D1

IDRV

ISNS

VIN

VDD

AGND

TPS61197

GDRV

FSW

VIN = 24V

OVP

R3

EN

R10

R6

C6

C5

PGND

COMP

R5

UVLO

FAULT

C3

1.0uF

R7

REF

R1

R2

22uF

C7

C2

2.2uF

300k

2.2uF

PWM

IFB

50k

22nF

C4

R4

Q1

1nF

C1

10nF

R8

3

0.1

220pF

300

1.0M

20k

EC2

EC1

470uF

383k

24.9k

1.0

R9

L1

68uH

R11

100

C8

Q2

R12

1.0k

1.0nF

TPS61197

www.ti.com

SLVSC25 – JULY 2013

Single-String WLED Driver for LCD TV

Check for Samples: TPS61197

1

FEATURES

•

Adjustable Soft Start Time Independent of

Dimming Duty Cycle

•

8V to 30V Input Voltage

•

Built-in LED Open Protection

•

50 kHz to 800 kHz Programmable Switching

•

Built-in Schottky Diode Open/Short Protection

Frequency

•

Built-in IFB Short Protection

•

Adaptive Boost Output to White LED Voltage

•

Thermal Shutdown

•

High Precision PWM Dimming Resolution up

to 5000:1

•

16L SOIC Package

•

Programmable Over-voltage Protection

APPLICATIONS

Threshold at Output

•

Programmable Under-voltage Threshold at

•

LCD TV Backlight

Input with Adjustable Hysteresis

DESCRIPTION

The TPS61197 provides highly integrated solutions for LCD TV backlight. This device is a current mode boost

controller driving one WLED string with multiple LEDs in series. The input voltage range for TPS61197 is from 8V

to 30V.The TPS61197 adjusts the boost controller’s output voltage automatically to provide only the minimum

voltage required by the LED string to generate the setting LED current, thereby optimizing the driver’s efficiency.

Its switching frequency is programmed by an external resistor from 50 kHz to 800 kHz.

The TPS61197 supports direct PWM brightness dimming method. During the PWM dimming, the white LED

current is turned on and off at the duty cycle and frequency which are determined by an external PWM signal.

The PWM dimming frequency ranges from 90 Hz to 22 kHz.

The TPS61197 integrates over-current protection, output short circuit protection, Schottky diode open and short

protection, LED open protection, LED string short protection and over temperature shutdown circuit. The device

also provides programmable input under-voltage lockout threshold and output over-voltage protection threshold.

The TPS61197 has a built-in linear regulator which steps down the input voltage to the VDD voltage for powering

the internal circuitry. An internal soft start circuit is implemented to work with an external capacitor to adjust the

soft startup time to minimize the in-rush current during boost converter startup. The device is available in 16-pin

SOIC package, which is ideal for a single-layer PCB board.

SIMPLIFIED SCHEMATIC CIRCUIT

Figure 1. Typical Application of TPS61197

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 © 2013, 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.