PRIMARY SIDE CONTROL IC FOR OFF-LINE BATTERY CHARGERS SQ6706

General Description

The SQ6706 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 SQ6706 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 SQ6706 achieves excellent regulation and high power efficiency, the no-load power consumption is less than 200mW at 265VAC input. The SQ6706 is available in SOIC-8 package.

Features 

· 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 

Applications 

· Adapters/Chargers for Cell/Cordless Phones, PDAs, MP3 and Other Portable Apparatus 

· Standby and Auxiliary Power Supplies

Figure 1. Package Type of SQ6706

Pin Configuration

igure 2. Pin Configuration of SQ6706 (Top View)

Figure 3. Functional Block Diagram of SQ6706