ADS1602: Harmonic at low frequency

Yoshitaka Kotani

Part Number: ADS1602

Thank you for your help.
I am using Figure 43 for internal reference.
For frequencies of 20 Hz, second and third harmonics are worse than 80 dBc.
Is there a way to improve it?
In such a case, does it need to adopt an external reference circuit?

over 7 years ago

0 Keith Nicholas over 7 years ago

TI__Guru 52100 points

Hello,

I am not sure that we have any data at these low frequencies. I will need to research what we do have. I will provide an update by end of business on Monday.

You mentioned 20Hz, are you possibly getting 50/60Hz line voltage noise into your readings?

Regards,
Keith N.
Precision ADC Applications

0 Keith Nicholas over 7 years ago in reply to Keith Nicholas

TI__Guru 52100 points

Hello,

I have not been able to find any data at 20Hz up to this point. I still have more data to go through, and if I find anything, I will provide an update.

Regards,
Keith

0 Yoshitaka Kotani over 7 years ago in reply to Keith Nicholas

Prodigy 80 points

Hello
thank you for your comment.
I am using the ADS162 for the design of the lock-in amplifier.
It is not influenced by 50 Hz / 60 Hz.
It was found that characteristics are improved when 10 μF in FIG 43 is changed to 1000 μF.
There may be weakness when exposing the internal reference circuit.

0 Yoshitaka Kotani over 7 years ago in reply to Keith Nicholas

Prodigy 80 points

Hello
Thank you for your comment.
I am designing a lock-in amplifier with ADS 1602. Line noise is avoided.
It was improved by changing the capacitor 10 uF to 1000 uF in Figure 43.
We expect the internal reference circuit to be weak.

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ADS1602: Harmonic at low frequency