REF 195 spice model association to symbol

[Ridis]

I need to use REF 195, a voltage reference with 5 V output.

I made the symbol and I found the model (attached) in Analog Devices site.  I make a simple circuit (attached) with the symbol but simulation don't give correct results.

I think the problem arises from Pin Mapping Table: symbol has 4 pins and Mapping Table allow only pins 1, 2, 3, 4 for model. Instead in model you find pins 2, 3, 4, 6. Finally I can't connect +5 (Vout) pin in symbol with pin 6 in model.

Am I right ?

Is there a way to overcome Pin Mapping Table and "connect" manually pins in symbol and in model, using any number ?

[NatashaB · Accepted solution]

The values in the model's Pin Mapping Table represent the order of the pins as specified in the subcircuit model, and not the actual pin numbers themselves.  Referring to the attached model (and using the symbol names you specified), the ordering should be VS(1), SD(2), GND(3), +5(4).  I tested it out, and am correctly seeing +5V at the output.

Message Edited by NatashaB on 04-22-2009 10:59 AM

[NatashaB]

Also, you may want to change your simulation settings to gear depending on how you intend to use this model.  To do this, go to Simulation > Interactive Simulation Settings.  Under the Analysis Options tab, select Use Custom Settings, and click Customize.  Under the Transient tab, change the Integration method from trapezoidal to gear.

Message Edited by NatashaB on 04-22-2009 11:34 AM

[Ridis]

Thank you very much.

It works also for me but only with capacitor connected to output otherwise the output oscillate. 

It's not so clear to me the difference between "integration" and "gear" and how to choose. Anyway it seems that "gear" stop oscillations also without output capacitor.