ST 公司的VIPER28是离线高压电源转换器,具有800V功率部分,PWM控制,两级过流保护,以及过压和过载保护,滞后的热保护,软起动和故障消除后的自动重起功能.突发模拟工作和非常低功耗(265Vac时为50 mW )满足待机功耗的严格要求. VIPER28主要用作消费类电子和家用电器的电源,ATX辅助电源,中小功率AC/DC适配器,以及STB,DVD播放器,白色家电的开关电源.本文介绍了VIPER28的主要特性,方框图以及简单特性的反激应用框图和满特性的反激应用框图.
VIPER28 Off-line high voltage converters
The device is an off-line converter with an 800 V rugged power section, a PWM control, two levels of over-current protection, over-voltage and overload protections, hysteretic thermal protection, soft-start and safe auto-restart after any fault condition removal. Burst mode operation and device very low consumption helps to meet the standby energy saving regulations. Advance frequency jittering reduces EMI filter cost. The extra power timer allows the management of output peak power for a designed time window. The high voltage start-up circuit is embedded in the device
VIPER28主要特性:
800 V avalanche rugged power section
PWM operation with frequency jittering for low EMI
Operating frequency:
– 60 kHz for L type
– 115 kHz for H type
Standby power < 50 mW at 265 VAC
Limiting current with adjustable set point
Adjustable and accurate over-voltage protection
On-board soft-start
Safe auto-restart after a fault condition
Hysteretic thermal shutdown
Delayed overload protection
VIPER28应用:
Auxiliary power supply for consumer and home equipment
ATX auxiliary power supply
Low / medium power AC-DC adapters
SMPS for set-top boxes, DVD players and recorders, white goods
图1.VIPER28典型拓扑图
图2.VIPER28方框图
图3.VIPER28简单特性反激应用框图
图4. VIPER28满特性反激应用框图
