MAX17075EVKIT+: 3Ch + Power Amp, LCD TFT Supply

The MAX17075 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that provides the voltages and features required for active matrix thin-film transistor (TFT), liquid-crystal display (LCD) panels in LCD monitors and LCD TVs.

The EV kit contains a step-up switching regulator, a two-stage positive charge pump for the TFT gate-on supply, a single-stage negative charge pump for the TFT gate-off supply, and a high-current op amp. Also included is a logic controlled high-voltage switch array, with capacitor control delay, for the positive gate-driver supply. A capacitive dummy load is provided at the high-voltage switch output for ease of testing without an attached panel.

The MAX17075 EV kit is designed to operate from a DC supply voltage of +2.5 V to +5.5 V. At +5 V (±10%) nominal input voltage, the step-up switching regulator provides a +13 V output and up to 500 mA. The positive charge pump provides a +30 V output and up to 30 mA. The negative charge pump provides a -7 V output and up to 60 mA. The high-current op amp provides a +6.5 V output that can source or sink 500 mA peak current. The high-voltage switch array is controlled by external logic.

The MAX17075 switches at 1.2 MHz, allowing the use of tiny surface-mount components. The MAX17075 thin QFN package (0.8 mm maximum height) with low-profile external components allows this circuit to be less than 3 mm high.