AC coupled input for SD24

Alpha,
Can you provide some more information regarding Vin; source impedance, voltage levels, drive strength? I think it would be best to simulate, but I am concerned that this configuration would allow the the input to go negative (below the device Vss).

Thanks,
Chris

Chris Sterzik said:

I am concerned that this configuration would allow the the input to go negative (below the device Vss).

Chris,

Note that (some) SD24 does allow negative input. One particular I know is SD24 of msp430i2xxx series, it works down to AVSS-1 V (as per datasheet).

Thanks llmars. I was referring to the Absolute Maximum Ratings in the datasheet which states -0.3 to Vcc+0.3V. I will look into the difference.

Regards,
Chris

Dear Chris

Thank you for your response.

I got feedback from customer regarding your inquiry.

<Input signal condition>
- 1mVp-p
- Sine wave input
- Customer want to use AC coupled circuit to cancel DC parameters.

Are there any reference design if customer used AC coupled circuit?

Your reply would be appreciated.
Thanks and best regards.

It would be better if u can simulate the circuit by TI-TINA. By this way, u can tune all resistors to get what u need.

Hi Chris

Wouldn't you recommend SD24 if it was used ac coupled circuit?
If not , please provide reference ac coupled circuit .

Thanks and best regards.

alpha said:

Wouldn't you recommend SD24 if it was used ac coupled circuit?

To sample signal using AC coupled buffer, you do not necessarily need SD24.  Further reading

Hi Ilmars

Our customer is considering to reduce gain amp using delta-sigma A/D.
Because delta-sigma A/D has high dynamic range.

As you mentioned , their current system is used SAR A/D with gain amp.