Gear vs Trap, what are those and how to optimize?

QSPICE
1

Whats the actual difference between Gear and Trap?
I have found SPICE Differentiation | Analog Devices
The only thing I understand is, Gear can artificially dampen all oscillation (which, I think for SMPS circuit is generally not an issue).

and what is the general rule of thumb to tune the simulation speed (for SMPS application).

Another thing is I found someone saying that trap is generally faster than gear. However, my simulation (digital smps with c-block for all control) find that simulation with gear can be completed in 30% less time than trap for virtually no difference.

Thanks for kind explanation.

*happy new year
Arief,

2

Aside from a few exceptions, Gear is both slower and less accurate than trap. The main problem with trap is a ringing artifact that bothers people, even though the area under each trapezoid is correct.

You’ve discovered the main point to offering both in the same simulator: if you get the same answer using both methods, you know that the solution is not affected by integration artifacts.

–Mike

3

Hi Mike,

I have no issue with my result… I am only looking to improve the speed as well as to get deeper understanding on the integration method. However, I get confused, as in my case the Gear method is quite a bit faster than Trap…