How to import SPICE model in ADS?
1. To import SPICE file in ADS, open a schematic and click on File->Import and click on More Options to select the format of SPICE file like PSPICE, SPICE2G, SPICE3G, Spectre, HSPICE etc..normally AD8235 type of models are provided in PSPICE format.
2. Browse to the spice file and click OK. Once done you will see few designs getting added to your project such as AD8235, ampa and ampb in our case because AD8235 spice files contains 2 sub-circuit level spice file models namely ampa and ampb.
3. Don’t try to open these files as they will appear in Nodal connections format and you won’t be able to understand it comfortably.
4. Place the main design such as ad8235 as a sub-circuit on main design where you can design the circuit around this component. See AD8235_Design in attached project where I have placed the AD8235 design as a sub-circuit.
5. Pls note when you place the design as sub-circuit you will see a black box with number of terminals (marked as 1,2,3…) as mentioned in SPICE file. In order to understand which Pin is for what connection you can open AD8235 and look at the ports placed..normally they will the marking/node names as mentioned in datasheet e.g. vin-, vin+, sdn etc etc
6. In order to give you more clarity I have created a symbol which looks similar to one in the datasheet which shall help you identifying the pins for connections easily….It’s another topic to describe “How to create custom symbols”