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TDC1000-Q1: Receiver filter design

Mike Jung
Intellectual 700 points
Part Number: TDC1000-Q1
Other Parts Discussed in Thread: TDC1000-C2000EVM, TDC1000

Dear TI member.

My customer is testing using the 1MHz transducer.

In datasheet figure 19,

It is recommended due to noise and timing accuracy.

I think high-pass corner frequency and low pass corner frequency is the available frequency band.

but after passing the Rf1 resistance, the attenuation is high.

if it doesn't matter, they want to remove the filter.

or if we need to design a filter, how should we determine fc(center freq.) and fb(filter bandwidth) ?

Thanks.

  • 0
    TI__Mastermind 31655 points

    Hi Mike,

    If this is being used with the TDC1000-TDC7200EVM or TDC1000-C2000EVM, the filter is already designed with a 1Mhz transducer in mind. I would not recommend removing the filter entirely, as this would increase the noise more than it decreases the attenuation of the signal, so the signal to noise ratio will just get worse and make measurements unreliable.

    If you would like to design your own filter there are instructions for a simple one in the TDC1000 datasheet ()  in the receiver filter section 8.3.5.

    Additionally, I have created a bandpass filter centered at 1Mhz in TINA that should have slightly less attenuation than the one on the EVM: 0268.1MhzFilter.TSC

    Regards,

  • 0 in reply to Scott Cummins
    Intellectual 700 points
    Thank you for your response

    with reference to datasheet figure 19,
    We tested to zero ohms to reduce the attenuation.
    and when both Cf2 and Rf2 are removed, the signal attenuation and performance are unaffected.

    if only the CF3 is applied with the bandpass filter, can it be problem?

    Thanks.