Re: Digital O'scopes: Sampling Rate vs. Sample Storage Space

On Aug 16, 7:28 am, soda...@xxxxxxxxx wrote:
What is the relative importance of sampling rate versus sample memory
in a digital oscilloscope?

I'm looking at two candidates: one has a sampling rate of 2GS/sec, but
only 2.5K of sample memory, while the other samples at only 400MS/sec,
but has 1M of sample memory.

For debugging microcontroller systems with typical peripherals (I2C,
SPI, ADC, LCD), which is more important, sampling rate or sample
memory size?

By FAR the best option in this case is the 1M of sample memory.
2.5KB is not much use at all in analysing serial data packets.
1MB will allow you to capture and post analyse long and/or widely
dispersed packets in the one capture.
In this case 400MS/s will be more than enough sample rate for say
50MHz clock rate systems (analog bandwidth dependent of course).

You'll never ever regret getting a digital scope with a large sample
memory, but you'll often regret one that only has 2.5KB.

One could of course argue that a logic analyser might be more useful
here as an additional tool, but that's another ball game.

A mixed signal scope (analog + logic analyser) is also a superb
option. Rigol make some good low cost ones.

Dave.
.

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