AP3720 Datasheet | BCD Semiconductor

Preliminary Datasheet CURRENT MODE PWM CONTROLLER FOR BJT General Description The AP3720 is a low startup current, current mode PWM controller with green-mode operation. The PWM switching frequency at normal operation is 65k, but when the output power drops below the specifically level, the device enters the frequency-drop mode and the typical operating frequency is 20k Hz (no audible noise). Additionally, when the load drops to a very low level or zero, the IC operates in so called ‘burst mode’ to minimize switching loss. The IC integrated a lot of functions such as the Lead-Edge Blanking (LEB) of the current sensing, internal slope pensation, line pensation, and several protection Features . The protection functions include cycle-by-cycle current limit (OCP), VCC over voltage protection (OVP), OTP and OLP. The AP3720 is available in DIP-8 and SOIC-8 packages. Features - Low Startup Current (2.5µA) and Low Operating Current (1.2m A) - Off-line Converter Applied in Sub 25W Range - Skip Cycle Mode Achieves Low Standby Power (<200m W) - Cycle-by-Cycle Power Limited - Frequency-drop Mode - Soft Start with 2ms - Programmable Drive Current for BJT - Leading Edge Blanking - Pre-shutdown Decreases Turn-off Losses - Reliable Protection: Accurate OCP with Line pensation Short Circuit Protection Over Voltage Protection for VCC Hysteretic Thermal Shutdown Protection Applications - STB - Cable Modem - ADSL Modem - DVD Recorder Jan. 2013 Rev. 1. 1 DIP-8 SOIC-8 Figure 1. Package Types of AP3720 BCD Semiconductor Manufacturing Limited...