AD9640: Maximum and minimum aperture delay

Document created by analog-archivist Employee on Feb 23, 2016
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Regarding the Timing Characteristics of the 9640D device, do you have more
detailed data for the - APERTURE DELAY: i.e. MIN and MAX values, around the
1.0ns typ stated on the datasheet - APERTURE DELAY VARIATION: i.e. between two
channels of the same device (no info on the datasheet)

 

Unfortunately, we only have typical data on this specification. However, the
quality of the Clock will determine the maximum value of the aperture jitter
that may occur. This in turn will directly affect your max aperture delay and
SNR value. So, I can only recommend you use a good quality Clock with this
device.

From pervious comment by the AD9640 engineer on aperture delay variation:

In the design of the AD9640 (and all our dual converters) we try to match the
clock delays between channels as closely as possible.  These delays are also
designed to track between channels over temperature.  We expect the AD9640
sampling edge mismatch between the two channels to be in the 100ps range,
however this is not something that we typically characterize or guarantee.
In most receiver systems that I am aware of the phase errors caused by the
mismatch of the ADC aperture delays is quite small relative to phase errors
introduced elsewhere in the receive circuit (from the demod, drive amps, or
filter circuits).

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