|Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 General Description
The is a high performance AC/DC power supply controller for battery charger and adapter applications. The device uses Pulse Frequency Modulation (PFM) method to build discontinuous conduction mode (DCM) flyback power supplies. The AP3706 provides constant voltage, constant current (CV/CC) regulation without requiring an optocoupler and secondary control circuitry. It also eliminates the need of loop compensation circuitry while maintaining stability. The AP3706 achieves excellent regulation and high power efficiency, the no-load power consumption is less than at 265VAC input. The AP3706 is available in SOIC-8 and DIP-8 packages.
· Primary Side Control for Rectangular Constant Current and Constant Voltage Output Eliminates Opto-Coupler and Secondary CV/CC Control Circuitry Eliminates Control Loop Compensation Circuitry Flyback Topology in DCM Operation Random Frequency Modulation to Reduce System EMI Valley Turn on of External Power NPN Transistor Built-in Soft Start Open Circuit Protection Over Voltage Protection Short Circuit Protection
· Adapters/Chargers for Cell/Cordless Phones, PDAs, MP3 and Other Portable Apparatus Standby and Auxiliary Power Supplies
Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Pin Configuration
Pin Number Pin Name CS VCC OUT GND FB VDD BIAS COMP The primary current sense Supply voltage This pin drives the base of external power NPN switch Ground The voltage feedback from the auxiliary winding The 5V output of the internal voltage regulator This pin sets the bias current inside AP3706 with an external resistor to GND This pin connects a bypass capacitor for CC function Function
Data Sheet PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS AP3706 Functional Block Diagram