The TPS61185 IC provides highly integrated solutions for large-size LCD backlighting. This device has a built-in high efficiency boost regulator with integrated 2 A/40 V power MOSFET. The eight current sink regulators provide high precision current regulation and matching. In total, the device can support up to 80 LEDs. In addition, the boost output automatically adjusts its voltage to the WLED forward voltage to improve efficiency.
The TPS61185 supports the PWM method for brightness dimming. Simply tie the unused current sinks to ground if fewer than eight are needed. During PWM dimming, each of the eight current regulators is turned on/off at the duty cycle determined by an external pulse width modulation (PWM) signal input to the PWM pin. The frequency at which each current regulator turns on/off follows the input PWM signal on the PWMIN pin if the MODE pin is grounded. If the MODE pin is left floating or tied high, the regulators turn on/off at the frequency programmed by an external resistor on the FPWMO pin.
The TPS61185 IC supports boost switch frequency programming from 600kHz to 2MHz by an external resistor on the FSW pin. The device also provides a driver output for an optional external PFET connected between the input and inductor for truly disconnecting the battery from LED during the shutdown or fault protection. The device integrates resistor programmable over-voltage protection, soft-start, and thermal shutdown.
The TPS61185 IC has a built-in linear regulator to power the internal circuits of the IC. The device is in a 4 mm × 4 mm QFN package.