Hello,
Can the p function be used for symbols other than symbol:MN?
I tried to estimate the losses of a MOS device by creating an embedded Infineon device (symbol:X) and using the p function in a .measure statement, just as I would with symbol:MN, but I got the following error:
no such function p
My questions are:
1. Can the p function be used with symbol:X?
2. If it cannot be used, do I have no choice but to estimate it manually using VdsIds + VgsIg?
Thank you.
No for subcircuit
I have a 3-terminal subcircuit symbol for power measurement designed to fit a MOSFET symbol. Here is an example schematic. You can download this symbol from my GitHub (https://github.com/KSKelvin-Github/Qspice).
/Symbols-KSKelvin/probes and measure/PowerProbe-3Terminals.qsym
example.PowerProbe-3Terminals (MOSFET-Subckt).qsch (10.0 KB)
Thank you.
Does it calculate VgsIgs+VdsIds?
This is how Instantaneous Power suppose to be calculated with multiple terminals device.
Sum of ( node voltage * current into that node)
Here is a concept schematic in making this symbol
Anyway, there is no different in using this formula, or differentiate voltage formula to compute total power. So, it is also calculating Vgs * Igs + Vds + Ids
Your advice always help me.
Thank you.
First time I run the example “example.PowerProbe-3Terminals (MOSFET-Subckt).qsch” it run as intended.
Later on, re run same file I got this error message: “Fatal error: MM•X2: AF must be positive definite.”
Re-install QSpice and restarting PC didn’t resolve it. Any idea what is happening?
Update Qspice again; this bug has just been resolved by Mike. Something went wrong in the previous update regarding flicker noise in MOS, as AF is a flicker noise parameter.
just saw this update commit in the revision history, sweet!
