ADS8528: One analog channel affecting another channel -- is this possible?

Saurabh Tewari

Part Number: ADS8528
Other Parts Discussed in Thread: ADS8588S

Hello everyone,

We are using ADS8528 with a 2.5V external reference, and with the RANGE pin pulled up to 3.3V (with a 10 Ohm). This yields a measurement range of +/-5 Volts. Whereas the HVDD and HVSS power supplies are +/-7.5 Volts.

All the analog inputs are driven from opamps followed by a RC circuit. On one analog input, the driving opamp can occasionally enter saturation and output -7.5V. My question is twofold:

Is there any risk of damaging the ADC?
Is there a chance that one channel entering and and leaving saturation would affect an adjacent channel that is receiving a signal within the +/-5V?

Thank you.

Regards,

over 5 years ago

0 Dale Li over 5 years ago

TI__Mastermind 48035 points

Hi Saurabh,

If the opamp's output can be guaranteed no higher than HVDD or lower than HVSS of ADC, the ADC will be safe, please see the absolute maximum ratings table in the ADC datasheet.

Channel-to-channel crosstalk is possible, unfortunately ADS8528 does not have a crosstalk specification. However, the latest ADC, ADS8588S which is a 16-bit,8-channel, simultaneous-sampling ADC with integrated PGA and LPF on each channel, has crosstalk specification in the datasheet.

Best regards,

Dale

0 Saurabh Tewari over 5 years ago in reply to Dale Li

Intellectual 670 points

Thank you Dale.

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ADS8528: One analog channel affecting another channel -- is this possible?