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FDC2214PROXSEN-EVM: Solution for outdoor proximity sensing

Part Number: FDC2214PROXSEN-EVM
Other Parts Discussed in Thread: FDC2214, FDC1004, PGA460

Hello,

I'm evaluating the FDC2214 for a proximity sensor in an outdoor setting. between single-end, differential, shield, no-shield, what is the best solution for outdoors?

Besides the weather, I have to consider EMI, mounting to metal that may or may not be earth-grounded.

Also, how does the FDC1004 compare?

  • Thank you for your interest in TIs product for proximity sensing. 

    For proximity sensor for outdoor application it really depends on the application, distance, object  and accuracy you are expecting. The decision to choose FDC2214 vs FDC1004 relies on the sensor design. The FDC1004 maximum sensor is 15pF where as the FDC2214 can operate up to nF of capacitance. The FDC1004 does have active shielding which helps in eliminating parasitics that can help improve accuracy.  

    The FDC2214 architecture is based on the resonant drive which essentially is driving the inductance and capacitive sensor at resonance. In regards to EMI its very subjective and application dependent. Once you have identified the sensor design and have built a prototype using our devices EMI and EMC testing needs to be performed and upon results there may be that the sensor design needs to be tweaked to pass EMI. 

    We typically see FDC solution being used for liquid level sensing and for proximity sensing or object detection Ultrasonic solution is preferred. Here is the information on object detection using PGA460 our Ultrasonic solution http://www.ti.com/tool/PGA460PSM-EVM 

  • Hello Arjun,

    Thank you for your reply.

    I failed to mention that the application is detecting a hand wave at around 6 inches away, outdoors.

    I looked at the Ultrasonic solutions and I'm not sure if one sensor can sense at that distance while being behind a plastic enclosure.

    Saad

  • Hi Saad,

    Thanks for the additional information. If you like to proceed with the FDC devices you can certainly order the EVM and evaluate based on your environment. We do have an app note here that talks about proximity sensing using FDC devices https://www.ti.com/lit/an/snoa940a/snoa940a.pdf?&ts=1589841552476 The sensor needs to be designed such that the hand gesture is recognized behind the plastic casing. 

    In regards to using ultrasonic, if you can use one of the closed top ultrasonic transducers you would need to have a cut out in the plastic and be able to send and receive tones. Just like how its implemented on the car bumpers for park assist applications.