SR087中文资料Adjustable Off-line Inductorless Switching Regulator数据手册Microchip规格书

描述 Description

SR087 is an inductorless switching regulator designed to operate directly from a rectified AC line. The operating principle is to turn on a pass transistor when the rectified AC is below the output voltage, and to turn it off when the output voltage reaches a specific level. A linear regulator supplied by VOUT provides an additional fixed 5.0V output. Efficiencies of around 55% may be realized for loads up to 1.0W in 120VAC applications, with around 50% efficiencies for loads up to 800mW in 230VAC applications.A logic-level enable input allows the SR087 to be disabled – useful when it is employed as a keep-alive power supply.WARNING! Galvanic isolation is not provided. Dangerous voltages are present when connected to the AC line. It is the responsibility of the designer employing the SR087 to ensure adequate safeguards are in place to protect the end user from electrical shock.The circuits shown in this datasheet are not guaranteed to meet surge and conducted EMI requirements. The effectiveness of these circuits may vary with a particular application. The designer should conduct tests to ascertain compliance with applicable standards and regulations.

特性 Features

Efficient operation without magnetics
No high voltage capacitors
Adjustable main output voltage (9.0 to 50V)
Additional 5.0V internal regulator
Up to 100mA combined output current
Single BOM for 120VAC/230VAC
Built-in soft start
Less than 200mW standby power

简介

SR087属于集成电路（IC）的ACDC转换器离线开关。由制造生产的SR087AC DC 转换器，离线开关该系列是元器件级控制产品，用于构建将交流市电转换为直流电（通常电压大幅降低）的设备。集成和未集成系统主要开关元件的器件均包括在内。由于高输入输出电压比，以及此类系统中通常需要隔离，这些器件通常与外部变压器配合使用。尽管通常使用定制变压器来实现此用途，但也有许多专门用于此用途的库存产品，请参见“开关转换器，SMPS 变压器”标题。