Akunuru Venkata Naga Kalyan Ram,
Cadence PowerSi can graph capacitance and inductance
separately when viewing extraction results as RLGC, and in
some cases may display either / both as negative at some
frequencies. As I understand, interpretation of negative
inductance would be capacitive, and interpretation of
negative capacitance would be inductive. I wouldn't expect
to see them both negative at the same time. This
presentation isn't generally relative, as capacitance and
inductance cancel each other. What would be more relevant is
impedance along with phase. That would say both what the
impedance is and whether it is capacitive, inductive, or
neither (when at 0 degrees). For more information, your
Cadence FAE should be able to assist.
I consider PowerSi achieves reasonable results for
extractions when properly set up, but its display of results
to be somewhat funky. Typically I'll take the PowerSi SnP
output file and use it for simulation with another tool,
like ADS, for more flexible display options.
Regards,
Ivor
On 1/15/2020 8:20 AM, Akunuru Venkata Naga Kalyan Ram wrote:
Hello SI/PI Altruists,
I have a question regarding Power Plane loop Inductance phenomenon. I have a*
6'x6" board with 2 layers* (Power and GND planes) and I have defined 2
ports , each one on each edge of the board like a edge connector.
I am using a third party tool to do the simulation and the results show
that the *loop inductance* has a peculiar resonance below 200 MHz and the
value goes to -400 nH.
What is this phenomenon? What does the negative value of Inductance imply?
Can inductance value be negative?
Thank you in advance.
