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TDC1000-C2000EVM: Use the TDC1000-C2000EVM evaluation board to drive the 76kHz ultrasonic transducer

tery shi
Prodigy 30 points
Part Number: TDC1000-C2000EVM
Other Parts Discussed in Thread: PGA460, TDC1000, MSP430FR6043

If you want to drive a 76kHz ultrasonic transducer with the TDC1000-C2000EVM evaluation board, do you need to modify the hardware circuitry?  How the GUI configures registers.  I want to use a 5MHz signal at 64 frequencies. 

  • +1
    TI__Mastermind 23045 points

    Hello Tery,

    Thanks for posting to the sensing forum! The TDC1000-C2000EVM is capable of handling a 76kHz transducer but we do not typically suggest operation of under 1MHz transducers on this device. We instead we typically suggest using PGA460, or TUSS44x0.

    To answer you other question the device would EVM would require modification, there are inter-stage filters that are currently setup for 1MHz operation and clock modification  would also be required. The device uses the input clock to produce the TX signal, but the clock can only be divided by powers of 2, so you would need to modify the input clock to a frequency that could be easily divided by a power of 2 to equal 76kHz.

    I am not sure what you mean by 5MHz at 64 frequencies, do you mean use a 5MHz clock divided by 64?

    Looking forward to your response!

    Best,

    Isaac

  • 0 in reply to Isaac Lara
    Prodigy 30 points

    Thank you very much! Crystal oscillator at 5 MHZ 64 frequency division gives me 78kHz, and here's how I did it. But when I put the sensor in a different position during the test, the measured time did not change. In general, the time should vary as the sensor position changes. I'm testing distance.

  • 0 in reply to Isaac Lara
    Prodigy 30 points

    I want to use two ultrasonic transducers to detect airflow velocity, can TDC1000 be used in this scene? I have read in the forums that it is not recommended to use TDC1000 in this way.

  • 0 in reply to tery shi
    TI__Mastermind 23045 points

    Hello Tery,

    Thanks for clarifying, yes that should get you close to the transducers resonant frequency just keep in mind this might not be the ideal for some transducers.

    The main reason why the device could be triggering at the same point is due to the listening window on the TDC1000 is not set up correctly. If the listening window is not set up appropriately the device could be triggering a STOP on the transducers output. You can usually confirm this if the ToF is very low. Please refer to section 8.4.6.2 Standard TOF Measurement of the TDC1000 datasheet for more info on how to configure the listening window.

    As far as flow measurements TDC1000 is not the recommended device for this application, the MSP430FR6043 is the recommended solution for flow applications: https://www.ti.com/product/MSP430FR6043

    The TDC1000 is capable of doing flow but has a lower accuracy compared to the MSP430 solution, and another thing to note is that the frequency at which you are looking at is not recommended for use with the TDC1000. The TDC1000 excites the transducer with a small voltage for air applications.

    Feel free to let me know if you have any other questions!

    Best,

    Isaac