The TPS61180/1/2 ICs provide highly integrated solutions for media size LCD backlight. These devices have a built-in high efficiency boost regulator with integrated 1.5A/40V power MOSFET. The six current sink regulators provide high precision current regulation and matching. In total, the device can support up to 60 WLED. In addition, the boost output automatically adjusts its voltage to the WLED forward voltage to improve efficiency.
The devices support pulse width modulation (PWM) brightness dimming. During dimming, the WLED current is turned on/off at the duty cycle and frequency determined by the PWM signal input on the DCRTL pin. One potential issue of PWM dimming is audible noises from the output ceramic capacitors. The TPS61180/1/2 family is designed to minimize this output AC ripple across a wide dimming duty cycle and frequency range; therefore, reducing the audible noise.
The TPS61180/1/2 ICs provide a driver output for an external PFET connected between the input and inductor. During short circuit or over-current conditions, the ICs turn off the external PFET and disconnect the battery from the WLEDs. The PFET is also turned off during IC shutdown (true shutdown) to prevent any leakage current of the battery. The device also integrates over-voltage protection, soft-start and thermal shutdown.
The TPS61180 IC requires external 3.3V IC supply, while TPS61181 and TPS61182 ICs have a built-in linear regulator for the IC supply. All the devices are in a 3×3 mm QFN package.