no, actually this is also a 3.3V version .Hi,
is there even a 3 V version of the LM3940 available? I checked several distributers, I couldn't spot a 3 V version.
I'm a little bit confused by the part number of the linear regulator, as it indicates a 3 V output voltage (the .3 at the end is missing). Where does this spice model come from, is it a built in one?
I don't know how accurate the regulator is modeled, but you might test the simulation with a resistor of ~0.5 Ohm in series with C4, see section 22.214.171.124.2 ESR Limits on page 9 in .
See if the LM3940 model in the programme you are using to simulate with has a netlist - if it does, post it here and maybe one of the experts can see what is wrong with the model/simulation set-up.
Did you assign the in, gnd, out pins to the model? (Try swapping in with out, etc.)
Sometimes an AC simulation works where a DC simulation doesn't (but should) or a transient analysis might show Vreg working, or at least show what start-up waveforms look like and give some clues.
ISIS SCHEMATIC DESCRIPTION FORMAT 8.0 ===================================== Design: voltage regulator.pdsprj Doc. no.: <NONE> Revision: <NONE> Author: <NONE> Created: 28-07-2022 Modified: 28-07-2022 *PROPERTIES,0 *MODELDEFS,0 *PARTLIST,6 C3,AVX0603Y5V100N,0.47u,CODE="Farnell 317-287",EID=17,PACKAGE=0603_CAP C4,AVX0603Y5V100N,33u,CODE="Farnell 317-287",EID=18,PACKAGE=0603_CAP D1,LED-RED,LED-RED,BV=4V,DRIVE=1,EID=1,IMAX=10mA,PACKAGE=LED,ROFF=100k,RS=3,STATE=0,TLITMIN=10m,VF=2.2V R1,9C04021A3000FLHF3,1k,CODE="Digikey 311-300LCT-ND",EID=6,PACKAGE=RESC1005X40,PRIMTYPE=RESISTOR U1,LM3940IT-3,LM3940IT-3,EID=5,PACKAGE=TO254P470X1028X1955-3P V1,VSOURCE,5V,EID=3 *NETLIST,4 #00002,3 C3,PS,1 U1,PS,1 V1,PS,1 #00003,2 C4,PS,1 R1,PS,1 #00004,3 D1,PS,A U1,PS,3 R1,PS,2 GND,6,CLASS=POWER GND,PR C3,PS,2 V1,PS,2 U1,PS,2 C4,PS,2 D1,PS,K
Misunderstanding , I meant the netlist for the LM3940 model. It might also be called 'view macro' or suchlike. Maybe right-clicking on it brings up a menu with that option in the simulation tool.
no, i cant see anything what you are saying
these are the options that shown on right clicking model
I couldn't find a SPICE model provided by the manufacturer (TI). If it is Proteus, I could not spot it within the pretty old (2003) library list . The LM3940 is available at least scince 1999.Where does this spice model come from, is it a built in one?