SG3845中文资料Current Mode PWMs Isolated Switching Reg Low Start-Up Current (<1mA) 0°C to70°C数据手册Microchip规格书

描述 Description

The SG1844/45 family of control ICs provides all the required 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 Nchannel 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 SG3844/45 is designed for the commercial range of 0°C to 70°C.

特性 Features

Optimized For Off-Line Control
Low Start-Up Current (Automatic Feed Forward Compensation
Trimmed Oscillator Discharge Current
Pulse-By-Pulse Current Limiting
Enhanced Load Response Characteristics -Undervoltage Lockout with 6V Hysteresis
Double-Pulse Suppression
High-Current Totem-Pole Output (1A Peak)
Internally Trimmed Band-gap Reference
500kHz Operation SG1845 - 8.4 Volts
Low Shoot-Through Current <75mA Over Temperature

简介

SG3845属于集成电路（IC）的PMIC-稳压器-DCDC开关式控制器。由制造生产的SG3845DC-DC 开关控制器PMIC（电源管理集成电路）DC 到 DC 开关式控制器是用于高效率电路的稳压 IC，其配置为生成高于（突升或步升）或低于（突降或步降）输入电源的输出电源电压。其他拓扑结构可能包括：降压-升压、反激、正激、Cuk、SEPIC、全桥、半桥和推挽式。这些器件不同于需要最小电压并“烧尽”多余电压的线性稳压器。