Sensor for on-head detection

[StPr_4549631]

Hello,

I'm currently searching for a capacitive sensor IC to detect if a Bluetooth headset is being worn by the user. Can this work with one sensor pad (self-capacitance sensing) or would that be a proximity sensing application?

Furthermore, the IC should be able to handle a touch slider (three electrodes) at the same time as detecting if the headset is being worn.

As far as I understand this combined application would require two touch FPCs: one towards the users head for the on-head sensing and a second FPC on the outside of the headset for the touch slider operation. Is this the case?

Could you please advice a suitable device for this application?

Thank you!

[Hari · Accepted solution]

Hi @StPr_4549631 

The user wear detection is a typical proximity sensing application. This is because we do not expect the user's ears to be touching the sensor, but instead to be placed at a distance from the sensor. We would recommend having a loop sensor for this application. 

It is possible to have the slider as well detecting along with the proximity sensor from the same IC. This would require additional GPIOs but we can have sliders and proximity sensor running together. 

This will require two different FPCs. I would assume the proximity sensor to be placed on the inside of the headphone and the sliders to be present on the outer covering. This would require two different FPCs connecting to the same IC. 

I would recommend the 4000S device as this has the latest CapSense IP while being cost and size optimized. 

Best regards, 
Hari