MAX1774:双路、高效率、降压型转换器,带有备用电池切换开关

双输出降压型DC-DC转换器,用于PDA/掌上电脑,提供自动电池切换

The MAX1774 is a complete power-supply solution for PDAs and other hand-held devices. It integrates two high-efficiency step-down converters, a boost converter for backup battery regulation, and four voltage detectors in a small 32-pin QFN or 28-pin QSOP package. The MAX1774 accepts inputs from +2.7V to +28V and provides an adjustable main output from 1.25V to 5.5V atover 2A. The secondary core converter delivers an adjustable voltage from 1V to 5V and can deliver up to 1.5A. Both the main and core regulators have separate shutdown inputs. When the AC adapter power is removed, an external P-channel MOSFET switches input to the main battery. When the main battery is low, the backup step-up converter sustains the main output voltage. When the backup battery can no longer deliver the required load, the system shuts down safely to prevent damage. Four on-board voltage detectors monitor the status of the AC adapter power, main battery, and backup battery. The MAX1774 evaluation kit is available to help reduce design time.

关键特性
  • Dual, High-Efficiency, Synchronous-Rectified Step-Down Converters
  • Thin, Small (1mm High) QFN Package
  • Step-Up Converter for Backup Battery
  • Main Power
    • Adjustable from +1.25V to +5.5V
    • Over 2A Load Current
    • Up to 95% Efficiency
  • Core Power
    • Adjustable from 1V to 5V
    • Internal Switches
    • Up to 1.5A Load Current
    • Up to 91% Efficiency
  • Automatic Main Battery Switchover
  • 100% (max) Duty Cycle
  • Up to 1.25MHz Switching Frequency
  • Input Voltage Range from +2.7V to +28V
  • Four Low-Voltage Detectors
  • 170µA Quiescent Current
  • 8µA Shutdown Current
  • Digital Soft-Start
  • Independent Shutdown Inputs
MAX1774:功能框图
MAX1774:功能框图
应用
  • 手持式计算机
  • 网络浏览器
  • PDA
  • POS终端
  • 亚笔记本电脑
数据手册DataSheet
语言下载文件备注
英文MAX1774.pdfRev 2; 02/2004
关键参数
Part NumberPrimary TopologyMonitor/Control FeaturesDC-DC/Power FeaturesBattery Charger FeaturesVIN
(V)
VIN
(V)
VOUT
(V)
VOUT
(V)
Max. IOUT
(A)
Max. IOUT
(A)
Oper. Freq.
(kHz)
Package/PinsBudgetary
Price
minmaxminmaxSee Notes
MAX1774Step-DownShutdown
  • Current Limit
  • Fixed Freq./PWM
  • Soft Start
  • Sync. Rectifier
Battery Backup2.72815.522600QSOP/28$4.03 @1k
开发工具
技术资料
相关产品
  • MAX1775:双输出、降压型DC-DC转换器,用于PDA/掌上电脑
订购型号
型号状况推荐替代产品封装温度RoHS/无铅
MAX1774EEI停止供货MAX1774EEI+QSOP,;28引脚;61.9mm²-40°C至+85°CRoHS/无铅:否
MAX1774EEI+生产中QSOP,;28引脚;61.9mm²-40°C至+85°CRoHS/无铅:无铅
MAX1774EEI+T生产中QSOP,;28引脚;61.9mm²-40°C至+85°CRoHS/无铅:无铅
MAX1774EEI-T停止供货MAX1774EEI+TQSOP;28引脚-40°C至+85°C参考数据资料
MAX1774EMJ停止供货MAX1774EEI+-40°C至+85°C参考数据资料
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功能框图 MAX1774