Fairchild公司的FSEZ1317NY是第三代初级边调整（PSR）和高度集成PWM控制器，待机功耗低于300mW,高压起动，具有最少的外接元件，没有次级反馈电路的恒压（CV）和恒流（CC）控制，PWM固定频率50kHz,主要用在手机，无绳电话，PDA,数码相机等充电器，替代线性变压器和RCC开关电源（SMPS）。本文介绍了FSEZ1317主要特性， 功能方框图， 简化PSR反激转换器电路图， 高压起动电路图和6W LED照明驱动器主要特性，电路图和变压器电路图。

    FSEZ1317: Primary-Side-Regulation PWM with POWER MOSFET Integrated

    This third-generation Primary-Side-Regulation （PSR） and highly integrated PWM controller provides several features to enhance the performance of low-power flyback converters. The proprietary topology, TRUECURRENT（TM）， of FSEZ1317 enables precise CC regulation and simplified circuit design for batterycharger applications. A low-cost, smaller, and lighter charger results, as compared to a conventional design or a linear transformer.

    To minimize standby power consumption, the proprietary green mode provides off-time modulation to linearly decrease PWM frequency under light-load conditions. Green mode assists the power supply in meeting power conservation requirements.

    By using the FSEZ1317, a charger can be implemented with few external components and minimized cost.

    FSEZ1317主要特性：

    Low Standby Power Under 30mW

    High-Voltage Startup

    Fewest External Component Counts

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

    Green-Mode: Linearly Decreasing PWM Frequency

    Fixed PWM Frequency at 50kHz with Frequency Hopping to Solve EMI Problem

    Cable Compensation in CV Mode

    Peak-Current-Mode Control in CV Mode

    Cycle-by-Cycle Current Limiting

    VDD Over-Voltage Protection with Auto Restart

    VDD Under-Voltage Lockout （UVLO）

    Gate Output Maximum Voltage Clamped at 15V

    Fixed Over-Temperature Protection with Auto Restart

    Available in the 7-Lead SOP and DIP Packages

    FSEZ1317应用：

    Battery chargers for cELlular phones, cordless phones, PDA, digital cameras, power tools, etc.

    Replaces linear transformers and RCC SMPS

    图1. FSEZ1317功能方框图