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ISO7720: ISO7720

Surendra Jadhav
Prodigy 20 points
Part Number: ISO7720
Other Parts Discussed in Thread: PSPICE-FOR-TI,

Tool/software:

Hello

I could see that Digital galvanic isolator simulation models are either IBIS model or transient SPICE model.

In order to perform analog simulation, I need Spice/VHDL model of Digital galvanic isolator.

Is it possible to convert transient model to conventional spice/vhdl model. (I believe that transient model shall not yield same results as conventional model).

Regards,

Surendra.

  • 0
    TI__Mastermind 29375 points

    Hello Surendra,

    Thank you for reaching out. Most of the devices should have an IBIS model, and PSPICE models are developed on an as needed basis for the PSPICE-for-TI tool.

    Based on my understanding, there are various terminologies from different SPICE and modeling systems. The model online is a 'conventional' SPICE model if you are looking to simulate the basic functionality of the ISO7720. The model will match the functionality of ISO7720's behavior, and the term "transient" here refers to time-domain simulations. 

    SPICE and VHDL are inherently languages with respect to purpose and simulation capability. Therefore, I do not expect there to be an easy way to convert from SPICE to VHDL. The VHDL is designed to describe logic circuits and not their analog behavior. The model for ISO7720 could be created as a simple buffer or "OUTA <= INA" in VHDL.

    The SPICE model will simulate more detailed analog characteristics such as input thresholds and UVLO.   

    I hope this helps

    Best,
    Andrew

  • 0 in reply to Andrew J
    Prodigy 20 points

    Thanks Andrew for your reply.

    IBIS model would not depict the functionality of digital isolator including galvanic isolation.

    This is very important for me in my analog simulation.

    Basically I am not using TI simulation SW for running analysis. This is the reason I need Pspice model of device.

    Moreover transient Pspice model may not serve my purpose.

    Neverthless, can I get any other Pspice model for galvanic digital isolator.

    Regards,

    Surendra

  • 0 in reply to Surendra Jadhav
    TI__Mastermind 29375 points

    Surendra, 

    The PSPICE transient model should work for all analog simulations using the PSPICE simulator. It is currently our only model. Please attempt your simulation with the transient model. 

    Surendra Jadhav said:

    the functionality of digital isolator including galvanic isolation.

    This is very important for me in my analog simulation.

    Am I correct in understanding that you are hoping to simulate the galvanic isolation in PSPICE? Unfortunately, this is a limitation of PSICE simulations as whole. SPICE needs to have all grounds be resolved to the SPICE ground or '0'. Therefore, simulation of isolated characteristics is not possible.

    Best,
    Andrew