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.
Features
- 8V to 30V Input Voltage
- 50 kHz to 800 kHz Programmable Switching Frequency
- Adaptive Boost Output to White LED Voltage
- High Precision PWM Dimming Resolution up to 5000:1
- Programmable Over-voltage Protection Threshold at Output
- Programmable Under-voltage Threshold at Input with Adjustable Hysteresis
- Adjustable Soft Start Time Independent of Dimming Duty Cycle
- Built-in LED Open Protection
- Built-in Schottky Diode Open/Short Protection
- Built-in IFB Short Protection
- Thermal Shutdown
- 16L SOIC Package