The MAX749 generates negative LCD-bias contrast voltages from 2V to 6V inputs. Full-scale output voltage can be scaled to -100V or greater, and is digitally adjustable in 64 equal steps by an internal digital-to-analog converter (DAC). Only seven small surface-mount components are required to build a complete supply. The output voltage can also be adjusted using a PWM signal or a potentiometer.
A unique current-limited control scheme reduces supply current and maximizes efficiency, while a high switching frequency (up to 500kHz) minimizes the size of external components. Quiescent current is only 60µA max and is reduced to under 15µA in shutdown mode. While shut down, the MAX749 retains the voltage set point, simplifying software control. The MAX749 drives either an external P-channel MOSFET or a PNP transistor.
Notes: **This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
duties, taxes, fees, and exchange rates. For volume-specific prices
and delivery, please see the price and availability page
or contact an authorized distributor.