参数资料
型号: MPR031EPR2
厂商: Freescale Semiconductor
文件页数: 8/33页
文件大小: 0K
描述: IC CTLR TOUCH SENSOR 8-DFN
产品培训模块: MPR03x - Low-Power Proximity Sensors
特色产品: MPR03x Proximity Capacitive Touch Sensor Controllers
标准包装: 1
类型: 电容性
触摸面板接口: 2 线
评估套件: 可供
数据接口: I²C,串行
数据速率/采样率 (SPS,BPS): 400k
电源电压: 1.71 V ~ 2.75 V
电流 - 电源: 43µA
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 8-UFDFN
供应商设备封装: 8-QFN-D(2x2)
包装: 标准包装
产品目录页面: 2808 (CN2011-ZH PDF)
配用: KITMPR03XEVM-ND - KIT EVAL FOR MPR03X
DEMOMPR031-ND - BOARD DEMO FOR MPR031 CTLR
其它名称: MPR031EPR2DKR
MPR03X
Sensors
16
Freescale Semiconductor
7
Theory of Operation
7.1
Introduction
The MPR03X utilizes the principle that a capacitor holds a fixed amount of charge at a specific electric potential. Both the
implementation and the configuration will be described in this section.
7.2
Capacitance Measurement
The basic measurement technique used by the MPR03X is to charge up the capacitor C on one electrode input with a DC current
I for a time T (the charge time). Before measurement, the electrode input is grounded, so the electrode voltage starts from 0 V
and charges up with a slope, Equation 1, where C is the pad capacitance on the electrode (Figure 21). All of the other electrodes
are grounded during this measurement. At the end of time T, the electrode voltage is measured with a 10 bit ADC. The voltage
is inversely proportional to capacitance according to Equation 2
.The electrode is then discharged back to ground at the same
rate it was charged.
Equation 1
Equation 2
Figure 21. MPR03X Electrode Measurement Charging Pad Capacitance
When measuring capacitance there are some inherent restrictions due to the methodology used. On the MPR03X the voltage
after charging must be in the range that is shown in Figure 22.
Figure 22.
C
I
dt
dV
C
T
I
V
Electrode Charge Time
T
V
Electrode
Voltage
Electrode
Charging
Electrode
Discharging
Electrode voltage measured here
2T
Electrode Discharge Time
Valid ADC Values vs. VDD
0
100
200
300
400
500
600
700
800
900
1.71
1.91
2.11
2.31
2.51
2.71
VDD (V)
ADC
Counts
ADChigh
ADCmid
ADClow
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相关代理商/技术参数
参数描述
MPR031EPR2 制造商:Freescale Semiconductor 功能描述:IC CAPACITIVE TOUCH SENSOR FN-8
MPR031EPR2-CUT TAPE 制造商:Freescale 功能描述:MPR031 Series 2.75 V 8 ? Proximity Capacitive Touch Sensor Controller - UDFN-8
MPR032 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Proximity Capacitive Touch Sensor Controller
MPR032EP 制造商:Freescale Semiconductor 功能描述:CAPACITIVE TOUCH SENSOR 8-PIN UDFN BULK - Bulk
MPR032EPR2 功能描述:电容触摸传感器 DFN TOUCH PAD RoHS:否 制造商:Microchip Technology 电源电压: 通道数量: 封装 / 箱体: 尺寸: 温度范围: