NEC PD78052 User Manual page 268

(7) AV pin
REF0
This pin inputs the A/D converter reference voltage.
It converts signals input to ANI0 to ANI7 into digital signals according to the voltage applied between AV
and AV .
SS
The current flowing in the series resistor string can be reduced by setting the voltage to be input to the AV
pin to AV level in standby mode.
SS
Caution A serial resistor string of approximately 10 k is connected between the AV
AV pin. Therefore, when the output impedance of the reference voltage is high, it is
SS
connected in parallel to the serial resistor string between the AV
so that the reference voltage error increases.
(8) AV pin
SS
This is a GND potential pin of the A/D converter. Keep it at the same potential as the V
the A/D converter.
(9) AV pin
DD
This is an A/D converter analog power supply pin. Keep it at the same potential as the V
the A/D converter.
Caution AV pin is the power supply pin of the analog circuit, and it supplies power also to the input
DD
circuit of ANI0/P10 to ANI7/P17. Therefore, always supply the voltage of the same level as
V as shown in Figure 14-2 also in applications which switch to backup power supply.
DD
268
CHAPTER 14 A/D CONVERTER
Figure 14-2. Handling of AV
Main
Capacitor
power
supply for back-up
pin and the AV
REF0
pin when not using
SS
pin when not using
SS
Pin
DD
AV
REF0
V
DD
AV
DD
AV
SS
V
SS
REF0
REF0
pin and the
REF0
pin
SS