NEC UPD789426 Series User Manual page 200

CHAPTER 10 8-BIT A/D CONVERTER (
Figure 10-11. A/D Conversion End Interrupt Request Generation Timing
Rewriting to ADM0
(to begin conversion
for ANIn)
A/D conversion
ADCR0
INTAD0
Remarks 1. n = 0 to 5
2. m = 0 to 5
(9) AV pin
DD
The AV pin is used to supply power to the analog circuit. It is also used to supply power to the ANI0 to
DD
ANI5 input circuit.
If your application is designed to be changed to backup power, the AV
voltage level as the V
(10) AV pin input impedance
DD
A series resistor string of several ten of kΩ is connected between the AV
the output impedance of the reference voltage supply is high, the reference voltage supply will form a parallel
connection with the series resistor string, creating a large reference voltage differential.
200
Rewriting to ADM0
(to begin conversion
for ANIm)
ANIn ANIn
ANIn
pin, as shown in Figure 10-12.
DD
Figure 10-12. AV
Main power
source
User's Manual U15075EJ2V1UD
µ
PD789426 AND 789446 SUBSERIES)
ADIF0 has been set, but conversion
for ANIm has not been completed.
ANIm
ANIn
pin must be supplied with the same
DD
Pin Handling
DD
V
DD
AV
DD
Backup
capacitor
V
SS
AV
SS
and AV
DD
ANIm
ANIm ANIm
pins. Consequently, if
SS