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AVCC & VCC should not be different

Started by Matthias Weingart August 1, 2004
Hi,
after some tests with a '149 I can tell you that 
 AVCC >= VCC-0.3V 
 A unconnected AVCC-pin already has a voltage of 3.28V (with 3.6VCC, ADC
and VREF sometimes enabled). I tried a 3V regulator (79730) and I got
2.97volts, after connecting AVCC I got 3.05volts and the current consumption
increases (the current looks very ugly in the osci, the current spikes of
the ADC grows in time).
However using a 3.3V regulator it works as expected.

        Matthias

Beginning Microcontrollers with the MSP430