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.

TLV172: Simulation in Orcad Pspice

Part Number: TLV172
Other Parts Discussed in Thread: AMC1300, TINA-TI, THS4151, , THS4531A, THS4561, THS4551, THS4131, OPA172

Dear sir,

we are trying to create the same circuit in pspice. 

The TI-TINA reference design runs good and we are getting expected output. We are trying to create the same file in Orcad Pspice. unfortunately we are getting the convergence error. 

Attached the files for your kind reference.

Thanks & regards,

Rajasekaran

3438.amplified measurements.zip

1346.AMC1300 with TLV172.TSC

  • Rajasekaran,

    I also had issue with the AMC1300, try changing between zero condition start and resolved operating point start.

    If that doesn't work then AMC1300 can be replaced with a fake signal to test the rest of the circuitry.

    1346.with TLV172.TSC

  • Dear sir,

    We replaced the AMC1300 into reference sine waveform as input to the amplifier. The amplifier circuit is working in TINA-TI. But the same circuit is not working in Orcad PSpice. 

    Kindly we request you to confirm the circuit for amplifier in orcad. 

    Thanking you.

    Thanks & Regards,

    Rajasekaran.

    Amp_Measurement.zip

  • Dear sir,

    we faced an issue with TLV172 amplifier running in orcad. So we tried to use THS4151 fully differential amplifier.

    The circuit parameters are,

    Measurement range : 0 to 75A

    Shunt resistance : 1mOhm

    AMC1300 High side voltage : 75mV

    AMC1300 low side voltage : 615mV.

    this voltage is given as input to THS4151 FDA having the gain of 10. 

    The amplifier output voltage is 6.11V (in simulation). we are using +12V & -12V Power supply. 

    Kindly verify the below circuit and confirm us to proceed further in the PCB design.

    Thanking you.

    Thanks & regards,

    Rajasekaran.

    AMC1300 with THS4151.TSC

    ths4151.TSM

  • Rajasekaran,

    It looks good to me, however, the THS4151 is a very different amplifier that is supported by high speed amplifier team. I suggest starting a new thread with that part number to get the best support for that device. 

  • yes if you are moving to an FDA solution, you should consider some of the more recent parts

    1. you do not need split supply, single is fine usually - The common mode loop will handle CM level shifting. 

    2. why are you using +/-12V supplies, what output swing do you need, 

    in ascending speed order, look at 

    THS4531A

    THS4561

    THS4551

  • hi,

    we prefer to have output signal in the range of -10 to +10V. This output signal is given  as input to another analog input module having the input range of +/-10V.

    Kindly suggest the suitable FDA for the same. 

    Thanks & regards,

    Rajasekaran.

  • That is a pretty high input range, 

    So for differential it does get confusing, 

    If each input of module takes +/-10V,then the full differential input range is 40Vpp - really? 

    Perhaps what the module spec means is +/-10V differential, then each input is +/-5V and the THS4561 is plenty for that. 

    If you really want each output of the FDA to be producing +/-10V, look at the THS4131 low noise FDA - but watch out for slew limiting on such a large swing. The original OPA172 is only 10MHz GBP, or about 1Mhz in your gain of 10, so your input signal must be pretty slow. 

    And yes, this discussion is far away from the OPA172 title, can you close this one and start one more like FDA output interface to AMC1300

  • Hi,

    We are unable to find THS4561for ordering in mouser /digikey. So we are proceeding with  THS4151 model. 

    as suggested, created a new post with AMC1300 and THS4151. (link)

    Please check the circuit and share your suggestions. 

    Thanks &Regards,

    Rajasekaran.

  • I guess you didn't look at the THS4131. 

    The THS4561 is available as a sample request from TI.