UCC27526 .lib file

Other Parts Discussed in Thread: UCC27526

Dear


the .lib model of UCC27526 works only if GND is connected to the simulator GND. If I connect the GND of the UCC27526 model to a different voltage potential (ether floating or fix potential, unless direct connection to GND of the simulator), the model stops working. I tried to "raise" the voltage potential of the UCC27526 with a voltage generator that has 0V, but it still does not work. How can this problem be avoided. I am using LT Spice. For the rest TI .lib files the LT spice work normally worked normally.

Thank you, 

Zajc

  • Hello Zajc,

    Thanks for reaching out.

    Our buffer models do not support floating conditions as the GND reference is tied to true GND 0V. The model will therefore not support this configuration. 

    As workaround, you may simply implement a push pull configuration with some discrete transistors to source/sink current at the gate (I assume you're driving a a power transistor).

    Thanks.

    -Mamadou

  • Dear Mr. Mamadou, 

    thank you for your answer. It is extremely difficult to implement the push pull configuration instead of UCC because of the timing difference between the triggering of the floating and GND power transistor. Is there way to adapt the model uf UCC not to be necessarily tied to true GND?

    Best, 

    Zajc

  • Hello Zajc,

    Thanks for following up.

    I will get back to within 24-48hrs.

    Regards,

    -Mamadou

  • Hello Zajc,

    I still need more time, I should get back to you before COB Friday.

    Meanwhile, I have sent you a friend request where I will follow up with you separately.

    Thanks.

    Regards,

    -Mamadou

  • Dear Mr. Mamadou, 

    have you found any solution yet?

    Best regards, 

    Zajc

  • Hello Zacj,

    Thanks for the follow up.

    You may use the model with external level shifters at the input and output pins of the IC. Level shifting can be done by using voltage controlled voltage sources (VCVS) to interface the model input and the signal of interest.

    For the input pins, the positive input terminal of the VCVS is connected to the signal of interest and its negative input terminal is connected to ground pin.

    Similarly on the output, the pins are referenced to 0V which will also require to shift them up by new "ground" value using the VCVS to establish the desired floating conditions.

    I hope this addresses your inquiry.

    Best,

    Mamadou