AnsweredAssumed Answered

ADAU1442 Power

Question asked by rleopold on May 30, 2013
Latest reply on Jun 3, 2013 by rleopold

I'm confused on what "DVDD" needs to be to the ADAU1442.  The data sheet says 1.8 volts.  So on my layout I have it connected to +1.8 volts.  But then I was going to connect some pullups on the "PLLx" and "CLKMODEx" pins.  The data sheet shows these connected to DVDD but 1.8 volts does not meet Vin High Min for the digital I/O.  Then I looked at the EVAL board schematic and they have DVDD and PVDD (+3.3V) tied together.  Also I measured DVDD on the EVAL board and it measures 3.3 volts????  Is the data sheet wrong?

 

Message was edited by: Roger Leopold I see what's confusing me now.  On the Eval. Board (UG-032) there is a supply labeled "DVDD" but this does not power the "DVDD" pins (Figure 45, page 24).  I measured the power on the "DVDD" supply and it's 3.3 volts.  I measured the "DVDD" pins and they measure 1.8 volts. On the Data Sheet the supply connected to the "DVDD" pins is labeled "DVDD" (Figure 64, page 89). So a little confusing but I see that these pins should be +1.8 volts now. One other point.  On the Data Sheet the "Selfboot" pin is pulled up to "DVDD" - which is +1.8 volts here.  This would not meet Vin High Min..  On the Eval Board this signal is pulled up to +3.3 volts which seems correct.

Outcomes