Microchip MCP4017数字电位器应用方案
作者: 时间:2009-05-24 13:36 来源:
Microchip 公司的MCP4017/18/19是通用的数字电位器,具有7位电阻网络分辨率,有127个电阻,具有低的温度系数:绝对值(0-70℃)为50ppm,比值为10ppm,工作电压1.8V到5.5V. MCP4017/18/19可应用在设定电或失调调整,传感器校准,替代机械式电位计和可选择增益和失调放大器设计.本文介绍了MCP4017/18/19的主要特性, 方框图, 和微控制器(MCU) 典型连接框图, 采用MCP4017调整非反相放大器失调和增益方框图以及采用MCP4018的可编滤波器和采用MCP4017的惠斯通电桥调整框图。
The MCP4017/18/19 devices are general purpose digital potentiometers intended to be used in applications where a programmable resistance with moderate bandwidth is desired.
This Data Sheet covers a family of three Digital Potentiometer and Rheostat devices. The MCP4018 device is the Potentiometer configuration, while the MCP4017 and MCP4019 devices are the Rheostat configuration.
MCP4017/18/19主要特性:
Potentiometer or Rheostat configuration options
7-bit: Resistor Network Resolution
127 Resistors (128 Steps)
Zero Scale to Full Scale Wiper operation
RAB Resistances: 5 kΩ, 10 kΩ, 50 kΩ, or 100 kΩ
Low Wiper Resistance: 100Ω (typical)
Low Tempco:
Absolute (Rheostat): 50 ppm typical (0℃ to 70℃)
Ratiometric (Potentiometer): 10 ppm typical
Simple I2C Protocol with read & write commands
Brown-out reset protection (1.5V typical)
Power-on Default Wiper Setting (Mid-scale)
Low-Power Operation:
2.5 μA Static Current (typical)
Wide Operating Voltage Range:
2.7V to 5.5V - Device Characteristics Specified
1.8V to 5.5V - Device Operation
MCP4017/18/19应用:
Applications generally suited for the MCP401X devices include:
Set point or offset trimming
Sensor calibration
Selectable gain and offset amplifier designs
Cost-sensitive mechanical trim pot replacement
图1.MCP4017/18/19方框图

图2.MCP4017/18/19和微控制器(MCU)典型连接框图

图3.MCP4017/18/19设定电或阈值校准

图4.采用MCP4017调整非反相放大器失调和增益方框图

图5.采用MCP4018的可编滤波器

图6.采用MCP4017的惠斯通电桥调整框图