TINA-TI: Component not available in TINA

Hi Art,

Sometimes we do not create separate models for family members such as OPA187, OPA2187 and OPA4187 when they are electrically equivalent single, dual and quad versions of the same amplifier. That happens to be the case for the OPA187 family. You will note on the OPA187 web page that the Design Tools & Simulation lists the model as "OPAx187" where the "x" is the place holder when the OPA2187 or OPA4187 model is desired.

Other times, an effort was made to have a separate single and dual op amp model such as the OPA189 and OPA2189. However note that the electrical circuits inside these two models are the same and the only difference is the labeling shown by each model, OPA189 or OPA2189. The latter doesn't bring up a dual op amp symbol. What was done came down to the discretion of the model builder at the time.

Nearly all single op amp simulation model symbols have 5 pins, even though the actual package may have 8 or another number of pins. Since 3 of the 8 pins in the op amp often have no function they are not included in the symbol to simplify things. If these 3 pins are added to the Spice symbol they would need to have internal connections, and those would require they be required to be connected to something else in the circuit. If the op amp does have internal connections to those otherwise unused pins, then the pins may be added if it is deemed they have a significant effect on the models behavior or provide some other an important function.

The way Spice users such as TINA-TI Spice handle a dual op amp such as the OPA2187 is to use two OPA187 symbols. Yes, symbol each will be labeled OPA187 and each will have a V+ and V- pin. Just connect each like supply pin to their appropriate supply.

Regards, Thomas

Precision Amplifiers Applications Engineering