ADS7830: What is the input impedance of each analog input channel?

Hui Chen

Part Number: ADS7830

Hi TI experts

What is the input impedance of each analog input channel? I can't find any information for the input impedance of analog channel in the ADS7830 datasheet. Could you help clarify this impedance value?

Regards

Chenhui

over 4 years ago

0 Cynthia over 4 years ago

TI__Mastermind 25020 points

Hello

The ADS7830 is a SAR ADC, this means that is uses a switched capacitor circuit to sample input, this means that input impedance is dynamic and depends on the sampling rate. This is why the impedance is not specific in the datasheet.

Regards

Cynthia

0 Hui Chen over 4 years ago in reply to Cynthia

Intellectual 430 points

HI Thanks for your reply.

Then, whether the relation formula between sampling rate and input impedance can be given? Alternatively, a general range of input impedance is OK too.

Regards

Chenhui

0 Cynthia over 4 years ago in reply to Hui Chen

TI__Mastermind 25020 points

I suggest looking at the settling time based on your clock rate, I feel this will be more helpful.

A basic R=1/CF would be an estimate, but again, I could not imagine where this would be helpful

Regards

Cynthia

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ADS7830: What is the input impedance of each analog input channel?