sonar data converter/AFE, 20-150 kHz bandwidth

Sarah Patch

Other Parts Discussed in Thread: AFE5808A, AFE5809

2-stage amplification with TI 1642A amplifier, works well and achieves about 300x (48-50dB) gain of signals around 50 kHz.

My acoustic signals have frequency content over 20-150 kHz, and we test at 50 kHz.

Input acoustic signal amplitude is O(10 microV) so any amplifier that we use must be sensitive to very weak voltages.

Now, the next step will be to create a multi channel DAQ to avoid reading out on a digital oscilloscope.

Or to find an appropriate AFE with equivalent or better low noise amplifier and AD?

At this research stage, I prefer that raw data be saved for offline analysis. When we are very confident of the signals we receive we can consider adding some basic processing steps on the chip.

Having said all that, I see that very low frequency performance can be achieved for your ultrasound AFE5808A

https://e2e.ti.com/support/data-converters/f/73/t/902865?tisearch=e2e-sitesearch&keymatch=AFE%205809

Is noise as low as for the 164* family of amplifiers?

A compact footprint would be great, so the AFE5808A sounds appealing.

Finally, how does the 5808A compare to 5809?

Please reply with your suggestions.

over 3 years ago

0 Chen Kung over 3 years ago

TI__Genius 12025 points

Hi,

Thank you for choosing TI AFE devices.

Here is our group suggestion:

=========================

AFE5809 is better . it is more stable when they disable all HPFs in the chip.

=========================

Thank you!

0 Chen Kung over 3 years ago in reply to Chen Kung

TI__Genius 12025 points

Hi,

also please refer to the following app note:

we have app note .

https://www.ti.com/lit/pdf/tidu702

0 Sarah Patch over 3 years ago in reply to Chen Kung

Prodigy 30 points

Dear Chen,

Thank you very much for your response. My concern is that it looks as though it doesn't do very well with frequencies below 100 kHz. The plot in Fig 5.4 concerns me - even for the "red" curve for low frequency settings. ALSO, I want raw data, not beam formed data.

Does TI offer some sort of truly sonar - or audio - data converter that simply amplifies and sends directly to A/D?

Thank you for your information,

Sarah Patch

0 Sarah Patch over 3 years ago in reply to Sarah Patch

Prodigy 30 points

I should have written Fig 19 in section 5.4!

0 Chen Kung over 3 years ago in reply to Sarah Patch

TI__Genius 12025 points

Hi,

For your concern using AFE5809, on the Figure 19 section 5.4,

it does not cover very detail information,

for more detailed description as follows:

with INM capacitor (Cbypass) = 15nF, the LNA cutoff freq=100kHz

with INM capacitor (Cbypass) = 22nF, the LNA cutoff freq=70kHz

with INM capacitor (Cbypass) = 47nF, the LNA cutoff freq=33kHz

with INM capacitor (Cbypass) = 1uF, the LNA cutoff freq=2kHz

Notice: PGA_HPF_Disable='1', HPF_LNA="01"

Thank you!

0 Chen Kung over 3 years ago in reply to Chen Kung

TI__Genius 12025 points

Also, please the datasheet page 1,

as you can see you can receive the raw data with only ADC output to LVDS if you want.

Thank you!

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sonar data converter/AFE, 20-150 kHz bandwidth