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Human Body Detector

The MS889X-series are capacitive sensors and switches that have been specifically developed for use in “Wearables“. When the MS889X functions as a switch, an external sensor capacitance is compared to a programmed threshold to detect whether the external value lies above or below the threshold. The MS889X-series have an ultra-low current consumption (750nA) between 1.8V and 4.5V and is ideal for use in battery operated systems. There are numerous programming options to aid simple integration into an electronic system. Important parameters can be programmed into a non-volatile memory to allow autonomous operation.

 

Applications

  • Human Body Detection (e.g. “In-ear phones“ or finger detector)
  • Wrist detection (e.g. wearables or medical wearables)
  • Fluid detection (e.g. coffee machine)
  • Proximity sensor
  • Proximity switch
  • Touch switch

 

Feature Overview

Type MS8890 MS8891

Package and availability

QFN16
(3x3mm)
Available
(Art. 9160384)
QFN16
(3x3mm)
Samples on request
(Art. 9160386)
CSP12
(1.03x1.52x0.64mm)
Available Q4/2018
(Art. 9160385)
CSP12
(1.03x1.52x0.64mm)
Available on request
Main feature Low sensor pin count for 2 channel operation High immunity to crosstalk between sensor channels
Sensor channels 2 2
Sensor inputs / outputs 2 / 1 2 / 2
Meter mode yes yes
Switch mode yes yes
One / two channel operation yes / yes yes / yes

Range / resolution

0 to 50fF / 0.2fF 0 to 400fF / 1.6fF
50 to 100fF / 0.4fF 400 to 800fF / 1.6fF
100 to 200fF / 0.8fF 800 to 1200fF / 1.6fF
200 to 400fF / 1.6fF 1200 to 1600fF / 1.6fF
8/9 bit resolution yes x
Threshold per channel yes yes
RAM/ROM mode yes yes
Noise filter: off / low / high yes / yes / yes yes / yes / yes
Measuring interval:
single / 2 Hz / 32 Hz / permanent
yes / yes / yes / yes yes / yes / yes / yes
Hardware / software trigger yes yes
Stand-alone operation yes yes
Switch mode outputs 2 2
Output polarity selectable yes yes
Direct / combinational outputs yes / x yes / yes
CMOS / open-drain outputs yes / x yes / yes
I2C Interface yes yes
Interrupt over I2C yes yes
Idle current 50nA 50nA
Average current
(switch mode, 2 Hz)
725nA 725nA
Voltage range 1.8 to 4.5V 1.8 to 4.5V
Temperature range -40 to +85°C -40 to +85°C
Summary Link Link
Datasheet Link Link
Application note Link Link
Arduino Beispiel-Code Link Link

Our evaluation boards allow you to easily investigate the different possibilities of using the “Human Body Detector“.