auto Restart) DD supply over voltage, the SG6859As output driver is clamped at 17 V. SG6859A controllers can be used to Gate Output Voltage Clamped at 17 V improve the performance and reduce the production Low Cost cost of power supplies. The best choice for replacing linear and RCC-mode power adapters, the SG6859A is Few External Components Required available in 8-pin DIP and 6-pin SOT23-6L packages. Small SOT23-6L Package Applications General-purpose switching mode power supplies and flyback power converters, such as: Battery chargers for cellular phones, cordless phones, PDAs, digital cameras, and power tools Power adapters for ink jet printers, video game consoles, and portable audio players Open-frame SMPS for TV/DVD standby and auxiliary supplies, home appliances, and consumer electronics Replacements for linear transformers and RCC SMPS PC 5 V standby power 2014 Fairchild Semiconductor Corporation www.fairchildsemi.com SG6859A Rev. 1.9 SG6859A Low-Cost, Green-Mode PWM Controller for Flyback Converters Ordering Information Part Number Operating Temperature Range Package Packing Method SG6859ATZ SOT23-6L Tape & Reel SG6859ATY SOT23-6L -40 to +105 C SG6859ADZ DIP-8 Tube SG6859ADY Application Diagram Figure 1. Typical Application Internal Block Diagram DIP(SOT23-6L) Figure 2. Functional Block Diagram 2014 Fairchild Semiconductor Corporation www.fairchildsemi.com SG6859A Rev. 1.9 2