4507 Datasheet, PDF (31/115 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4507 Group
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
Parameter
Characteristics
Conversion format Successive comparison method
Resolution
10 bits
Relative accuracy Linearity error: ±2LSB
Differential non-linearity error: ±0.9LSB
Conversion speed 46.5 µs (High-speed mode at 4.0 MHz
oscillation frequency)
Analog input pin
4
Register B (4)
IAP2
(P20, P21)
OP2A
(P20, P21)
P20/AIN0
P21/AIN1
P30/AIN2
P31/AIN3
IAP3
(P30, P31)
OP3A
(P30, P31)
2
Register A (4)
TAQ1
TQ1A
Q13 Q12 Q11 Q10
Instruction clock
1/6
44
44
2
TALA
8
TABAD
8
TADAB
A/D control circuit
Q13
0
1
ADF
(1)
Comparator
1
0
Q13
Successive comparison
register (AD) (10)
10
10
DAC
operation
signal
01
Q13
A/D
interrupt
Q13
8
01
1
(Note 1)
VSS
DAC
DA converter
Comparator register (8)
(Note 2)
8
VDD
88
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.
Fig. 28 A/D conversion circuit structure
Rev.3.01 2005.02.04 page 31 of 111
REJ03B0107-0301