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HT7L4091

Universal Step-Down PWM Control

For High Brightness LED Lighting Control

Features

● Input supply AC voltage range: 100V~240V

● Ultra Low Power-on Start-up current < 30μA

● Integrated 25V Zener diode internally connected to VIN pin

● 5V LDO output voltage with 6mA driving current for external components

● Frequency jitter function for enhanced EMI performance

● Efficiency > 85%

● Under Voltage Lockout Function - UVLO

● Current mode operation with cycle-by-cycle current limiting

● Over Temperature Protection Function

● High-current FET Drive Output

● Linear and PWM Dimming Function

● Enhanced Short Circuit Protection Function

Applications

● AC/DC and DC/DC Power control For High Power LED Lighting

● RGB back lighting LED driver

● Flat Panel Displays Back Lighting

● General Purpose Constant Current Source

● Signage and Decorative LED lighting

● Battery Chargers

General Description

The HT7L4091 device provides a low-cost solution for active current mode PWM controls of High

Intensity LED drive systems supplied by either AC or DC line power lines. The device operates

in constant off-time mode which is suitable for buck LED drivers. The low start-up and operating

currents provides flexible power requirements for high efficiency or low cost applications. The

switch frequency off-time can be programmed using an external resistor. The peak current mode

control achieves good output current regulation without requiring loop compensations for a wide

range of input voltages.

Included in the device is a PWM dimming input which can accept an external control signal with a

duty ratio from 0 to 100%. The output current can be programmed from 0 to 250mA by applying an

external control voltage on the linear dimming control input.

The device includes a frequency jitter function which helps to reduce EMI power supply emissions.

from damage should the LEDs be short circuited. .

The device requires a minimum number of external standard components and is available in an 8-pin

NSOP package for small area PCB applications.