514
Digital Electronics
8-Bit
Latch
4 3 2 1 17 16 14 13
-V GG
Selection
And
Control
Logic
Analog
Switches
P-Resistor
N-Body
450
300
150
300
256R
Network
Comparator
12
5
MSB
LSB
Complementary
Digital Output
Analog
Input
R-Network
Bottom
V in
R-Network
Top
15
10
(PMOS
Body)
V SS
6
Clock
11
Start
Conversion
9
End of
Conversion
(EOC)
8
7 Tristate
Output
Enable
18
V DD
Digital
Ground
Figure 12.41 Internal architecture of AD 0800.
Figures 12.42(a) and (b) show application circuits using AD-0800. Figure 12.42(a) shows typical
circuit connections for a ±5 V input voltage range and TTL-compatible output levels, whereas
Fig. 12.42(b) shows the connections for a 0–10 V input range and 0–10 V output levels.
12.12.2 ADC-0808
ADC 0808 is an eight-bit CMOS successive approximation type A/D converter. The device has
an eight-channel multiplexer and a microprocessor-compatible control logic. Salient features of
the device include eight-bit resolution, no missing codes, a conversion time of 100 s (typical),