MAX20070B

MAX20070/MAX20070B EVALUATION KIT AVAILABLE Integrated TFT Power Supplies and LED Backlight Drivers General Description The MAX20070/MAX20070B are highly integrated power supplies and LED backlight drivers for automotive TFT-LCD applications. The devices integrate one buckboost converter, one boost converter, two gate-driver supplies, and a boost/SEPIC converter that can power one to two strings of LEDs in the display backlight. The source-driver power supplies consist of a boost converter and an inverting buck-boost converter that can generate voltages up to +15V and -15V. Both sourcedriver power supplies can deliver up to 100mA. The positive source-driver supply regulation voltage (VPOS) is set by connecting an external resistor-divider on FBP. Connecting the FBP pin to ground sets the regulation voltage (VPOS) to +6.5V. The negative source-driver supply voltage (VNEG) is always tightly regulated to -VPOS within +50mV. The source-driver supplies use an input voltage from 2.7V to 5.5V to generate the output voltages. The gate-driver power supplies consist of regulated charge pumps that generate up to +22V and -22V and can deliver up to 3mA each. The regulation voltage (VGVDD) on the positive charge pump is set by a resistor-divider on FBPG; the regulation voltage (VGVEE) on the negative charge pump is set by a resistor-divider on FBNG. The ICs feature a dual-string LED driver that operates off a separate input voltage (VBATT) and can power up to two strings of LEDs with 16...