Autonerdz forums

Rudy,

You have to sample at least twice the frequency of a signal just to avoid aliasing.  For best digital reconstruction you need to sample 5 to 10 times signal frequency.

The 4000 series scopes were made to tackle Flex Ray communication, which can be 10MHz.  So, now the dual 80MHz ADCs in the 4000 series scopes can sample that at 8x.

Of course, real time sample rate is a function of ADC speed, record length, and capture time.  So, a large memory depth is needed to be able to maintain robust sample rates at long enough time bases to capture enough signal to analyze.

The 4000 scopes have you covered there also with the internal 32 million point sample memory.

I also assumed the question related to sample rate, although it was not clear.  Maximum samples per second = 80,000,000.

I later saw this was a question that was also asked on the iATN Technical Theory Forum.  A lot of misinformation was provided there including much confusion between sample rate and bandwidth.  They are two completely different things.

The 4423 has a 20MHz bandwidth.  This means that it will not begin attenuating (distorting) the signal until you approach 20MHz.  In other words, the maximum frequency of signal that can pass through the front-end amplifiers.

This all takes place before the signal is even sampled.

As mentioned earlier, you must sample at least 2x signal frequency to avoid aliasing.  So, you would need a minimum sample rate of 40MHz to even come close to making use of the 20MHz bandwidth before the signal became useless.  The Pico 4423 has enough sample rate power to sample at up to 4x the bandwidth.