TI UCC28810中小功率LED照明应用方案

TI 公司的UCC28810和UCC28811是中小功率通用LED照明电源控制器,具有功率因素修正(PFC)和EMC兼容特性.设计用于工作在临界导通模式的反激,降压或升压转换器. UCC28810/1集成了用于反馈误差处理的跨导电压放大器,用来产生正比于输入电压的电流指令的电流基准发生器,电流检测(PWM)比较器,PWM逻辑和用来驱动外接FET的图腾柱驱动器.此外,控制器还提供峰值电流限制,重起定时器,过压保护(OVP)以及使能等. UCC28810和UCC28811广泛用在交流输入HB LED照明,工业,商业和住宅区照明以及户外照明如路灯,停车场,建筑物和装饰性LED照明等.本文介绍了UCC28810和UCC28811的主要特性,方框图, 简化应用电路图, 25W PFC反激转换器参考设计以及PR788 100W AC/DC LED电流驱动器参考设计和元件列表.
The UCC28810 and UCC28811 are general lighting power controllers for low to medium power lumens applications requiring power factor correction and EMC compliance. It is designed for controlling a flyback, buck or boost converter operating in critical conduction mode. It features a transconductance voltage amplifier for feedback error processing, a simple current reference generator for generating a current command proportional to the input voltage, a current-sense (PWM) comparator, PWM logic and a totem-pole driver for driving an external FET.
In the critical conduction mode operation, the PWM circuit is self-oscillating with the turn-on being governed by a transformer zero energy detector (TZE pin) and the turn-off being governed by the current sense comparator. Additionally, the controller provides features such as peak current limit, restart timer, overvoltage protection (OVP), and enable.
The efficient system performance is attained by incorporation of zero power detect function which allows the controller output to shut down at light load conditions without running into overvoltage. The device also features an innovative slew rate enhancement circuit which improves the large signal transient performance of the voltage error amplifier. The low start-up and operating currents of the device result in low power consumption and ease of start-u...