MAX8798 Datasheet | Maxim Integrated

19-0971; Rev 0; 9/07 Internal-Switch Boost Regulator with Integrated 3-Channel Scan Driver for TFT LCDs General Description The MAX8798 includes a high-performance, step-up regulator; a high-speed operational amplifier; a digitally adjustable V calibration device with nonvolatile memory and an I2C interface; and a high-voltage, levelshifting scan driver. The device is optimized for thin-film transistor (TFT) liquid-crystal display (LCD) applications. The step-up DC-DC converter provides the regulated supply voltage for panel source driver ICs. The high switching frequency allows the use of ultra-small inductors and ceramic capacitors. The current-mode control architecture provides fast transient response to pulsed loads typical of source driver loads. The step-up regulator Features soft-start and current limit. The high-current operational amplifier is designed to drive the LCD backplane (V). The amplifier Features high output current (±150m A), fast slew rate (45V/µs), wide bandwidth (20MHz), and rail-to-rail inputs and outputs. The programmable V calibrator is externally attached to the V amplifier’s resistive voltage-divider and sinks a programmable current to adjust the V output-voltage level. An internal 7-bit digital-to-analog converter (DAC) controls the sink current. The DAC is ratiometric relative to BOOST and is guaranteed to be monotonic over all operating conditions. The calibrator IC includes an EEPROM to store the desired V voltage level. The 2-wire I2C interface between the LCD panel and the programming circuit minimizes panel connector pin count and simplifies production equipment. .. The high-voltage, level-shifting scan driver is designed to drive the TFT panel gate drivers. Its three outputs swing from +35V (maximum) to -25V (minimum) and can swiftly drive capacitive loads. To save power, the two plementary outputs are designed to allow charge sharing during state changes. The MAX8798 is available in a...