General Description

The MAX1729 micropower step-up/step-down DC-DC converter is ideally suited for electrically controlled birefringence (ECB) and liquid-crystal-display (LCD) bias supply generation. It provides step-up/step-down voltage conversion and reduces output ripple by using a step-up DC-DC converter followed by a linear regulator. This architecture permits a physically smaller inductor than those used in competing SEPIC and flyback topologies. This device features low quiescent current(67µA typical). A logic-controlled shutdown mode further reduces quiescent current to 0.4µA typical.

Features

♦ High-Accuracy Reference Voltage (±1)

♦ ±11ppm/°C Output Voltage Drift

♦ On-Chip Temperature Sensor Output

♦ Accurate Voltage and Temperature Provide:

Consistent ECB Colors

Consistent LCD Gray-Scale Contrast

♦ +2.7V to +5.5V Input Voltage Range

♦ Output Voltage Range

+2.5V to +16V in Internal Feedback Mode

Programmable in External Feedback Mode

♦ Dynamic Control of the Output Voltage

♦ 67µA Supply Current

♦ 0.4µA Shutdown Current

♦ 10-Pin µMAX Package (1.09mm max height)

♦ Evaluation Kit Available (MAX1729EVKIT)