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INA240: Can't find a schematic to import for 240 or 282 in Tina's TI-Test folder.

Genatco
Guru 54087 points
Part Number: INA240
Other Parts Discussed in Thread: INA282, , TINA-TI

Would like to run Tina current direction simulations on INA240 and INA282 but there are no import files for either device? 

  • 0
    TI__Genius 14825 points

    BP101,


    There are two files in the INA240 folder, a TINA reference design file (with the parts in it) and a zip file with PSpice models in it.  The INA282 has the same two files and a third of just the INA282 device.


    Is there a file we're missing?

  • 0 in reply to Jason Bridgmon
    Guru 54087 points

    Jason Bridgmon said:
    Is there a file we're missing?

    Hi Jason,

    There seems to be no INA240/282 zip folder under the Examples, TI Test Circuits or Spice folders  libraries for either device. That of course is via Tina's open folder and file search for the project IC blocks.

    The download zip had a self extracting executable file for Tina installer, nothing else.

  • 0 in reply to Genatco
    TI__Genius 15760 points

    Hi BP101,

    The TI Tests Circuits or Spice Folders libraries are probably not updated.

    For INA240 please go to the following link and click on "INA240 TINA-TI Reference Design". This will download a TINA-TINA reference design that contains the INA240 device and a typical circuit.

    For INA282 please go to the following link and click on "INA282 TINA-TI Reference Design". This will download a TINA-TINA reference design that contains the INA282 device and a typical circuit.

  • 0 in reply to Mayrim Verdejo
    Guru 54087 points
    Hi Mayrim,

    Thanks for FYI but....

    Your links to Tina application do not directly include the INA240/282 example or project folders, unless you just updated the main self extraction zip?

    We have already installed Tina and don't want to reinstall it just to get the INA240/282 examples folders.

    Are your INA240 links correct in the post?
  • 0 in reply to Genatco
    Guru 54087 points
    INA 240 Have to click on Tools & Software too : )
  • 0 in reply to Genatco
    TI__Genius 15760 points

    Hi BP101,

    Yes, the links are correct for both devices. It is under Tools & Folders tab > Models. The .TSC file (Under Models) is not the TINA installer. It is a TINA file that contains the INA240 circuit example. When you open the file you should be able to see the INA240 Reference Circuit in TINA.

  • 0 in reply to Mayrim Verdejo
    Guru 54087 points
    Hi Mayrim.

    It seems the Tina download for the INA240 only had the Spice library files and not the INA240 circuit example (*.TSC) as did the INA282 download. Will try that DL again.

    BTW the INA282 test circuit has REF2 connect to ground and REF1 to B+ seems backwards and creates a high to low edge transition for reverse current flow. My books teach GND into a resistive load is electron flow (reverse current) the opposite Benjamin Franklin discovery is forward current or a higher potential flows into the lower. Does TI take that same stance on current flow?
  • 0 in reply to Mayrim Verdejo
    Guru 54087 points

    Hi Mayrim,

    The Tina INA240 test circuits are resistive test and show a forward current B+ to ground. In an inductive circuit any trashy kickback of field collapse (CCEMF) left over from FET snubber flows to ground as delta (dv/dt) and the reverse inductive load current flows from ground into B+. Tina test circuits truly surprise one as they have no inductors when the INA240 is designed specific to PWM and inductors.

    Can you please explain how a 500mv VMD reference can cause (OUT_Ax) to reach the up to rail +4v? That voltage behavior seems is not keeping inline with described character outlined in the datasheet for REF1/2 inputs powered by an external reference source. It seems tech writer left out a few important words. e.g. IN+ increases up to rail and we are only left to assume they mean up to REF1/2 output threshold?

    8.4.3.1 Output Set to External Reference Voltage Connecting both pins together and then to a reference voltage results in an output voltage equal to the reference voltage for the condition of shorted input pins or a 0-V differential input; this configuration is shown inFigure 27. The output voltage decreases below the reference voltage when the IN+ pin is negative relative to the IN– pin and increases when the IN+ pin is positive relative to the IN– pin. This technique is the most accurate way to bias the output to a precise voltage.

  • 0 in reply to Genatco
    Guru 54087 points

    Ok see something using DC nodal voltages probe shows VMID is really 1.65v, not sure why 500m is showing for the voltage amplifier.

  • 0 in reply to Genatco
    TI__Genius 15760 points

    Hi BP01,

    With the original configuration in the example, VMID= 2.5V and OUT_Ax=2.5V.

  • 0 in reply to Mayrim Verdejo
    Guru 54087 points
    Now see is VMID, I was so close to D even with progressive lenses my stigmatism blended them together. But the real question was what is a voltage amplifier and why does it show 500mv in the box? Perhaps Tina engineers never heard of a voltage reference.
  • 0 in reply to Genatco
    TI__Genius 15760 points
    Hi BP101,

    They just multiplied the Vs * 500mV to get the 2.5V. I have seen the TINA model creators use "500mV amplifier" approach just to allow the customer that wants to have a REF voltage 1/2Vs to modify VS only. Just for simplification. It can get confusing, I agree.

    Maybe for a more clear solution they should show two supplies. One for Vs and one for Vref.
  • 0 in reply to Mayrim Verdejo
    Guru 54087 points

    Hi,

    That makes sense but never considered to multiply 500mv with supply voltage to divide the reference.

    BTW: I think the INA240 model has another issue with the shunts current source missing ground. It might even be a wrong INN/INP  pin has been miss identified in the datasheet. 

    https://e2e.ti.com/support/amplifiers/current-shunt-monitors/f/931/p/583896/2144513#2144513

  • 0 in reply to Genatco
    TI__Genius 14825 points

    It's a little quirk of TINA's VCVS that instead of keeping .5 as .5, it makes it 500m.  When you look at engineering text all day, 500m usually means something like mV or mA but in this case it just means .5, which is splitting the supply in half.  So it's not technically multiplying V*V, just V*.5.  That's how I see it anyway, but you probably already figured that out.

    With regard to the current source missing GND, are you referring to this GND I circled in red, or at another point in the schematic?

    I can't speak for all of TI, but I can say that in our shunt monitor data sheets, we represent positive current flow as an arrow from +Voltage to -Voltage (typically GND).  It seems consistent with the ammeter arrow in TINA, as shown below.

    In that regard, I believe the data sheet is consistent with our device pin naming.

    Here's an incredibly basic example showing the Vinput stimulus vs output voltage, with an A1 device, gain = x20.  I believe it confirms this current-flow polarity.

  • 0 in reply to Jason Bridgmon
    Guru 54087 points

    Jason Bridgmon said:
    With regard to the current source missing GND, are you referring to this GND I circled in red, or at another point in the schematic?

    No I was referring to the 240 project current source was not configured to produce a signal. Definitely not the sine wave you show and seemed to push a 1 amp load into the shunt with no wave form generator. When the current source is removed and ground direct to shunt INN, with an inductive circuit tied to INP the INA240 has a much different transient output relative to the square wave CMM at the shunt.

    Jason Bridgmon said:
    we represent positive current flow as an arrow from +Voltage to -Voltage

    It seems Tina current source indicates forward current (INP to INN) and reverse negative current flow INN to INP. Engineers typically never say positive current in datasheets written for silicon devices, thanks for clarifying.