Hello all, anyone know what is the cause of this error. I am trying to make DC analysis of a typical LDO.

Hi, @Eslam Morsie circuit seems correct, did you provide a voltage source for the 'Vref' node? Open the ERC window (View -> Show ERC window) and read the messages after generating the spice netlist, may be you get some warnings, I don't have other suggestions.

yes I write it in spice netlist Ref Vref 0 0.9

correct syntax is

VVREF VREF 0 0.9

. The line you posted adds a 0.9 ohm resistor

ok thanks

check syntax also for Vin

Vinput Vin 0 2.7

ok

@Stefan Schippers Please sir could you make us a video tutorial how to annotate parameters such as gm vds vgs .etc of a transistor. I didn't understand from the manual.

if you downloaded the

xschem_sky130

libraries open

sky130_tests/test_analog.sch

, it shows how to backannotate transistor data.

@Stefan Schippers ok thanks