TI TPS61196PWPR

The TPS61196 provides a highly integrated solution for LCD TV backlighting, featuring independent PWM brightness adjustment for each string. This device is a current-mode boost controller capable of driving up to six WLED strings composed of multiple LEDs connected in series. Each string has an independent current regulator, providing adjustable LED current in the range of 50mA to 400mA (matching accuracy ±1.5%). The minimum voltage on the sink current can be set in the range of 0.3V to 1.0V to meet different LED current settings. The input voltage range of the TPS61196 is between 8V and 30V.

The TPS61196 automatically adjusts the output voltage of the boost controller to provide only the voltage required by the LED strings, which is the maximum forward voltage drop plus the required minimum voltage on the IFB pin of that string, thereby optimizing the efficiency of the driver. Its switching frequency can be set between 100kHz and 800kHz through an external resistor.

The TPS61196 supports direct PWM brightness adjustment. Each string has an independent PWM control input. During PWM brightness adjustment, the LED current is turned on and off in terms of frequency and duty cycle (determined by an external PWM signal). The PWM frequency range is between 90kHz and 22kHz.

The TPS61196 integrates overcurrent protection, output short-circuit protection, ISET short-circuit to ground protection, diode open-circuit and short-circuit protection, LED open-circuit and short-circuit protection, and an over-temperature shutdown circuit. In addition, the TPS61196 can detect a short-circuit of the IFB pin to ground to protect the LED strings. This device also provides programmable input undervoltage lockout thresholds and output overvoltage protection thresholds.

The TPS61196 has a built-in linear regulator that steps down the input voltage to the VDD voltage to power the internal circuits. An internally implemented soft-start circuit works with an external capacitor to adjust the soft-start time, significantly reducing the inrush current during the startup of the boost converter. This device is packaged in a 28-pin HTSSOP with PowerPAD, providing good thermal performance.

• 8V to 30V input voltage
• Up to 120V output voltage
• 100kHz to 800kHz programmable switching frequency
• Adaptive boost output for LED voltage
• Six current sinks, 200mA continuous output / 400mA pulsed output per LED string
• ±1.5% current matching between LED strings
• High-accuracy PWM dimming with up to 5000:1 resolution
• Programmable overvoltage threshold on output and each current sink
• Programmable undervoltage threshold on input with adjustable hysteresis
• Adjustable soft-start time independent of dimming duty cycle
• Built-in LED open/short circuit protection
• Built-in Schottky diode open/short circuit protection
• Built-in ISET short circuit protection
• Built-in IFB short circuit protection
• Thermal protection
• 28L HTSSOP package with PowerPAD

• LCD TV backlight scanning mode
• LCD TV backlight