3843CM Datasheet | BCD Semiconductor

Description The AP3842C/3C/4C/5C are high performance fixed frequency current-mode PWM controller series. These integrated circuits are optimized for off-line and DC-DC converter applications with minimum external ponents. They feature under-voltage lockout .. (UVLO) circuit with low start-up current, trimmed oscillator for precise duty cycle control, current sense parator providing maximum current limiting and a totem pole output stage for increasing output current. In addition, these ICs also feature accurate protection against over-temperature, over-current and maximal output power. The AP3842C and AP3844C have UVLO thresholds of 16V(on) and 10V(off); The corresponding thresholds for AP3843C and AP3845C are 8.4 V(on) and 7.6V(off). The AP3842C and AP3843C can operate approaching 100% duty cycle; AP3844C and AP3845C can operate from zero to 50% duty cycle. These ICs are available in SOIC-8 and DIP-8 packages. AP384XC Features - - - - - - - - Low Start-up Current: 50µA Robust VREF Line/Load Regulation Low Line Regulation : 4m V Low Load Regulation : 4m V High Stability of Reference Voltage over a Full Temperature Range: 0.2m V/ o C Operating Frequency up to 500KHz High PWM Frequency Stability over a Full Temperature Range: 2.5% High PWM Frequency Stability under a Full Supply Voltage Range: 0.2% Accurate Over-temperature Protection with Hysteresis UVLO with Hysteresis Applications - - - - - - Off-line Converter DC-DC Converter Voltage Adapter CRT Monitor Power Supply Desktop Power Supply DVD/STB Power Supply SOIC-8 DIP-8 Figure 1. Package Types of AP3842C/3C/4C/5C Sep. 2006 Rev. 1. 1 BCD Semiconductor Manufacturing Limited Data Sheet CURRENT MODE PWM CONTROLLER Pin Configuration AP384XC P/M Package (DIP-8/SOIC-8) P VFB ISENSE RT/CT 1 2 3 4 8 7 6 5 VREF VCC OUTPUT GND .. Figure 2. Pin Configuration of AP3842C/3C/4C/5C (Top View) Pin Description Pin Number 1 2 3 4 Pin Name P VFB ISENSE RT/CT Function This pin is the Error Amplifier output and is made...