HV9910B

Features

Switch mode controller for single switch LED drivers

Enhanced drop-in replacement to the HV9910

Open loop peak current controller

Internal 8.0 to 450V linear regulator

Constant frequency or constant off-time operation

Linear and PWM dimming capability

Requires few external components for operation

Applications

DC/DC or AC/DC LED driver applications

RGB backlighting LED driver

Back lighting of flat panel displays

General purpose constant current source

Signage and decorative LED lighting

Chargers

►

►

►

►

►

►

►

►

►

►

►

►

►

General Description

The HV9910B is an open loop, current mode, control LED

driver IC. The HV9910B can be programmed to operate in

either a constant frequency or constant off-time mode. It

includes an 8.0 - 450V linear regulator which allows it to work

from a wide range of input voltages without the need for an

external low voltage supply. The HV9910B includes a PWM

dimming input that can accept an external control signal with a

duty ratio of 0 - 100% and a frequency of up to a few kilohertz.

It also includes a 0 - 250mV linear dimming input which can

be used for linear dimming of the LED current.

The HV9910B is ideally suited for buck LED drivers. Since

the HV9910B operates in open loop current mode control, the

controller achieves good output current regulation without the

need for any loop compensation. PWM dimming response is

limited only by the rate of rise and fall of the inductor current,

enabling very fast rise and fall times. The HV9910B requires

only three external components (apart from the power stage)

to produce a controlled LED current making it an ideal solution

for low cost LED drivers.

Typical Application Circuit

Universal High Brightness

LED Driver

L1

Q1

D1

HV9910B

VIN

GATE

PWMD

VDD

LD

CS

RT

GND