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ADAR7251 Initialization

Question asked by zek on Jan 22, 2016
Latest reply on Feb 27, 2017 by Rajeev



I have just started working with the ADAR7251.  I've been having trouble properly programming it over SPI.


The first configuration I want to program is as simple possible for ADC Channels 1 and 2 at 1.2 MSps, with no LNA, PGA, EQ, or HPF on either channel.  I have a 20 MHz input clock so I set X = 1, M = 1000, N = 760 and R = 5.  I would like to output the data using the PPI byte wide configuration.


I have a few questions about the process.  In what order should I program the registers?  For example, register 0x040 is Master_Enable.  Does this enable the entire chip except for the SPI?  Do I need to program this register before all others?  The next logical register to program for me is 0x042 Power_Enable.  Will the PLL and other sections work properly if I don't program this register before I program the others?  Are there others that I am missing?


I have attached a config spreadsheet for how I am currently programming all of the chip registers for your reference.


It would be great to see how the Eval Software does this as well so I can just copy the same order.



Zach Kabelac