Abstract

This application note describes a typical charger using the PSR controller. Both the features of this controller, as well as the operation of the power supply adaptor, are presented in detail. Based on the proposed design guideline, a design example with detailed parameters is given to demonstrate the superior performance of the controller.

Features

■ Constant-Voltage (CV) and Constant-Current (CC) Control without Secondary-Feedback Circuitry

■ Accurate Constant Current Achieved by Fairchild’s Proprietary TRUECURRENT™ Technique

■ Green-Mode Function: PWM Frequency Decreasing Linearly

■ Fixed PWM Frequency at 42kHz with Frequency Hopping to Solve EMI Problems

■ Low Startup Current: 10μA (Typical)

■ Low Operating Current: 3.5mA (Typical)

■ Peak-Current-Mode Control

■ Cycle-by-Cycle Current Limiting

■ VDD Over-Voltage Protection (OVP)

■ VDD Under-Voltage lockout (UVLO)

■ Gate Output Maximum Voltage Clamped at 18V

■ Fixed Over-Temperature Protection (OTP)

■ Cable Compensation for Tight CV Regulation (FAN102 / FSEZ1216)

Applications

■ Battery chargers for cellular phones, cordless phones, PDAs, digital cameras, power tools

■ Optimal choice for the replacement of linear transformers and RCC SMPS