Dual 1A 1.5MHz同步降压转换器--AT7172

一 概述

The AT7172 is a dual high-efficiency Pulse-Width Modulated(PWM) step-down DC-DC converter. It is capable of delivering 1A output current over a wide input voltage range from 2.6V to 5.5V, the AT7172 is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources within the range such as cellular phones, PDAs and other handheld devices.
Two operational modes are available:PWM/Low-Dropout auto-switch and shutdown modes. Internal synchronous rectifier with low RDS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky diode is required in practical application.
The AT7172 enters Low-Dropout mode when normal PWM cannot provide regulated output voltage by continuously turning on the upper PMOS.The AT7172 enter shutdown mode and consumes less than 0.1µA when EN pin is pulled low.
The switching ripple is easily smoothed-out by small
package filtering elements due to a fixed operation
frequency of 1.5MHz.

二 特性

2.6V to 5.5V input voltage range
Output Adjustable from 0.6V to VIN
280/200m? Internal Power MOSFET Switch
Stable with Low ESR Output Ceramic
Capacitors
Up to 95% Efficiency
Less than 1µA Shutdown Current
1.5Mhz Switching Frequency
Thermal Shutdown Protection
Current limit and short circuit protections.
Available in TDFN3x3-10L& TDFN3x3-12L
Pb-Free Package
Build-in soft start function

三 应用

Cellular Telephones
Wireless and DSL Modems
Digital Still Cameras
Mp3 Players
Portable Instruments
Microprocessors and DSP Core Supplies

四 封装

五 应用电路图