General Description

The MAX1970/MAX1971/MAX1972 dual-output current-mode PWM buck regulators operate from 2.6V to 5.5V input and deliver a minimum of 750mA on each output. The MAX1970 and MAX1972 operate at a fixed 1.4MHz (MAX1971 operates at 700kHz) to reduce output inductor and capacitor size and cost. Switching the regulators 180° out-of-phase also reduces the input capacitor size and cost. Ceramic capacitors can be used for input and output.

Features

♦ Current-Mode, 1.4MHz Fixed-Frequency PWM Operation

♦ 180° Out-of-Phase Operation Reduces Input Capacitor

♦ ±1 Output Accuracy Over Load, Line, and Temperature Ranges

♦ 750mA Guaranteed Output Current

♦ 2.6V to 5.5V Input

♦ Power-On Reset Delay of 16.6ms (MAX1970) or 175ms (MAX1971 and MAX1972)

♦ Power-Fail Output (MAX1970 and MAX1972 Only)

♦ Power-On Reset Input (MAX1971 Only)

♦ Operation Outside xDSL Band

♦ Ultra-Compact Design with Smallest External Components

♦ Outputs Adjustable from 0.8V to VIN or 1.8V/3.3V and 1.5V/2.5V Preset

♦ All-Ceramic Capacitor Application

♦ Soft-Start Reduces Inrush Current

Applications

xDSL Modems

xDSL Routers

Copper Gigabit SFP and GBIC Modules

USB-Powered Devices

Dual LDO Replacement