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Preliminary Datasheet
CURRENT MODE PWM CONTROLLER FOR BJT
AP3720
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 20kHz (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 compensation, line compensation, and several protection features.