ADS1258: Parasitic Capacitances

jose ramon foronda melo

Part Number: ADS1258
Other Parts Discussed in Thread: LSF0108, ADS1158,

Hi, I'm jose

I plan to use the ADS1258 in a circuit. Basically I'd like to ask about what are the parasitic capacitances associated for each pin of this Integrated Circuit, but more precisely, I need the parasitic capacitances of the pins described below (Fig.1), because I need to use a Voltage Level Translator (LSF0108) for those pins, and the speed of this LSF0108 is influenced with these parasitic capacitances throught an R*C relationship where I need to get a proper value for the resistor (R)

Fig.1. pins description

Thank you for the help

over 6 years ago

0 jose ramon foronda melo over 6 years ago

Prodigy 230 points

It seems there are problems to display the image I attached. So I add in this reply the image with the pins.

0 Bryan Lizon86 over 6 years ago in reply to jose ramon foronda melo

TI__Guru 58971 points

Hi Jose,

Check out the IBIS model for the ADS1158, which is just the 16-bit version of the ADS1258. This contains pin capacitance values as I have shown below. Looks like it varies between 0.52 and 0.58 pF.

-Bryan

0 jose ramon foronda melo over 6 years ago in reply to Bryan Lizon86

Prodigy 230 points

Hi Bryan,

This information has been very useful, thank you so much for your time helping me with this.

Additionally, as I'm a bit new with this topics I'd like to ask: would I be able to generate a file with this kind of information for any IC that I can use in the environment of simulation (PSPICE ?? I think that's the name)?

Thank you

0 Bryan Lizon86 over 6 years ago in reply to jose ramon foronda melo

TI__Guru 58971 points

Hi Jose,

Many ADCs from Texas Instruments already have the IBIS models included on the device product folder. These are contained within the "Design Tools & Simulation" section under the "Design & Development" heading. So, if you need a model for a specific device, that would be the best place to check. Below is an image showing where I found the ADS1158 IBIS model that I linked to in my previous post - these would be in a similar location for any ADC that currently has one.

You can also learn more about IBIS models from the links in this e2e post: https://e2e.ti.com/support/data-converters/f/73/t/861714

-Bryan

0 jose ramon foronda melo over 6 years ago in reply to Bryan Lizon86

Prodigy 230 points

This post has been very useful for me. Bryan, really thank you for this explanation and for the referenced guides to understand better the IBIS models. I'll read those guides in that post!

Thank you for the help

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ADS1258: Parasitic Capacitances