Request for IBIS Models for Simulation

Hi Suraj02 ,

Pure analog parts like the ADA4637 generally do not have IBIS model since they don't have any digital pin. We usually only have LTSpice models for op-amps.

Thanks,

Gio

Hi GioBalgemino , Suraj02 , Geloism16  ,

GioBalgemino said:

We usually only have LTSpice models for op-amps.

Not true. LTspice ships with thousands of models, and exists in a SPICE universe of 10s of thousands of models, where op amps account for only a small percentage of the devices. For instance, one of LTspice's super-powers is the ability to simulate difficult-to-model non-linear systems, such as switching regulators. LTspice also models digital devices, such as DACs and ADCs.

GioBalgemino said:

Pure analog parts like the ADA4637 generally do not have IBIS model since they don't have any digital pin.

That part is true. IBIS was originally developed to present the actions of a digital device as analog pin behavior, eliminating the need to actually simulate the internal workings of a digital device or obfuscate it, i.e. the transistor-level behavior. LTspice is quite good at doing the latter, essentially modeling the behavior of the internal components, and let that drive the pin behavior. But, focusing on the internal workings of a complex digital device might not appropriate for a device with foo-illions of transistors. Maybe this article can help:

https://www.analog.com/en/resources/analog-dialogue/articles/ibis-modeling-part-1-why-ibis-modeling-is-critical-to-the-success-of-your-design.html

mike

Hi GioBalgemino , Suraj02 , Geloism16  ,

GioBalgemino said:

We usually only have LTSpice models for op-amps.

Not true. LTspice ships with thousands of models, and exists in a SPICE universe of 10s of thousands of models, where op amps account for only a small percentage of the devices. For instance, one of LTspice's super-powers is the ability to simulate difficult-to-model non-linear systems, such as switching regulators. LTspice also models digital devices, such as DACs and ADCs.

GioBalgemino said:

Pure analog parts like the ADA4637 generally do not have IBIS model since they don't have any digital pin.

That part is true. IBIS was originally developed to present the actions of a digital device as analog pin behavior, eliminating the need to actually simulate the internal workings of a digital device or obfuscate it, i.e. the transistor-level behavior. LTspice is quite good at doing the latter, essentially modeling the behavior of the internal components, and let that drive the pin behavior. But, focusing on the internal workings of a complex digital device might not appropriate for a device with foo-illions of transistors. Maybe this article can help:

https://www.analog.com/en/resources/analog-dialogue/articles/ibis-modeling-part-1-why-ibis-modeling-is-critical-to-the-success-of-your-design.html

mike