CAPACITIVE SENSORS AND SWITCHES FOR WEARABLES
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
Feature Overview
| Type | MS8891 | MS8892 | ||
|
Package |
QFN16 (3x3mm) |
Art. 9160407 | QFN16 (3x3mm) |
Art. 9160465 |
| CSP12 (1.03x1.52x0.64mm) |
Art. 9160406 | CSP12 (1.03x1.52x0.64mm) |
Available on request | |
| 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 | Link | ||
| Datasheet | Link | Link | ||
| Application note | Link | Link | ||
| Product flyer | Link | Link | ||
| Arduino example code | Link | Link | ||
| Eval.-Board | Art. 9160388 | Art. 9160464 | ||
Our evaluation boards allow you to easily investigate the different possibilities of using the “Human Body Detector“.
Presentation of the Human Body Detectors function: