FairchildFAN6920MR临界模式PFC电源解决方案

Fairchild公司的FAN6920MR是采用mWSaver技术的集成了临界模式PFC控制器和准谐振电流模式PWM控制器,提供了成本效益的设计和降低了外接元件. FAN6920MR具有谷低检测,绿色模式工作以及高/低火线电压超功率补偿,从而提高了电源系统的性能,主要用在笔记本电脑适配器,开架开关电源和电池充电器.本文介绍了FAN6920MR主要特性,方框图, 典型应用电路图, 设计案例最终电路图,材料清单和PCB布局考虑.

FAN6920MR: mWSaver™ Technology Integrated Critical-Mode PFC and Quasi-Resonant Current-Mode PWM Controller

Factor Correction (PFC) controller and quasi-resonant PWM controller. Integration provides cost-effective design and reduces external components.

For PFC, FAN6920MR uses a controlled on-time technique to provide a regulated DC output voltage and to perform natural power-factor correction. With an innovative THD optimizer, FAN6920MR can reduce input current distortion at zero-crossing duration to
improve THD performance.

For PWM, FAN6920MR provides several functions to enhance the power system performance: valley detection, green-mode operation, and high / low line over-power compensation. Protection functions include secondary-side open-loop and over-current with autorecovery protection; external auto-recovery triggering; adjustable over-temperature protection by RT pin; and external NTC resistor, internal over-temperature shutdown, VDD pin OVP, and DET pin over-voltage for output OVP, and brown-in / out for AC input voltage UVP.

The FAN6920MR controller is available in a 16-pin small-outline package (SOP).

FAN6920MR主要特性:

 Integrated PFC and Flyback Controller

 Critical-Mode PFC Controller

 Zero-Current Detection for PFC Stage

 Quasi-Resonant Operation for PWM Stage

 Internal Minimum 5μs tOFF for QR PWM Stage

 Internal 5ms Soft-Start for PWM

 Brownout Protection

 High / Low Line Over-Power Compensation

 Auto-Recovery Over-Current Protection

 Auto-Recovery Open-Loop Protection

 Externally Auto-Recovery Triggering (RT Pin)

 Adjustable Over-Temperature Protection

 VDD Pin and Output Voltage OVP (Auto-Recovery)

 Internal Over-Temperature Shutdown (140°C)

FAN6920MR应用:

 AC/DC NB Adapters

 Open-Frame SMPS

 Battery Charger

图1.FAN6920MR方框图

图2.FAN6920MR典型应用电路图

图3.FAN6920MR设计案例最终电路图

图4. 设计案例布局考虑
设计案例材料清单: