2008/12/24, Sebastien Lelong <[email protected]>: > Just to be sure: sample/secs is more important than MHz, right ? PDS5022S > runs @25MHz for 100MS/s, whereas the one you point to runs @60MHz, for > 100MS/s too. How is it possible ? Is there something with the number of > channels: 25MHZ and 100MS/s for one channel, far less with 2 channels at the > same time, and 60MHz and 100MS/s for each channel ?
The 60 MHz is the actuall bandwith of the input circuit. This means that a 60 MHz sine is reduced by 50% (-3dB) before it reaches the A/D converter. And since Shannon learned us that you need at least to sample 2x the max frequency, this is well within range. The Owen specs are not that simple. The 25 MHz is simulated bandwith for repeated signals according to their documentation. For single shots, 'max bandwidth' is available. So the input circuit probably has a bandwidth of at least 50MHz. But on a repetitive signal, the software reduces the bandwith to 25Mhz. I think this is to avoid showing strange spikes as a result of signals close to half the sampling rate. Joep --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/jallib?hl=en -~----------~----~----~----~------~----~------~--~---
