• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 31 subscribers
  • Views 284 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

PGA460-Q1: Short Distance Measurement with High Frequency Transducer

PGA460-Q1: There is no envelopment signal after replacing transformer B78416A2386A003

user1327352
Prodigy 35 points
Part Number: PGA460-Q1
Other Parts Discussed in Thread: PGA460, BOOSTXL-PGA460

I also used the transformer B78416A2386A003 to drive the high-frequency probe, but the envelope signals read from PGA460 were all 0 (no signal), and the circuit board's INP pins had signals.This circuit board can drive the low frequency probe to work normally, only the transformer and matching components are changed.Could you please tell me the reason for receiving all zeros?

  • 0
    TI__Mastermind 27950 points

    Hi user1327352,

    Are you using the BOOSTXL-PGA460 EVM GUI to evaluate the high-frequency transducer, or are you using custom software?

    Also, start by removing the matching components in parallel to the transducer to ensure these aren't negatively loading the transducer.

    If using custom software, remember that you must manually update the PGA460' band-pass filter coefficient register values when using the high-frequency mode. The GUI automatically performs this register write operation in the background. The BOOSTXL-PGA460 EVM GUI includes a look-up table of the coefficient values based on the transducer's frequency.

    See PGA460 FAQ # 5.10 "How do I successfully use a high-frequency transducer (180-480kHz) with the GUI?" for more details: http://www.ti.com/lit/an/slaa733/slaa733.pdf

    The fact that your envelope signal reads all '0's indicates there may be a different issue though. Are you writing to the threshold register space to clear the THR_CRC_ERR? If THR_CRC_ERR=1, then the device will not update the echo data dump values.