RFPWM

/MODE

L1

10uH

D1

C3

4.7uF

IFB1

IFB2

IFB3

IFB4

OVC

VIN

VDDIO

ISET

AGND

TPS61187

C2

1.0 uF

SW

FSLCT

C1

2.2uF

PGND

4.5V~24V

R4

R5

EN

PWM

R1

62 KW

R3

499 KW

19.8 mA

IFB5

IFB6

FAULT

FPO

VDD_GPIO

R7

1.2 KW

R8

10 KW

R2

9.09 KW

Open

Open

TPS61187

www.ti.com

SLVSA85D – JUNE 2010 – REVISED FEBRUARY 2012

WLED Driver for Notebooks with PWM Interface and Auto Phase Shift

Check for Samples: TPS61187

1

FEATURES

DESCRIPTION

The TPS61187 IC provides a highly integrated WLED

•

4.5 V to 24 V Input Voltage

driver solution for notebook LCD backlight. This

•

38 V Maximum Output Voltage

device has a built-in high efficiency boost regulator

•

Integrated 2 A 40 V MOSFET

with integrated 2.0A /40V power MOSFET. The six

current sink regulators provide high precision current

•

300 kHz to 1 MHz Programmable Switching

regulation and matching. In total, the device can

Frequency

support up to 60 WLEDs. In addition, the boost output

•

Adaptive Boost Output to WLED Voltages

automatically adjusts its voltage to the WLED forward

•

Wide PWM Dimming Frequency Range

voltage to optimize efficiency.

–

100 Hz to 50 KHz for Direct PWM Mode

The

TPS61187

supports

the

auto

phase

shift

–

100 Hz to 22 KHz for Frequency

dimming method and direct PWM dimming method.

During phase shift PWM dimming, the WLED current

Programmable Mode

is turned on/off at the duty cycle controlled by the

•

100:1 Dimming Ratio at 20 kHz

input PWM signal and each channel is shifted

•

10000:1 Dimming Ratio at 200 Hz (Direct PWM

according

to

the

frequency

determined

by

an

mode)

integrated pulse width modulation (PWM) signal. The

frequency of this signal is resistor programmable,

•

Small External Components

while the duty cycle is controlled directly from an

•

Integrated Loop Compensation

external PWM signal input to the PWM pin. During

•

Six Current Sinks of 30 mA Max

direct PWM dimming, the WLED current is turned

•

1.5% (Typ) Current Matching

on/off synchronized with the input PWM signal.

•

PWM Brightness Interface Control

•

PWM Phase Shift Mode Brightness Dimming

Method or Direct PWM Dimming Method

•

4 kV HBM ESD Protection

•

Programmable Over Voltage Threshold

•

Built-in WLED Open/Short Protection

•

Thermal Shutdown

•

20 Lead 4mm × 4mm × 0.8 mm TQFN Package

APPLICATIONS

•

Notebook LCD Display Backlight

Figure 1. Typical Application – Phase Shift PWM

Mode

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Copyright © 2010–2012, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.