• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 38 subscribers
  • Views 612 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

OPA41040 model

Scott Seidman
Prodigy 20 points
Other Parts Discussed in Thread: OPA140, OPA4140

I'm running this model  (the LIB file downloaded from the tools area on the product page www.ti.com/.../toolssoftware )  in LTspice. I'm powering between 5V and ground, and the op amp is wired as a simple follower.  the input is a 1V sin wave at 10 Hz.  I started with a 2.5V offset on the input, and then moved down to a 1V offset as the output was saturated at about 2.4 V.  It worked just fine with a 1V offset.  Can someone maybe check the model for this rail to rail op amp?  

I know the model must be wrong, but the spurious run is shaking my confidence a bit.

  • 0
    TI__Guru 67601 points

    Scott,

    First, I presume you refer to a quad version of OPA140 thus OPA4140, and not OPA41040. The OPA140 macro-model is correct BUT you violate the input common-mode voltage range. OPA4140 has rail-to-rail output voltage range but NOT the input. See the datasheet table below: on 5V single supply, the linear range of the input signal extends only from -0.1V to 1.5V while you are applying signal from 1.5V to 3.5V thus violating the allowable range by as much as 2V.

  • 0 in reply to Marek Lis
    Prodigy 20 points

    Thanks!  Should have checked first.  Since I was running around 2.5V, I just assumed I'd be in the clear.