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HARDWARE
4507 Group User’s Manual
FUNCTION BLOCK OPERATIONS
A-D CONVERTER
The 4507 Group has a built-in A-D conversion circuit that performs
conversion by 10-bit successive comparison method. Table 11
shows the characteristics of this A-D converter. This A-D converter
can also be used as an 8-bit comparator to compare analog volt-
ages input from the analog input pin with preset values.
Table 11 A-D converter characteristics
Characteristics
Successive comparison method
10 bits
Linearity error: ±2LSB
Non-linearity error: ±0.9LSB
46.5
s (High-speed mode at 4.0 MHz
oscillation frequency)
4
Parameter
Conversion format
Resolution
Relative accuracy
Conversion speed
Analog input pin
Fig. 27 A-D conversion circuit structure
VSS
VDD
DAC
DA converter
TABAD
1/6
Q13
Q11 Q10
Q12
TADAB
0
1
4
8
01
1
8
10
Q13
0
1
Q13
8
(Note 1)
8
2
TALA
Q13
TAQ1
TQ1A
ADF
(1)
P20/AIN0
2
1
0
10
P21/AIN1
P30/AIN2
P31/AIN3
IAP3
(P30, P31)
OP3A
(P30, P31)
IAP2
(P20, P21)
OP2A
(P20, P21)
Register A (4)
Register B (4)
DAC
operation
signal
Comparator
4-
c
h
a
n
el
m
u
lt
i-
p
le
x
e
d
an
a
lo
g
s
w
it
c
h
Instruction clock
A-D control circuit
Successive comparison
register (AD) (10)
A-D
interrupt
Comparator register (8)
Notes 1: This switch is turned ON only when A-D converter is operating and generates the comparison voltage.
2: Writing/reading data to the comparator register is possible only in the comparator mode (Q13=1).
The value of the comparator register is retained even when the mode is switched to the A-D conversion
mode (Q13=0) because it is separated from the successive comparison register (AD). Also, the resolution
in the comparator mode is 8 bits because the comparator register consists of 8 bits.
(Note 2)