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Frequency Response of BJT
Posted Mar 25, 2018, 1:07 p.m. EDT Semiconductor Devices Version 5.3a 1 Reply
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Hi
I simulated a model of PNP Bipolar Junction Transister which is lateral structure. But I got an error: Undefined value found. - Detail: Undefined value found in the equation residual vector. There are 53 degrees of freedom giving NaN/Inf in the vector for the variable comp1.Ne. at coordinates: (2.12084e-006,-1.21751e-008), (2.14296e-006,-2.5638e-008), (2.08146e-006,-1.11896e-008), (2.10055e-006,-2.33647e-008), (2.04712e-006,-9.28644e-009), ... There are 51 degrees of freedom giving NaN/Inf in the vector for the variable comp1.Ph. at coordinates: (2.12084e-006,-1.21751e-008), (2.14296e-006,-2.5638e-008), (2.08146e-006,-1.11896e-008), (2.10055e-006,-2.33647e-008), (2.04712e-006,-9.28644e-009), ...
I used base current, collector current and emitter voltage in stationary step and physics setting in frequency perturbation.
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Dear Ziming, For the current driven model to solve, you need to supply a good initial condition from a voltage driven model. Please see this tutorial for an example:
https://www.comsol.com/model/bipolar-transistor-14615
Please feel free to contact support if you need further assistance.
Sincerely, Chien