描述 Description

This primary controller I.C., developed in BCD60II technology, has been designed to implement off line or DC-DC power supply applications using a fixed frequency current mode control.

Based on a standard current mode PWM controller this device includes some features such as programmable soft start, IN/OUT synchronization, disable (to be used for over voltage protection and for power management), precise maximum Duty Cycle Control, 100ns leading edge blanking on current sense, pulse by pulse current limit, overcurrent protection with soft start intervention, and Standby function for oscillator frequency reduction when the converter is lightly loaded.

特性 Features

? PRIMARY OVERCURRENT FAULT DETECTION WITH RE-START DELAY
? PROGRAMMABLE SOFT START
? IN/OUT SYNCHRONIZATION
? PWM UVLO WITH HYSTERESIS
? INTERNAL 100ns LEADING EDGE BLANKING OF CURRENT SENSE
? LATCHED DISABLE
? PACKAGE: DIP16 AND SO16
? 100% AND 50% MAXIMUM DUTY CYCLE LIMIT
? PROGRAMMABLE DUTY CYCLE
? CURRENT-MODE CONTROL PWM
? LOW START-UP CURRENT (< 120μA)
? SWITCHING FREQUENCY UP TO 1MHz
? FULLY LATCHED PWM LOGIC WITH DOUBLE PULSE SUPPRESSION
? STANDBY FUNCTION
? HIGH-CURRENT OUTPUT DRIVE SUITABLE FOR POWER MOSFET (1A)

簡(jiǎn)介

L5991屬于集成電路（IC）的ACDC轉(zhuǎn)換器離線開關(guān)。由制造生產(chǎn)的L5991AC DC 轉(zhuǎn)換器，離線開關(guān)該系列是元器件級(jí)控制產(chǎn)品，用于構(gòu)建將交流市電轉(zhuǎn)換為直流電（通常電壓大幅降低）的設(shè)備。集成和未集成系統(tǒng)主要開關(guān)元件的器件均包括在內(nèi)。由于高輸入輸出電壓比，以及此類系統(tǒng)中通常需要隔離，這些器件通常與外部變壓器配合使用。盡管通常使用定制變壓器來(lái)實(shí)現(xiàn)此用途，但也有許多專門用于此用途的庫(kù)存產(chǎn)品，請(qǐng)參見“開關(guān)轉(zhuǎn)換器，SMPS 變壓器”標(biāo)題。