Daisy chaining AD5271 and ADG714 possibility

Document created by analog-archivist Employee on Feb 23, 2016
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For SPI, Is it possible to daisy chain 8 x ADG714BRU potimeters together with
the
ADG714. As the ADG714 is 8 bits and the AD5271 is 16 bit

 

It appears possible, but one must exercises care e.g. such as
below (please note: presented below are only are a few examples but one need to
be vigilante, sync and aligned everything) from timing to data packets to i/o
voltage levels supply levels etc.

exercise care for multi mixed IC daisy-chaining examples parameters
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(1) use the slowest clock of the two.
(2) try and group similar parts together at either at front or back and try not
mixing the sequence. Which can be out of sync due to timing and data alignment
(3) As the AD5270 is 16 bit data which the ADG714 are 8 bit data.  You need to
aligned and sequence data daisy chain length carefully and accordingly e.g. 
Since the requirement for the The AD5270/AD5271 have an internal counter that
counts a multiple of 16 bits (a frame) for proper operation. For example,
AD5270/AD5271 each works with a 32-bit word but do not work properly with a
31-bit or 33-bit word.

(4) check and use worst case timing setup and hold times.
(5) check and use same voltage level.

As you can see there are a lot of careful analysis to be done for operation to
work in sync. for mixing IC for daisy chaining.
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