yrrapt
09/23/2021, 7:37 AMTim Edwards
09/23/2021, 1:02 PMsky130.lib.spice
file has numerous corner sections relating to monte carlo simulation. Each simulation corner has a corresponding mismatch analysis corner, such as ff_mm
for transistors, or ll_mm
for resistors and capacitors, which will perform device mismatch. For monte carlo process variation, use the corner mc
, which will then randomize process parameters on each run. Note that there is no mixture of front-end and back-end mismatch; the front-end corners use typical back-end parameters, and the back-end corners use typical front-end parameters. If more corner types are needed (such as ff
for transistors plus ll
for resistors and capacitors), you can always spin your own version of sky130.lib.spice
.
The proper invocation for the file in a SPICE netlist is .lib /_path_/_to/_sky130.lib.spice _corner_
, e.g., .lib /usr/share/pdk/sky130A/libs.tech/ngspice/sky130.lib.spice tt_mm
for transistor mismatch analysis at the typical process corner.Chen Zach
09/23/2021, 2:53 PMyrrapt
09/23/2021, 2:57 PMTim Edwards
09/23/2021, 2:57 PMChen Zach
09/25/2021, 11:06 PMTim Edwards
09/26/2021, 1:58 AMtoxe
for the device in question and figure out what scaling was applied to the gaussian (e.g., sky130_fd_pr__nfet_01v8__toxe_slope
). I can only advise that I took the spectre models, and where they had, for example, vary _parameter_ dist=gauss std=1.0
, I parsed through the device model and replaced parameter
with MC_MM_SWITCH*AGAUSS(0,1.0.1)
, which I believe to be the equivalent ngspice expression.Chen Zach
09/26/2021, 2:34 AMChen Zach
09/26/2021, 2:39 AMChen Zach
09/26/2021, 3:48 AMTim Edwards
09/26/2021, 4:28 PM1/sqrt(l*w*mult*(1 + HSPICE_SWITCH*1e12))
.Chen Zach
09/26/2021, 4:45 PMTim Edwards
09/26/2021, 4:47 PM.option scale
in one of the library files (all.spice
, I think, or something included from that) that sets the scale. It is not specifically an ngspice thing.Chen Zach
09/26/2021, 4:49 PMChen Zach
09/26/2021, 4:50 PMTim Edwards
09/26/2021, 4:52 PMChen Zach
09/26/2021, 4:53 PM