MC34261

www.DataSheet4U.com MC34261, MC33261 Power Factor Controllers The MC34261/MC33261 are active power factor controllers specifically designed for use as a preconverter in electronic ballast and in off−line power converter applications. These integrated circuits feature an internal startup timer, a one quadrant multiplier for near unity power factor, zero current detector to ensure critical conduction operation, high gain error amplifier, trimmed internal bandgap reference, current sensing comparator, and a totem pole output ideally suited for driving a power MOSFET. Also included are protective features consisting of input undervoltage lockout with hysteresis, cycle−by−cycle current limiting, and a latch for single pulse metering. These devices are available in dual−in−line and surface mount plastic packages. Internal Startup Timer One Quadrant Multiplier Zero Current Detector Trimmed 2% Internal Bandgap Reference Totem Pole Output Undervoltage Lockout with Hysteresis Low Startup and Operating Current Pinout Equivalent to the SG3561 Functional Equivalent to the TDA4817 http://onsemi.com POWER FACTOR CONTROLLERS SEMICONDUCTOR TECHNICAL DATA 8 1 P SUFFIX PLASTIC PACKAGE CASE 626 8 1 Simplified Block Diagram D SUFFIX PLASTIC PACKAGE CASE 751 (SO−8) Zero Current Detector 5 Zero Current Detect Input PIN CONNECTIONS 2.5V Reference Undervoltage Lockout VCC 8 Voltage Feedback Input Compensation Multiplier Input Current Sense Input 1 2 3 4 (Top View) 8...