SG1844Y数据手册集成电路（IC）的ACDC转换器离线开关规格书PDF

描述 Description

Features:
• OPTIMIZED FOR OFF-LINE CONTROL
• LOW START-UP CURRENT (<1mA)
• AUTOMATIC FEED FORWARD COMPENSATION
• TRIMMED OSCILLATOR DISCHARGE CURRENT
• PULSE-BY-PULSE CURRENT LIMITING
• ENHANCED LOAD RESPONSE CHARACTERISTICS
• HYSTERESIS (SG1844 only)
• DOUBLE PULSE SUPPRESSION
• HIGH-CURRENT TOTEM-POLE OUTPUT
• INTERNALLY TRIMMED BANDGAP REFERENCE
• 500kHz OPERATION
• UNDERVOLTAGE LOCKOUT SG1844 - 16 volts SG1845 - 8.4 volts
• LOW SHOOT-THROUGH CURRENT <75mA OVER TEMPERATURE The SG1844/45 family of control ICs provides all the necessary features to implement off-line fixed frequency, current-mode switching power supplies with a minimum number of external components. Current-mode architecture demonstrates improved line regulation, improved load regulation, pulse-by-pulse current limiting and inherent protection of the power supply output switch. The bandgap reference is trimmed to ±1% over temperature. Oscillator discharge current is trimmed to less than ±10%. The SG1844/45 has under-voltage lockout, current-limiting circuitry and start-up current of less than 1mA. The totem-pole output is optimized to drive the gate of a power MOSFET. The output is low in the off state to provide direct interface to an N-channel device. Both operate up to a maximum duty cycle range of zero to <50% due to an internal toggle flip-flop which blanks the output off every other clock cycle. The SG1844/45 is specified for operation over the full military ambient temperature range of -55°C to 125°C. The SG2844/45 is specified for the industrial range of -25°C to 85°C, and the SG3844/45 is designed for the commercial range of 0°C to 70°C.

简介

SG1844Y属于集成电路（IC）的ACDC转换器离线开关。由制造生产的SG1844YAC 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。