MAX686:DAC控制、boost反相型LCD偏置电源,内置开关

The MAX686 DAC-controlled boost/inverter IC converts a positive input voltage to a positive or negative LCD bias voltage up to +27.5V or -27.5V. The device features an internal N-channel MOSFET switch, programmable current limiting, and an internal 6-bit digital-to-analog converter (DAC) for digital adjustment of the output voltage. It comes in a small 16-pin QSOP package (same size as an 8-pin SO). The MAX686 uses a current-limited, pulse-frequency-modulation (PFM) control scheme to provide high efficiency over a wide range of load conditions. Its high switching frequency (up to 300kHz) allows the use of small external components. An LCDON output allows the LCD bias voltage to be automatically disabled when the display logic voltage is removed, protecting the display. The MAX686 has a +2.7V to +5.5V input voltage range for the IC, and a +0.8V to +27.5V input voltage range for the inductor. Typical quiescent supply current is 65µA. Shutdown current is 1.5µA. The MAX686 offers high-level integration to save space, reduce power consumption, and increase battery life, making it an excellent choice for battery-powered portable equipment. The MAX629 is similar to the MAX686, except that it does not contain a built-in DAC. Both devices have evaluation kits to facilitate designs.

关键特性
  • Internal 500mA, 28V N-Channel Switch (no external FET required)
  • Adjustable Output Voltage to +27.5V or -27.5V
  • 6-Bit DAC-Controlled Output Voltage
  • Up to 90% Efficiency
  • Small 16-Pin QSOP Package (Same size as 8-pin SO)
  • Power-OK Indicator
  • 65µA Quiescent Current
  • 1.5µA Shutdown Current
  • Up to 300kHz Switching Frequency
功能框图
MAX686:典型工作电路
产品应用
  • 笔记本电脑
  • 掌上电脑
  • PDA及其它手持设备
  • 便携式数据收集终端
  • LCD正或负偏置
  • 变容调谐二极管偏置
关键参数
Part NumberVIN
(V)
VIN
(V)
IOUT1
(A)
Output Adjust. MethodDC-DC OutputsAlternate TopologyOper. Freq.
(kHz)
Switch TypePackage/PinsBudgetary
Price
minmaxmaxSee Notes
Part NumberVIN
(V)
VIN
(V)
IOUT1
(A)
Output Adjust. MethodSwitch TypeDC-DC OutputsOper. Freq.
(kHz)
Package/PinsBudgetary
Price
minmaxmaxSee Notes
MAX6862.75.50.1
Digital
Resistor
1
Inverting
Step-Up
300Internal
QSOP/16
$3.72 @1k
MAX6862.75.50.1
Digital
Resistor
Internal1300
QSOP/16
$3.72 @1k
数据手册DataSheet
英文MAX686.pdfRev 1; 02/1998
开发工具
质量和环境数据
订购型号
型号状况推荐替代产品封装温度RoHS/无铅
MAX686C/D停止供货DICE SALES,;NA引脚;DICE;参考数据资料
MAX686EEE停止供货MAX686EEE+QSOP,;16引脚;30.9mm²-40°C至+85°CRoHS/无铅:否
MAX686EEE+生产中QSOP,;16引脚;30.9mm²-40°C至+85°CRoHS/无铅:无铅
MAX686EEE+T生产中QSOP,;16引脚;30.9mm²-40°C至+85°CRoHS/无铅:无铅
MAX686EEE-T停止供货MAX686EEE+TQSOP;16引脚-40°C至+85°C参考数据资料
MAX686.pdf MAX686
MAX686.pdf MAX686
MAX686.pdf MAX686
MAX686.pdf MAX686
MAX686.pdf MAX686