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高效率、PWM、降压型控制器(外部P沟道驱动器)

产品详情

主要特征

应用/用途

简化框图

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主要特征

  • 90% to 95% Efficiency for 50mA to 2.5A Output Currents
  • 4V to 15V Input Voltage Range
  • Low 800µA Supply Current
  • 0.6µA Shutdown Current
  • Drives External P-Channel FETs
  • Cycle-by-Cycle Current Limiting
  • 2V ±1.5% Accurate Reference Output
  • Adjustable Soft-Start
  • Precision Comparator for Power-Fail or Low-Battery Warning

应用/用途

  • 5V至3.3V绿色PC应用
  • 电池供电应用
  • 蜂窝电话
  • 笔记本电脑电源
  • PDA及其它手持设备

描述

The MAX747 high-efficiency, high-current, step-down controller drives external P-channel FETs. It provides 90% to 95% efficiency from a 6V supply with load currents ranging from 50mA up to 2.5A. It uses a pulse-width-modulating (PWM) current-mode control scheme to provide precise output regulation and low output noise. The MAX747's 4V to 15V input voltage range, a fixed 5V/adjustable (Dual-Mode™) output, and a current limit set with an external resistor make this device ideal for a wide range of applications.

High efficiency is maintained with light loads due to a proprietary dual-control (Idle-Mode™) scheme that minimizes switching losses by reducing the switching frequency at light loads. The low 800µA quiescent current and ultra-low 0.6µA shutdown current further extend battery life.

External components are protected by the MAX747's cycle-by-cycle current limit. The MAX747 also features a 2V ±1.5% reference, a comparator for low-battery detection or level translating, as well as soft-start and shutdown capability.

The MAX746, discussed in a separate data sheet, functions similarly to the MAX747, but it drives N-channel logic level FETs on the high side.

简化框图

MAX747:典型工作电路 MAX747:典型工作电路 Zoom icon

支持和培训

在Maxim的知识库中搜索技术问题的答案

过滤搜索

Maxim的专业工程师团队也会为您解答相应的技术问题,请访问Maxim的 支持中心