LTspice sim is very slow

[Flyback]

Hi,
Do you have any way to speed up this LTspice sim?

 

[Papabravo]

Why would you expect such a simulation with that sort of encrypted part to run fast?

 

[crutschow]

How slow is "slow"?

 

[eTech]

You haven't provided any design parameters.
But the switching frequency is set to ~450kHz, so the sim will be slower than the example circuit operating at 250kHz.

In addition, don't use "uic" in the .trans statement. Use "startup".

 

[aliarifat794]

Not much details... By the way, here is a thread about speeding up LTspice simulation. You can check the answers. https://www.electro-tech-online.com/threads/speed-up-simulation-with-ltspice.119273/

 

[simonbramble]

Remove the series resistance in both of the power supplies. Remove the gate resistors - this is just bad design practice and will also slow down your simulation time. Use a resistor in series with the BOOST pin (between the flying cap and the BOOST pin) for a more effective solution. Remove the resistors between the cathodes of the BST Schottky diodes and the flying capacitors. This has speeded up my simulation, but it will still run slow as it transitions from boost to buck mode - Simon

 

[simonbramble]

the control loop also needs stabilising. Not sure if your current sense resistor is too small. if it is, this will create loop instability problems because the triangular waveform across the sense resistor feeds into the control loop (since it is current mode control), so you may have to increase this. I have not done the design calcs, so this is only a guess