#409 Symbol calculated resistance on fixed width high poly resistors does not appear correct Issue created by mhommelga There is a large discrepancy between the calculated resistance (from L & W parameters) on the high poly resistor symbols depending on whether the fixed width or custom width symbol is used. Attached picture shows the issue and also shows that xhigh poly resistors match perfectly. Example: Custom Width: Symbol: res_high_po W=1.41um L=10um Rcalc=2251 Ohm FIxed Width: Symbol res_high_po_1p41 (W=1.41um) L=10um Rcalc=1632Ohm In some cases the values differ by 5x and the custom width resistors appear to be more realistic values and better match the simulation model. However for LVS to work on the layout I have, I need to use the fixed width resistors in the schematics. RTimothyEdwards/open_pdks

@Stefan Schippers The sheet resistance for

res_high_po_?p??

varies according to the fixed width as described here. The nominal values for 1 square are different than the values in the xschem symbols:

width pdk(nom)   symbol
0.35   964        1112 
0.69   738         491 
1.41   586         230
2.83   457         114
5.73   395          56

Are the symbol values actual simulation values for a L/L shaped device?

@Mitch Bailey: The sheet resistances under "symbol" are already divided by the width, but the expression in the symbol that is evaluated to get the estimated resistance again divides the value by the width, so the value is off by a factor equal to the resistor width. I posted a note to Stefan Schippers in #xschem to alert him to the error.

#409 Symbol calculated resistance on fixed width high poly resistors does not appear correct Issue closed as completed by mhommelga RTimothyEdwards/open_pdks