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ADAU1466 operating current and clock speed variation

Question asked by archerator on Nov 5, 2017
Latest reply on Nov 8, 2017 by archerator

Hello, and thanks in advance to the AD engineers who hopefully look at this!


I would like to use the ADAU1466 in an upcoming design, but have a question about power consumption since my application is battery powered.  On page 5 of the datasheet, under "Digital Current (DVDD)" and "Maximum Program", there is a typical value 233mA and a max value of 495mA.  This is a bit confusing since the next line is the spec for "Typical Program", which is given as 220mA.  I would assume that the 233-495mA range is across the full operating temperature range, but a temperature condition of Ta=25C is given at the top of the page. 


My question is, with a max program load, what changing conditions cause the current to range from 233-495mA?  Is it temperature like I am guessing, and if so, is there a graph of max current vs Ta that I can see?


A related question would be the following... I assume the above current spec is for a core clock of 294.912 MHz.  Is it possible to run the core (or any of the 146x series) at half that rate to save power?  It's awesome that it can run that fast but half of that will probably be sufficient for my needs.  On page 9 fclock is given a min of 152 MHz, but the PLL settings examples on page 29/30 don't show any typical uses of frequencies that low, which makes me a bit suspicious.


I would like to stay with the 1466 since it's got so much more RAM, which I will probably need, but if I have to go to the 1462 or 1463 to save power by cutting the core clock I might.  Of course, if I can guarantee that the max current will stay in the bottom part of that 233-495mA range this doesn't matter.  Any input on this would be appreciated!


I have a few other questions but I'll restrain for now since the above are the most important...