NEC mPD780065 Series Preliminary User's Manual page 175

(6) ANI0 to ANI7 pins
These are eight analog input pins to input analog signals to undergo A/D conversion to the A/D converter. ANI0
to ANI7 are alternate-function pins that can also be used for digital input.
Cautions 1. Use ANI0 to ANI7 input voltages within the specification range. If a voltage higher than
AV or lower than AV
REF
conversion value of that channel will be undefined and the conversion values of other
channels may also be affected.
2. When a digital pulse is applied to a pin adjacent to the pin in the process of A/D conversion,
A/D conversion values may not be obtained as expected due to coupling noise. Thus, do
not apply any pulse to a pin adjacent to the pin in the process of A/D conversion.
(7) AV pin
REF
This pin inputs the A/D converter reference voltage. It can also be used as analog power supply.
It converts signals input to ANI0 to ANI7 into digital signals according to the voltage applied between AV
AV .
SS
Caution A series resistor string of approx. 10 kΩ is connected between the AV
Therefore, when the output impedance of the reference voltage is too high, it seems as if the
AV pin and the series resistor string are connected in parallel. This may cause a greater
REF
reference voltage error.
(8) AV pin
SS
This is the GND potential pin of the A/D converter. Always keep it at the same potential as the V
when not using the A/D converter.
CHAPTER 11 A/D CONVERTER
is applied (even if within the absolute maximum rating range), the
SS
Preliminary User's Manual U13420EJ2V0UM00
and
REF
pin and AV pin.
REF SS
pin even
SS0
175