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)
  • System wake-up switch (e.g. wearables, IoT, energy harvesting devices)
  • Wrist detection (e.g. wearables or medical wearables)
  • Proximity sensor
  • Proximity switch
  • Touch switch

 

Feature Overview

Type MS8891 MS8892

Package and availability

QFN16
(3x3mm)
Available
(Art. 9160407)
QFN16
(3x3mm)
Samples Q4/20
CSP12
(1.03x1.52x0.64mm)
Available
(Art. 9160406)
CSP12
(1.03x1.52x0.64mm)
Samples Q4/20
Main feature Two sensor channels with high immunity to crosstalk between sensor channels Optimized for system wake-up with absolute or relative switching threshold
Sensor channels 2 1
Meter mode / Switch mode yes / yes yes / yes
Switch threshold absolute absolute or relative
Range / resolution 0 to 400fF / 1.6fF
400 to 800fF / 1.6fF
800 to 1200fF / 1.6fF
1200 to 1600fF / 1.6fF
200 to 1000fF / 3.1fF
Noise filter off / low / high off / low / high
Measuring interval single / 2Hz / 32Hz / permanent single / 2Hz / 8Hz / 32Hz
External clock input x yes
Hardware / software trigger yes / yes yes / yes
Stand-alone operation yes yes
Switch mode outputs 2 1
Selectable output polarity yes yes
Direct / combinational / latching outputs yes / yes / x yes / x / yes
CMOS / open-drain outputs yes / yes yes / yes
Pull-up resistor in open-drain mode x switchable (on/off)
I2C Interface yes yes
I2C sub-address bit x yes
Idle current 50nA 50nA
Average current, external clock
(switch mode, 2 Hz)
x 65nA
Average current, internal clock
(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 Available Q4/20
Datasheet Link Link
Application note Link Available Q4/20
Arduino example code Link Available Q4/20


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

Presentation of the Humen Body Detectors function: