AMC3845B Datasheet | ADDtek

DESCRIPTION The AMC3842B/43B/44B/45B are fixed frequency current-mode PWM controllers specially designed for OFF-Line switching power supply and DC-to-DC converters with a minimum number of external ponents. These .. devices feature a trimmed oscillator for precise duty cycle control, a temperature pensated reference, high gain error amplifier, current sensing parator, and high current totem pole output which is suitable for driving MOSFETs. The under voltage lock-out (U.V.L.O.) is designed to operated with 200µA start-up current in typical, allowing an efficient bootstrap supply voltage design. The U.V.L.O. thresholds for the AMC3842B/44B are 16V (on) and 10V (off), which are ideal for off-line applications. The corresponding typical threshold for the AMC3843/45BB is 8.4V (on) and 7.6V (off). The AMC3842B/43B can operate within 100% duty cycle and the AMC3844B/45B can operate within 50% duty cycle. APPLICATIONS - - - - - - - - - - - - - CURRENT MODE PWM CONTROLLER FEATURES Low Start-Up current (max. 200µA) Optimized for Off-Line and DC-to-DC Converters Maximum Duty Cycle U.V.L.O. with Hysteresis Operating Frequency Up to 500KHz Internal Trimmed Bandgap Reference High Current Totem Pole Output Error Amplifier With Low Output Resistance Available in 8-Pin Plastic DIP and Surface Mount 14-Pin S.O.I.C. Identical pin assignment to earlier UC384X series. PACKAGE PIN OUT P VREF VCC OUTPUT GND Off-line flyback or forward converters. DC-to-DC buck or boost converter. Monitor Power Supply VFB ISENSE RT/CT 8-Pin Plastic DIP (Top View) AVAILABLE OPTIONS Device AMC3842B AMC3843B AMC3844B AMC3845B Start-UP Voltage 16V 8.4V 16V 8.4V Hysteresis 6V 0.8V 6V 0.8V Max. Duty Cycle < 100% < 100% < 50% < 50% P NC VFB NC ISENSE NC RT/CT VREF NC VCC VC OUTPUT GND PWR RT/CT P VFB ISENSE VREF VCC OUTPUT GND 14-Pin Plastic S.O.I.C. Surface Mount (Top View) 8-Pin Plastic S.O.I.C. Surface Mount (Top View) TA (OC) 0 to 70 0 to 70 Note: ORDER INFORMATION Plastic DIP-8 Plastic SO-14 M...