Sample time setting for high frequency systems

What sample time should I use when simulating a system operating at 100 kHz?

It seems to me that the typical 0.2 seconds would be to small.

Are there quidelines for determining the appropriate sample time?

Answer 1

[Fangjun Jiang]

A 100kHz signal means its period is 10us. If the signal is a sine wave, you would need about 20 data points to represent a complete cycle of a sine wave with good quality. That means 0.5us is your maximum step size or sample time. 0.2 seconds is way bigger.

Answer 2

[Stephen]

Thanks,

Should the sample time for all elements in the system be set to the 0.5 usec (the number in the above post) or just those that are actually operating at that frequency (100 kHz). Can other elements be set to a slower data rate?

[Fangjun Jiang]

Sure. The proper sample time should be determined by the need of the application. To measure the noise level and temperature of a living room, for example, could have quite different sample time.