© 2012 Semtech Corporation

POWER MANAGEMENT

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SC5012

High Efficiency 4-Ch, 150mA/Ch LED Driver with

Revision 2.2

Features

Input Voltage — 4.75V to 45V

Output Voltage — Up to 65V

Step-up (Boost) Controller

Ultra-Fast Transient Response

Programmable Switching Frequency

External Sync Frequency for Boost Controller

Linear Current Sinks

4 Strings, up to 150mA/String

Current Matching ±1%

Current Accuracy ±2%

PWM Dimming

String-by-String Phase Shifting

Dimming Frequency 100Hz-30kHz

User Selectable 9 or 10 Bits Dimming Resolution

Optional Synchronization to VSYNC/HSYNC Signal

External Frequency Synchronization, FSYNC

8-bit Analog Dimming

Fault Status — Open/Short LED, OTP

Device Control: SYNC Freq, PLL Setting

Protection Features

Open/Shorted LED(s) and adjustable OVP

Over-Temperature

4mm X 4mm 24 Ld QFN Package

Applications

Medium-sized LCD Panel

Automotive Car Navigation/Information Display

LCD Monitors

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Description

The SC5012 is a 4-channel high-precision, high-efficiency

step-up (Boost) HB LED driver designed for backlight

applications. It features wide input voltage range (4.75V to

45V) , flexible output configuration, wide analog and PWM

dimming range, phase shifting, optional fading, external

interface, and numerous protection features.

The boost controller, with programmable switching fre-

quency from 200kHz to 2.2MHz, can maximize efficiency

by dynamically minimizing the output voltage while

maintaining LED string current accuracy. It provides excel-

lent line and load response with no external compensa-

tion components. Each linear current sink is matched

within ±1% for superb lighting uniformity, and the accu-

racy of each string current is ±2%. An external resistor

adjusts the current from 40-150mA per string. It also fea-

tures PWM dimming resolution of 9 or 10 bits (user select-

able) over a dimming frequency from 100Hz to 20kHz,

synchronized to the SYNC signal or the boost oscillator.

String-by-string phase shifting reduces the demand on

the input/output capacitance, decreases EMI, and

improves dimming linearity.

SC5012 is available in 4mm X 4mm 24 Ld QFN package.

Typical Application Circuit

DRVN

CS

AG ND

ISET

FSET

CPLL

SCP

VIN

SC 5012

PW M I

PW M I

R15

R4

R5

FLT

C21

VLDO

FLT

VCC

SS

SDA

PG ND

R8

R7

C4

R6

R 9

Q 1

C 1

L1

SYNC

SYNC

O VP

R10

R11

to 65V

Up to

150m A/CH

SCL

IO 1

IO 2

IO 3

C 6

IO 4

FSYNC

FSYNC

EN

C22

R24

C20

VLDO