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Amplifiers forum

Part Number: THS4302
Other Parts Discussed in Thread: THS4303, THS4304, , TL081, LMH6521, LMH6523, LMH6554, LMH2832, LMH6881, OPA857, TINA-TI, BUF802

Hello there,

I am willing to buy THS4302, THS4303, THS4304 op-amps. I came across with few problems listed below:

1. The PSpice model downloaded  from the official website of TI is not compatible with the ADS simulator.

2. When I'm trying to simulate a circuit based on a THS4302 operational amplifier with the ADS simulator. I'm using the official PSPICE model downloaded from:

www.ti.com/.../THS4302

Unfortunately, it seems that it doesn't work due to compatibility issues.
Error detected by hpeesofsim during netlist flattening. 'ths4302.sbias' is an instance of an undefined model 'spice_vswitch'.

3. The PSpice model pin configuration of THS4302,THS4303,THS4304 is not available in datasheet. The  Datasheet should contain pin specification that which terminal is input and output pins etc. then only end-user will be able to simulate the circuit.


For your reference, The Datasheet of op-amp TL081(taken from the TI website)  is having   pin configuration.

Can you please clarify my doubt as soon as possible

  • Hi Rahul,

    1&2. Are you willing to try our PSPICE-for-TI or TINA-TI simulators? These respective models will certainly work in those programs.

    3. The pin configuration is defined in the introductory comments of the THS430X model netlists. For example, here are the pin definitions for the THS4302

    These pin specifications do reflect the pin names used in the THS4302 datasheet:

      

    Best regards,

    Sean

  • Hello Sean

    Thank you for your response.

    1. I was simulating my circuit in ADS simulator where I can do S parameter analysis and also AC analysis.

    2. The simulator suggested by you have this S parameter analysis function?

    3.The pin configuration is defined in the introductory comments of the THS430X model netlists. Yes I agree the pin configuration for real chip is given.

       But I am  talking about pin configuration of P-spice model not the Chip. 

    For your reference I am attaching photos of P-spice model imported in Simulator. My query is  among these 6 pins which one is inverting ,non inverting, output, dc supply pin 

                                 THS4302 pspice model

  • Hi Rahul,

    1. Understood. I will ask my manager if we can start making some ADS models forTI High Speed Amplifiers.

    2. Unfortunately all we have today are SPICE simulation models for these amplifiers. You can use them to simulate the S21 frequency response, and the input impedance that can be plotted on a smith chart to find S11. 

    3. There is usually a step in the import process where you choose what pin on the symbol (1,2,3,...) gets connected to what net in the netlist (IN+,IN-,VS+,...). In PSPICE, (for 3rd party models) there is a file for the symbol image and a separate file for the netlist, and you have to complete this linkage step in "Model Editor" to use that model in a design circuit. Since it is left to the user, it can't really be in the datasheet.

    Best regards,

    Sean

  • Thank you for your response.

    1 please do make ADS model because these day ADS simulator is very popular among researcher.

    I request if you can make ADS model for this THX4302. So i can simulate my structure and can please order opamp . ASAP.

    2. Can you suggest some wave if I am using spice simulator to find s parameter apart from impedance plot.

    I mean any matlab code or other which can be done.

    3. The process of importing  which you told  is for for Spice simulator.

    And one more query

    4. Any solution  suggestion for vswitch error  which i addressed very first in the conversion.

    Regards

    Rahul

  • Hi Rahul,

    1. These HS Amps have ADS models already: LMH6523, LMH6881, LMH2832, OPA857, LMH6521, LMH6554, TRF37X73, and TRF37X75. Maybe you can use one of these in the meantime?

    I don't have good answers for your other inquiries. Hopefully they will be resolved with a new ADS model.

    Best regards,

    Sean

  • These op-amp are working in MHz frequency(small signal gain above 1 dB) but  I need op-amp in GHz frequency if any other upto 4 or 5 GHz op-amp.

    Please let me know.

    And May I know when the ADs model I can get ?

    Regards 

    Rahul

  • We have a new buffer that can reach about 3GHz, it is called the BUF802. I was not able to get management approval to make an ADS model for these devices, but I was able to download the ADS software. It looks like you could use passive components to model an equivalent input impedance to simulate S11. We are not allowed to release the transistor-level models anyways, so even if we did make an ADS model, this is all we would have inside the model for S11 anyways. The S21 is the frequency response and can be found using PSPICE or TINA-TI. Do you also want the S22 and S12? I don't think I can help you with those without a transistor level model.

  • Thank you for your response 

    1. I need to use op-amp only, buffer will not be useful for my circuit.

    2. The main concern of mine is I want to know the pin configuration of THS4303  p-spice model pin shown below. so that response can be generated and then I will be able to order Op -amp

      

    3. The pin configuration of chip is already given in datasheet but not  for the p-spice model shown above

                                                                                         

    Rahul Vishwakarma

  • Hello Rahul,

      1) If you do not need to amplify the signal, a buffer can be used for a unity-gain design/configuration

      2) Sean pointed out in earlier reply that the p-spice model has pin configuration within its netlist/macro file. When importing the netlist and creating the symbol, there is a step within the process that will have you match the pins to the symbol to the pin definitions in the netlist. We wouldn't know these pins of the symbol you have created; since, during the symbol creation you would have set each pin definition. 

      Here is a thread that covers importing PSpice models into ADS simulator. But, would recommend Sean's method.

    Thank you,
    Sima