Can the AVref pin on the SH7045 be supplied at 2.5V with Avcc=Vcc=5V ?
The voltage on the Avref and Avcc pins should be equal to Vcc. The reason why Avref and Avcc are separate from the digital supply is to support better accuracy of the A/D. Applying a voltage less than Vcc to Avref or Avcc may cause excessive leakage currents to occur and is out of spec. Avcc is the digital supply to the A/D converter and Avref is the voltage applied to the top of the R-2R ladder in the A/D. On 112 pin versions these two pins are tied together internally. Avref and Avcc should be connected to Vcc when the A/D converter is not being used