Question: ![schematic](https://i.stack.imgur.com/4YP5J.png)

[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2f4YP5J.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)

LM358

positive rail: 24V

negative rail: -1.250V

Input voltage: -1.250 - ~20V

* Is this the right way to switch between gain of 10 and no gain (simple buffer)?
* \$G = 20/2.2 + 1 = 10.09\$ still not a 10, is there a better combination of **standard** resistors values to achieve gain of 10?

Answer: 
Current draw / power in a SPICE model for an opamp macromodel *is* modeled for virtually all the real devices I have ever used, but beware; the values will be (almost universally) the *typical* values from the datasheet for quiescent draw and will use the nominal internal paths for all other power (such as output loading).

There are some models that do *not* have this information so be careful; the quiescent current will normally be a I device (current source) or a G device (Voltage controlled current source) and perusing the file can show if it is present (The G device in this model is used because it has a shutdown feature).

Here is an extract from the MAX4236 datasheet:

[![MAX4236 Quiescent current](https://i.stack.imgur.com/bSyR7.png)](https://i.stack.imgur.com/bSyR7.png)

As you can see, the *typical* supply current is 350 uA.

Here is part of the SPICE model for the same part:

> 
> \*SUPPLY CURRENT
> 
> 
> \*BIAS CURRENT  
> 
>  DSUP 18 10 DB
> 
> 
> ISUP 10 18 0.1UA
> 
> 
> GSUP 10 18 52 20 350U
> 
> 
> 

GSUP is indeed 350 uA in this model.

There is an excellent [application note](https://www.analog.com/media/en/technical-documentation/application-notes/an48.pdf) (somewhat old but still perfectly valid) that goes into some detail on just what is actually within the macromodels.

So generally the quiescent current is modeled but always check.

If the power pins are listed at the start of the file as they are here:

> 
> * ---
> * Connections
> * 1 = OUT
> * 2 = VEE
> * 3 = IN+
> * 4 = IN-
> * 5 = SHDN\
> * 6 = VCC
>  
>  
> 
> ---
> 
> 
> .SUBCKT MAX4236 1 2 3 4 5 6
> 
> 
> 

Then the quiescent current very probably *is* modeled.
No, it is not safe to say that. Some models are **ideal** models and don't even have power supply connections. You must verify that the model you decide to use properly simulates whatever behavior you care about. Assume nothing.