MAX1688:升压型DC-DC转换器,提供精密的自适应限流,用于GSM

能够使GSM电池的峰值电流降低6倍,可消除发射过程中的DC-DC电源噪声,用户可选择禁止

The MAX1687/MAX1688 step-up DC-DC converters deliver up to 2W from a single Li-Ion or three NiMH cells. The devices are ideal for burst-load applications such as GSM cell phones and wireless LANs, where the RF power amplifiers require short, high current bursts. The MAX1687/MAX1688 reduce battery surge current by slowly charging a reservoir capacitor, which supplies the necessary peak energy for the load current burst. As a result, the peak battery current is limited, thus maximizing battery life and minimizing battery voltage sag and transient dips. An internal synchronous rectifier provides over 90% conversion efficiency and eliminates the need for an external Schottky diode. A logic shutdown mode reduces the shutdown current to only 3µA. The devices can be disabled during current bursts (RF transmit mode) to eliminate switching noise. The switching frequency of the MAX1687/MAX1688, controlled by the selected inductor, can exceed 1MHz. Two external resistors set the output voltage from 1.25V to 6V. The MAX1687 controls peak battery current, while the MAX1688 features a more advanced, adaptive constant-recharge-time algorithm that maximizes battery life. The MAX1687/MAX1688 are available in thin 16-pin TSSOP (1.1mm max height) or standard 8-pin SO packages.

关键特性
  • Low 450mA Peak Battery Current Provides 2A, 5V GSM Burst
  • 90% Efficiency
  • Internal Power MOSFETs and Current-Sense Resistor
  • Output Disconnects from Input During Shutdown
  • 3µA Shutdown Current
  • Precise Voltage-Controlled Current Limit (MAX1687)
  • Adaptive Constant-Recharge-Time Capability (MAX1688)
  • 1.25V to 6V Adjustable Output
  • 2.7V to 6V Input Range (1 Li-Ion cell or 3 NiMH cells)
  • Switching Frequency Can Exceed 1MHz
  • Standby Mode Disables DC-DC During Transmission Burst
  • Low Inrush Current at Start-Up
MAX1687、MAX1688:典型工作电路
MAX1687、MAX1688:典型工作电路
应用
  • GSM电话
  • PC卡(PCMCIA)
  • 无线手机
数据手册DataSheet
语言下载文件备注
英文MAX1687-MAX1688.pdfRev 0; 02/1999
关键参数
Part NumberVIN
(V)
VIN
(V)
VOUT1
(V)
VOUT1
(V)
IOUT1
(A)
Output Adjust. MethodSwitch TypeSynchronous SwitchingICC
(mA)
Shutdown Mode Supply Current
(µA)
DC-DC OutputsOper. Freq.
(kHz)
Package/PinsBudgetary
Price
minmaxminmaxmaxtyptypSee Notes
MAX16872.761.2562.5ResistorInternalYes231500
  • SOIC(N)/8
  • TSSOP/16
$2.48 @1k
MAX1688
  • SOIC(N)/8
  • TSSOP/16
开发工具
订购型号
型号状况推荐替代产品封装温度RoHS/无铅
MAX1688ESA停止供货MAX1688ESA+SOIC(N),;8引脚;30.9mm²-40°C至+85°CRoHS/无铅:否
MAX1688ESA+生产中SOIC(N),;8引脚;30.9mm²-40°C至+85°CRoHS/无铅:无铅
MAX1688ESA+T生产中SOIC(N),;8引脚;30.9mm²-40°C至+85°CRoHS/无铅:无铅
MAX1688ESA-T停止供货MAX1688ESA+TN.SO;8引脚-40°C至+85°C参考数据资料
MAX1688EUE停止供货MAX1688EUE+TSSOP,;16引脚;33.4mm²-40°C至+85°CRoHS/无铅:否
MAX1688EUE+生产中TSSOP,;16引脚;33.4mm²-40°C至+85°CRoHS/无铅:无铅
MAX1688EUE+T生产中TSSOP,;16引脚;33.4mm²-40°C至+85°CRoHS/无铅:无铅
MAX1688EUE-T停止供货MAX1688EUE+TTSSOP,;16引脚;33.4mm²-40°C至+85°CRoHS/无铅:否
MAX1687-MAX1688.pdf MAX1688
典型工作电路 MAX1688