The Human Body Detector is a component that can detect minimal capacitive changes. An efficient way to reduce the power requirements of a device is to turn it off when it is not in use.
This illuminating statement is more important than ever when we consider all the battery driven gadgets that we enjoy today (Smartphones, fitness trackers, In-ear phones, hearing aids, medical wearables and diagnostic equipment).
The MS8890 is a capacitive sensor and switch specifically designed for use in wearables. The MS8890 detects whether an electronic device is being worn or whether it is lying unused on a table. This information can be used to de-energize parts of the electronics and thus save energy - and ultimately increase the battery life and comfort of the electronic device.
The MS8890 is highly configurable and features a very low power consumption (<750nA). The wide voltage range (1.8V to 4.5V) allows direct operation from the battery in most cases. The two sensor channels of the MS8890 can be used to increase the reliability of human body detection or to control two individual sensor functions.
The configuration of the MS8890 is done via an I2C interface. Measuring ranges and switching thresholds of the two sensor channels can be individually programmed. The MS8890 does not need any external components and is easy to integrate into an electronic system. Important parameters can be programmed into a non-volatile memory (e.g., switching thresholds and measuring interval), allowing for autonomous operation.
The capacitive sensor principle of the MS8890 works through a closed housing. This simplifies the housing design compared to other detection principles (e.g., via IR). Eliminating sensor openings in the housing also allow a higher degree of impermeability (for example according to IP67).
Areas of application are: