1.

General description

The UBA3077HN is a high efficiency LED driver in an HVQFN40 package for general LED

lighting or backlighting LCD displays.

Operating from a supply of 10 V to 42 V, it can drive up to 3 strings of 20 LEDs each. The

low voltage circuitry is powered by an external 5 V voltage supply.

The peak current in each string is fixed by an external resistor. Three independent

Pulse-Width Modulated (PWM) signals are available for dimming purposes. These PWM

signals are delivered either directly by the graphic processor (direct control mode) to the

pins PWM1, PWM2 and PWM3, or generated on-board based on data sent via the

Each LED string is supplied by its own boost converter delivering an output voltage from

A power saving mode is entered when all PWM signals stay LOW for a period longer than

1s.

Several protection mechanisms are available: overvoltage, short-circuit and open LED,

overcurrent, UnderVoltage LockOut (UVLO) and overtemperature with an advanced

adaptive protection. An error self-recovery (hiccup) mechanism is available with

programmable delay time via an external capacitor.

2.

Features and benefits

UBA3077HN

Three-channel switched-mode LED driver

Rev. 1 — 8 February 2011

Objective data sheet

Three-channel LED backlight driver

Up to 150 mA per channel

±2 % absolute LED current accuracy

and channel-to-channel matching

Peak LED current programmable with

external resistor

External power supply voltage from 10 V

to 42 V and 5 V for low voltage circuitry

75 V output voltage

Constant 500 kHz frequency peak

current mode control

High efficiency up to 90 %

Low value output capacitor (2

μF)

14-bit PWM dimming (either defined by

system-generated PWMs, or internally

generated) from 2.0 kHz to 24 kHz (duty

cycle from 0.1 % to 100 %)

Accurate internal oscillator

All power FETs integrated