Completed Project Simulating a Buck converter on LTspice [SOLVED]

Thread Starter

anishkgt

Joined Mar 21, 2017
529
Hey All,

I am trying to simulate the schematic of a ADP1850 buck converter on page 30 in its datasheet. Normally i set the transient time to 1second and see if i get the desired voltage and move on from there. Simulating this specific one takes more than a minute to complete so cancelled it. Is it normal ? should the transient be lower like 1ms or something. I checked at 1ms and it does not seem to match the voltage in the schematic. The vout is set to 1.09V but the simulation seems to be overshooting it.
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Veracohr

Joined Jan 3, 2011
724
I don’t know about that specific model but I’ve been simulating a SEPIC converter with a different model and it takes several minutes on a decently powerful computer to reach ~100ms of simulated time. The simulation time will depend on the complexity of the model and the switching frequency.
 

Thread Starter

anishkgt

Joined Mar 21, 2017
529
Thanks i've breaking my head thinking it was something to do with the schematic, been going back and forth from datasheet to simulation. To keep things in perspective this one took 5 seconds to simulate 500uS on an i7 9th Gen.

Any idea how this IC can be paralleled for higher current ?
 

ronsimpson

Joined Oct 7, 2019
910
It takes millions of cycles of a pwm to get up and running. (maybe 100s of thousands) You can start out with the output voltage at 4V and watch it clime to 5.0V to save time and CPU power. Use .IC command. Initial condition.
 
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