On 17/03/2025 12:27, Tony Casey wrote:
On 17/03/2025 11:40, Stephano via
groups.io wrote:
using the TI model of LF356 on LTspice v24.1.0 result in strange behaviour, DC output from OpAmp is over 18V when the supply voltages are ¡À 15V.
In the "Component attribute editor" I've changed parameters for this version of LTspice, the original from the file area "LF356_test.zip" result in errors at simulation start.
I want to simulate a input circuit of an test equipment (Boonton 4200) that is oscillating at 93Hz square wave with amplitude near the supply coltages. I'm curious to see the Phase Margin of this differential stage with three LF356.
Clearly this pspice model is incompatible with this LTspice version, or there is a workaround possible to apply ?
I don't have version 24.1.0 installed, but with 24.1.5, the
(Helmut's) original circuit stalled at 40% completion, but was
correct up to that point. When I changed the rise and fall times
of the source to 100n from 10n, it simulated perfectly. With
version 25.0.12, the original unedited circuit had no problems. I
also ran an input voltage sweep and saw the output clipped well
inside the supply voltages.
The version 24.1.0 was quite short-lived because there were a
number of problems with it. There have been many internal changes
in the 24.1.x release. some of these have since been fixed, but
others remain.
It may be that nobody can duplicate the problem you are having,
but if you have changed anything in the schematic, you should
upload it to Files > Temp, so more people can try. Did you
change any of the Control Panel > SPICE settings from default?
The Trtol parameter in 24.1 is different from 24.0 in the default
state.
Adding ".options gshunt=1e-12 cshunt=1e-14" fixed the stalling at
40% issue with 24.1.5.
--
Regards,
Tony