Page 235 - DCAP108_DIGITAL_CIRCUITS_AND_LOGIC_DESIGNS

Digital Circuits and Logic Design

Notes signal to a digital signal having 3 bits; it is necessary to have seven comparators (this allows a
division of the input into eight ranges).

Figure 12.20: 2-Bit Simultaneous A/D Converter

Figure 12.21: 3-bit Simultaneous A/D Converter—(a) Logic Diagram,
(b) Using a 9318 Priority Encoder

READ RESET
Analog input voltage line line
2
2
C 7 S Q
+7V/8 C C R Q
6
6
+3V/4 C
5
+5V/8 2 1
C 4 C 4 S Q
+V/2 C 3 R Q Digital
output
+3V/8 C 2 C 2
+V/4 C 1

+V/8 0
2
Comparators S Q
READ
gates R Q
Encoding metrix
Output register
()
a
Analog input voltage
C 7
7V/8
C
6
3V/4
C 5
5V/8 A 2 2
2
C A 1 Digital
4 1 2
V/2 9318 outputs
A 0
C 3 0 2
3V/8
C 2
V/4
C
1
V/8
()
b

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