General Description

The MAX777L/MAX778L/MAX779L are pulse-skipping DC-DC converters that step up from low-voltage inputs (1V guaranteed). They require only three external components—an inductor(typically 22µH) and two capacitors. The MAX777L delivers a 5V output, the MAX778L generates pin-selectable voltages of 3.0V or 3.3V, and the MAX779L output can be adjusted from 2.5V to 6V through an external resistive divider.

Features

♦ 1V to 4.5V Input Guarantees Start-Up Under Load

♦ Up to 210mA Output

♦ Load Fully Disconnected in Shutdown

♦ 82% Efficiency

♦ Output in Regulation with Input Voltage above Output Voltage

♦ Internal 1A Power Switch and Active Rectifier

♦ Adjustable Current Limit Allows Low-Cost Inductors

♦ 190µA No Load Supply Current

♦ 20µA Shutdown Supply Current

♦ 3V/3.3V (MAX778L), 5V (MAX777L), and Adjustable (MAX779L) Output Voltage

Applications

Single Battery-Cell (1V), Step-Up Voltage Conversion

Efficient, High-Power Step-Up Regulation from

Low Input Voltages

Pagers

Portable Instruments & Hand-Held Terminals

Notebook and Palmtop Computers