IS31LT3957A - Lumissil

IS31LT3957A HIGH VOLTAGE LED LIGHTING CONTROLLER

The IS31LT3957A is a current mode PWM controller designed to drive a low side external NMOS FET for wide input/output voltage range and high LED current applications. An external resistor senses the high side output current of the LED string. A high side sense is the most flexible current sensing scheme, since it functions in either boost or buck-boost mode .

Features

 Wide high voltage input range: 5V to 75V
 Supports boost, buck-boost, SEPIC and buck topology
 ±2% output current accuracy
 Adjustable operating frequency range of 100kHz~1MHz
 Programmable soft start to avoid inrush current
 Fixed under voltage lockout threshold
 EMI reduction capabilities - Programmable spread spectrum function - Operating frequency synchronization with external clock source
 Supports either analog or PWM dimming
 Fault protection with reporting: - VCC under voltage lockout (not reported) - Programmable output over voltage protection - Output short circuit protecti.