Which accuracy should I use? (Spectre Simulation)

[hspice]

I’m simulating a Sampling and Hold circuit, which has 14 bit resolution. The simulator is spectre. When I set ‘accuracy (errpreset)’ to ‘moderate’, the result (after DFT of transient simulation results) shows about 12 bit resolution. However, after setting ‘conservative’, it has about 14 bit performance. My question is, which result is more reliable?

Also, with switched capacitor circuit, like this S/H, which integer method is better? Trap, Trapgear2 or Gear2?

Thanks a lot.

 

[dwang_w]

the concerve is relilable

i have desiged a S/H, but

i can,t understand the integer gear ,can you explain detail?

 

[alastair41]

GEAR is a numerical method in computing an integral. Cadence provides different numerical integral solver for different application. For example, if you have a convergence problem with one method, say trapozoidal, you may try gear2.

 

[santhoshv78]

whenever i need accurate results, i simulate with conservative and gear method.