UPD75064 Datasheet, PDF (25/68 Pages) NEC – 4-BIT SINGLE-CHIP MICROCOMPUTER

µPD75064, 75066, 75068, 75064(A), 75066(A), 75068(A)
5.8 A/D Converter
The µPD75068 contains an 8-bit analog/digital (A / D) converter that has eight analog input channels
(AN0 - AN7).
The A /D converter employs the successive-approximation method.
Figure 5-7. Block Diagram of A/D Converter
Internal bus
8
0 ADM6 ADM5 ADM4 SOC EOC ADM1 0 ADM
8
AN0/P110
AN1/P111
AN2/P112
AN3/P113
AN4/KR0/P60
AN5/KR1/P61
AN6/KR2/P62
AN7/KR3/P63
Sample and hold circuit
Multi-
plexer
Control circuit
+
–
Comparator
Tap decoder
SA register (8)
8
AVREF
AVSS
R/2
R
R
R R/2
Series resistor string
25