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.

簡介

SG1845Y屬于集成電路（IC）的PMIC-穩(wěn)壓器-DCDC開關(guān)式控制器。由制造生產(chǎn)的SG1845YDC-DC 開關(guān)控制器PMIC（電源管理集成電路）DC 到 DC 開關(guān)式控制器是用于高效率電路的穩(wěn)壓 IC，其配置為生成高于（突升或步升）或低于（突降或步降）輸入電源的輸出電源電壓。其他拓?fù)浣Y(jié)構(gòu)可能包括：降壓-升壓、反激、正激、Cuk、SEPIC、全橋、半橋和推挽式。這些器件不同于需要最小電壓并“燒盡”多余電壓的線性穩(wěn)壓器。