MC34270

Order this document by MC34270/D Liquid Crystal Display and Backlight Integrated Controller The MC34270 and MC34271 are low power dual switching voltage regulators, specifically designed for handheld and laptop applications, to provide several regulated output voltages using a minimum of external parts. Two uncommitted switching regulators feature a very low standby bias current of 5.0 µA, and an operating current of 7.0 mA capable of supplying output currents in excess of 200 mA. Both devices have three additional features. The first is an ELD Output that can be used to drive a backlight or a liquid crystal display. The ELD output frequency is the clock divided by 256. The second feature allows four additional output bias voltages, in specific proportions to VB, one of the switching regulated output voltages. It allows use of mixed logic circuitry and provides a voltage bias for N–Channel load control MOSFETs . The third feature is an Enable input that allows a logic level signal to turn–“off” or turn–“on” both switching regulators. Due to the low bias current specifications, these devices are ideally suited for battery powered computer, consumer, and industrial equipment where an extension of useful battery life is desirable. MC34270 MC34271 LIQUID CRYSTAL DISPLAY AND BACKLIGHT INTEGRATED CONTROLLER SEMICONDUCTOR TECHNICAL DATA t 32 1 MC34270 and MC34271 Features: Low Standby Bias Current of 5.0 µA Uncommitted Switching Regulators Allow Both Positive an...