1 Features

1• 8-V to 30-V Input Voltage

• Up to 120-V Output Voltage

• 100-KHz to 800-kHz Programmable Switching

Frequency

• Adaptive Boost Output for LED Voltages

• Six Current Sinks, 200-mA Continuous Output,

400-mA Pulse Output for Each String

• ±1.5% Current Matching Between Strings

• High Precision PWM Dimming Resolution up to

5000:1

• Programmable Overvoltage Threshold at Output

and Each Current Sink

• Programmable Undervoltage Threshold at Input

with Adjustable Hysteresis

• Adjustable Soft Start Time Independent of

Dimming Duty Cycle

• Built-in LED Open and LED Short Protection

• Built-in Schottky Diode Open/Short Protection

• Built-in ISET Short Protection

• Built-in IFB Short Protection

• Thermal Shutdown

2 Applications

• LCD TV Backlight

• Scan Mode LCD TV Backlight

3 Description

The TPS61196 provides a highly integrated solution

for LCD TV backlight with an independent PWM

dimming function for each string. This device is a

current mode boost controller driving up to six WLED

strings with multiple LEDs in series. Each string has

an independent current regulator providing a LED

current adjustable from 50 mA to 400 mA within

±1.5% matching accuracy. The minimal voltage at the

current sink is programmable in the range of 0.3 V to

1 V to fit with different LED current settings. The input

voltage range for the device is from 8 V to 30 V.

The device adjusts the boost controller's output

voltage automatically to provide only the voltage

required by the LED string with the largest forward

voltage drop plus the minimum required voltage at

that string's IFB pin, thereby optimizing driver

efficiency. Its switching frequency is programmed by

an external resistor from 100 kHz to 800 kHz.

The TPS61196 supports direct PWM brightness

dimming. Each string has an independent PWM

control input. During the PWM dimming, the LED

current is turned on or turned off at the frequency and

duty cycle which are determined by the external

PWM signal. The PWM frequency ranges from 90 Hz

to 22 kHz.

The device integrates overcurrent protection, output

short-circuit protection, ISET short-to-ground

protection, diode open and short protection, LED

open and short protection, and overtemperature

shutdown circuit. In addition, the TPS61196 can

detect the IFB pin short to ground to protect the LED

string. The device also provides programmable input

undervoltage lockout threshold and output overvoltage protection threshold.

The TPS61196 has a built-in linear regulator which

steps down the input voltage to the VDD voltage for powering the internal circuitry. An soft-start circuit is

implemented internally to work with an external

capacitor to adjust the soft start-up time to minimize

the in-rush current during boost converter start-up.

The device is available in a 28-pin HTSSOP package with PowerPAD™.