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16 Threads found on Abstol
Well, LTSpice lives for that kind of thing. You might have to play with settings as you are doing. Whether reltol is the important one, I somewhat doubt - you have others like chgtol (charge) and abstol (absolute) which may be more significant to nodes with low capacitance and high "forward sensitivity" respectively, vntol for node voltages and s
Can you share the circuits (as suggested by Mvaseem) or complete circuit (where two of these modules are connected)? This would enable people to have a closure look. Meanwhile - try following setting and see if this helps - ITL4= 40 - abstol=1n - RELTOL= 0.005 MAX TIME STEP = 50n --- If this works, in next run try increasing this to higher valu
Did you already try different .IC values, e.g. .IC v(a1)=1 ? Or reduce the default abstol value: .OPTION abstol=1e-12
Hi, I've been working on a power device macromodel based on abm, but I got stuck in convergence issues (transient analysis) when Vdd goes over 100V I changed RELTOL, abstol, VNTOL, etc., but I wasn't yet able to have it working with higher voltages. The model is in the attached pdf. I am using PSPICE from Cadence SPB v16.3 Any ideas? T
Hi everyone, In order to solve the convergence problem in my simulation, I wish to set some simulation parameters in Cadence ADE as what I did in Hspice. The parameters that I wish to modify is as follows: abstol = 1n CHGTOL = 1p GMIN = 1n ITL1 = 5000 ITL2 = 5000 ITL4 = 5000 ITL5 = 0 RELTOL = 0.01 STEPGMIN Y However, I can not find
Try changing following parameter ITL4: Increase this to 40 from 10 abstol make this to 1n instead of 1p If this still not resolved, Try using ─UTOCONVERGANCE"
Circular Integrator Operator Use the circular integrator operator to convert an expression argument into its indefinitely integrated form. idtmod(expr [ , ic [ , modulus [, offset ) expr is the dynamic integrand or expression
They are solution constraints on the simulator and will have default variable values set, but you should be able to bump them around as any other variable (in a SPICE) or at least via some option menu (like Spectre). What particular simulator? There are more than RELTOL and abstol, I have also seen CHGTOL (good for circuits that -need- to
Hi, i programmed a model in matlab which requires solving differential equations numerically. i used the commands options = odeset('abstol',1e-20,'RelTol',1e-4); = ode15s(@odes, , icval1, options); and wrote the eqns. I have attached the results where i expect a difference. In the image 1.jpg, there are 2 graphs. However, if
Increase the accuracy of the simulator: reltol, abstol, etc
It looks like u need to relax ur convergence criteria, as the simulator couldn't find a solution within the specified criteria even when using the minimum allowed time step. An easy solution is to use Moderate or Liberal setting when choosing the transient analysis, a better solution is to change the reltol,abstol and relref settings in order to
To get accurate results you will have to select reltol and abstol values several orders of magnitude smaller than the default values. Then do the transient analysis for an exactly integer number of input sine wave cycles. Then do the FFT option. (This is what is done in PSpice, and HSpice may be very similar.)
I use a very old version of orcad that uses ascii text input and so use the .options command. If you use a newer version look in the help menu for words like reltol and abstol. These are relative tolerance and absolute tolerance.
Heres a simple one. The circuit has been tweaked a little in order to make the lamp ligthing quite smooth. First I've increased "Frame per second" to 50 as this helps to make less flickering the lamp, though it requires more CPU resources. Then I changed some spice parameters to make simulation less accurate but faster; abstol=1e-08 and
PSS simulation is very tricky way to predict oscillation frequency. Transient is better with higher accuracy levels ( increase abstol,iabsoltol,vabstol in simulation option ). But PSS will also converged if you take care some critic nodes such as floating nodes, short circuited components etc. PSS doesn't like unusual circuit topologies and to avo
You can try to increase the value of abstol. For example: .options abstol=1E-8