The AP4340 is an output voltage detector for Primary Side Control System. It detects the output voltage and provides a periodical signal when the output voltage is lower than a certain threshold. The periodical signal can be coupled by the transformer to the primary side and provided as an awakening signal for the main primary side controller. By fast response to secondary side voltage, the AP4340 can effectively improve the transient performance of Primary Side Control System. 

The AP4340 is available in TO-92 and SOT-23 packages.    Applications 

· Adapters/Chargers for Cell/Cordless Phones, 

ADSL Modems, MP3 and Other Portable 

Apparatus 

· Standby and Auxiliary Power Supplies