Hi, expert,
My customer encounters an issue when measure ISO1410 output data, they found the R pin will be pulled down for a short time when use the probe to measure it. Could you please help analysis this issue? Thanks.
Best Regards.
Chen
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Hi, expert,
My customer encounters an issue when measure ISO1410 output data, they found the R pin will be pulled down for a short time when use the probe to measure it. Could you please help analysis this issue? Thanks.
Best Regards.
Chen
Hi Chen,
Thanks for reaching out.
Could you please provide a higher resolution image of the waveform you have shared?
Can you please also request customer to monitor both input (either A-B or A & B separately) and output (R) in one waveform to better compare and share the same with us?
Regards,
Koteshwar Rao
Chen,
Thank you for providing the waveforms as requested!
The provided waveform shows that the output (R) is in the mid-rail, which implies that the output (R) is disabled and in a high impedance state.
Could you please ask the customer to observe the RE bar/DE signal?
Please request the customer to capture the RE bar/DE, A, B, and output (R) in one waveform and share them with us.
Regards,
Chen,
I hope you have resolved your customer's issue by observing the RE bar/DE signal.
Please feel free to reach out to us if you have other questions.
Regards,
Hi, Alfred,
Actually we can see from the test results, every signal goes OK, but they found the software can't read R signal when the probe add to the R pin, should they use special probe to measure R signal or should the add some external circuit to test R signal?
Best Regards.
Chen
Hi Chen,
The R signal drooped because it was disabled. When Output(R) was in high impedance state, no current flowed to the output.
The output(R) could only maintain its state with the amount of charge that has been stored at the output(R).
When the customer probed the output(R) with 1M ohm resistance, the charge/current leaked through the probe.
Hence, the output(R) could not maintain its voltage. In order to ensure a logic high when the output(R) is in
high impedance state, please add a pull-up resistor of 4.7k ohm to the output(R).
Regards,