AFE7225EVM: Lower cut off frequency

Yudhi K

Part Number: AFE7225EVM
Other Parts Discussed in Thread: AFE7225

Hi,

Can you please tell me what is the lower cut-off frequency for both ADC input and DAC output of AFE7225EVM? (since they are transformer coupled, I expect that there will be a lower frequency cut-off and I couldn't find a value for it mentioned anywhere). Also couldn't find a data sheet for the AFE7225EVM (I downloaded the user guide and schematic), it would be helpful if you could guide me to its data sheet.

Thanks,

Yudhi

over 5 years ago

0 Jim Brinkhurst1 over 5 years ago

TI__Mastermind 43860 points

Hi Yudhi
We have received your question. The AFE7225 expert will provide a more detailed response soon.
Best regards,
Jim B

0 Yusuf%20Agoro over 5 years ago

TI__Expert 4880 points

Hey Yudhi,

The lower cutoff frequencies is 400kHz for the RX and 4MHz for the TX. Both are set by the ADT1-1WT & ADT4-1WT input transformers.

Here is the link for the datasheet.
www.ti.com/.../afe7225.pdf

Thanks

Yusuf

0 Yudhi K over 5 years ago in reply to Yusuf%20Agoro

Prodigy 20 points

Hi Yusuf,

Thanks for your reply. Can I bypass the transformer using R47, R49 and R57 for lower TX frequency (upto 40kHz)?

Thanks,

Yudhi

0 Yusuf%20Agoro over 5 years ago in reply to Yudhi K

TI__Expert 4880 points

Yudhi,

Technically you could but this is not necessarily recommended. Ideally the transformer is used to match impedance for max power transfer. Bypassing it may cause output power to degrade. If you have a differential oscilloscope to observe the output you can try.

Yusuf

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AFE7225EVM: Lower cut off frequency