Overview
The TPS61196PWPT from Texas Instruments is a highly integrated LED driver IC designed specifically for LCD TV backlight applications. This device is a current mode boost controller capable of driving up to six WLED strings, each with multiple LEDs in series. It features independent PWM dimming for each string, allowing for precise brightness control. The TPS61196PWPT operates within an input voltage range of 8V to 30V and can adjust the boost controller's output voltage to optimize efficiency based on the LED string with the largest forward voltage drop.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Input Voltage Range | 8 - 30 | V |
| Output Voltage | Up to 120 | V |
| Switching Frequency | 100 kHz - 800 kHz | Hz |
| LED Current per String | 50 mA - 400 mA | mA |
| Current Matching Accuracy | ±1.5% | % |
| PWM Dimming Frequency | 90 Hz - 22 kHz | Hz |
| Package Type | 28-pin HTSSOP with PowerPAD | |
| Operating Junction Temperature | -40°C to 125°C | °C |
| Thermal Resistance (Junction-to-Ambient) | 33.8 | °C/W |
Key Features
- Independent PWM dimming for each of the six WLED strings.
- Adjustable LED current from 50 mA to 400 mA with ±1.5% matching accuracy.
- Programmable switching frequency from 100 kHz to 800 kHz using an external resistor.
- Adaptive boost output voltage to optimize efficiency based on the LED string with the largest forward voltage drop.
- Integrated protections including overcurrent, output short circuit, ISET short to ground, diode open and short, LED open and short, and overtemperature shutdown.
- Programmable input undervoltage lockout threshold and output overvoltage protection threshold.
- Built-in linear regulator and soft-start circuit to minimize in-rush current during startup.
- High precision PWM dimming resolution up to 5000:1.
- Built-in LED open and short protection, and Schottky diode open/short protection.
Applications
- LCD TV backlight systems.
- Scan mode LCD TV backlight systems.
Q & A
- What is the input voltage range of the TPS61196PWPT?
The input voltage range is from 8V to 30V.
- How many WLED strings can the TPS61196PWPT drive?
The device can drive up to six WLED strings.
- What is the adjustable LED current range per string?
The LED current per string is adjustable from 50 mA to 400 mA.
- What is the switching frequency range of the TPS61196PWPT?
The switching frequency can be programmed from 100 kHz to 800 kHz using an external resistor.
- Does the TPS61196PWPT support PWM dimming?
Yes, it supports direct PWM brightness dimming with a frequency range from 90 Hz to 22 kHz.
- What kind of protections does the TPS61196PWPT have?
The device includes 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.
- What is the package type of the TPS61196PWPT?
The device is available in a 28-pin HTSSOP package with PowerPAD.
- What is the operating junction temperature range of the TPS61196PWPT?
The operating junction temperature range is from -40°C to 125°C.
- Does the TPS61196PWPT have built-in protection for the IFB pin?
Yes, it can detect the IFB pin short to ground to protect the LED string.
- How does the TPS61196PWPT optimize driver efficiency?
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.
