ADC128S102QML-SP: Is a buffer required at the ADC input

user1359349

Part Number: ADC128S102QML-SP
Other Parts Discussed in Thread: INA213-Q1

Hello TI engineer,

In one of our projects, we are using the TI ADC chip ADC128S102QML to read the analog signal from the TI current‑monitoring chip INA213BQDCKRQ1, which is used to monitor the current draw of the system power supply.

Our question is:

Can the ADC128S102QML directly read the analog output from the INA213BQDCKRQ1?
Do we need to add a voltage follower (buffer) in front of the ADC128S102QML input?

Please kindly review and advise. Thank you for your help.

5 days ago

0 Joel Meraz 4 days ago

TI__Mastermind 21150 points

Hello,

What is the sampling rate requirement?

Regards,
Joel

0 user1359349 4 days ago in reply to Joel Meraz

Intellectual 510 points

hello Joel

thanks for your replay

For this monitoring application, we anticipate that during normal operation the output analog signal is in the range of approximately 0.5 V to 1 V. In the event of a fault, the output will maintain a high level for several milliseconds or even longer, exceeding the set threshold. Consequently, we consider that a high sampling rate is not necessary, and a rate of 10 kSPS is adequate

0 Joel Meraz 3 days ago in reply to user1359349

TI__Mastermind 21150 points

Hello,

The INA213-Q1 already provides low output impedance, and the low sampling rate allows sufficient time for the input signal to settle. A voltage buffer will not be necessary. An RC filter at the analog input is sufficient, and the current values should perform well.

Regards,
Joel

0 user1359349 3 days ago in reply to Joel Meraz

Intellectual 510 points

That's great news for me. Thank you very much for your reply.

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ADC128S102QML-SP: Is a buffer required at the ADC input