ADS52J90: input impedance

Dennis Brown

Part Number: ADS52J90

For the ADS52J90, has there been any data measured to show what the differential input impedance looks like, say up to 50MHz or maybe 100MHz between the INP/INM inputs? What were the conditions of the measurement(s) if known?

Also, has there ever been a model (spice) produced that resembles the input impedance but INP/INM inputs?

As an aside, this is an example of what I am looking for: www.analog.com/.../AN-742.pdf

over 7 years ago

0 Praveen Aroul over 7 years ago

TI__Mastermind 49986 points

Hello,

Welcome to TI E2E forum!

Regarding your questions related to ADS52J90, we do not have the data measured for the differential input impedance.
Please refer to Figure 86 of the datasheet for the input sampling network.

0 Dennis Brown over 7 years ago in reply to Praveen Aroul

Prodigy 230 points

Hi Praveen

Thanks for the reply.

In order to get an idea of input impedance via simulation, in figure 86 would the gates labeled S and SZ be sequenced such that "S" is on while "SZ" is off (and vice versa)? In other words, they would generally not be on at the same time?

I would most likely not use a mosfet model but rather a switch with the listed Ron. It would be just a matter of having S and SZ properly sequenced.

0 Praveen Aroul over 7 years ago in reply to Dennis Brown

TI__Mastermind 49986 points

Hi,

Yes the switches marked S and SZ are not on at the same time.
I am closing this thread. Please let us know if you have any more questions.

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ADS52J90: input impedance