Driver Powers Active-Matrix TFT LCDs

In the MAX1664 IC, designers find the power supply and backplane drive circuitry for active-matrix TFT LCDs. Included are: a single-output, PWM boost converter with a 0.25 ohm switch; a dual-output, single-inductor converter with complementary switches; an LCD backplane driver with complementary 0.35 ohm switches; and a simple PLL that miminizes interference by synchronizing the three outputs.The device's phase-locked operation and 1-MHz nominal switching frequency maintain low output noise while enabling use of tiny external components. Input range of 2.8V to 5.5V allows use with any logic supply. Output voltages are adjustable and a logic-level shutdown is included.