3-1/2 DIGIT A/D CONVERTERS
1
2
3
4
5
6
7
8
TC14433
TC14433A
470k
0.1µF 0.1µF
RESISTOR
NETWORK
OR
R /C
C C0
C0
1 1
R
1
1
1
2
+5V
V
X
V
CLK1
CLK0
OR
X
300k
INPUT
V
AG
INDIVIDUAL
RESISTOR*
DU
27kΩ
R
B1
a
Q
0
A
B
C
EOC
Q
b
c
d
e
1
TC14433
TC04
V
REF
Q
2
100kΩ
D I4511B
LT
V
SS
+5V
f
LE
V
g
V
DD
V
SS
DD
V
EE
R
DP
DS
4
DS DS
2 1
DS
3
R
M
For V
REF
= 2000V
V : 1.999V full scale
COMMON
CATHODE
LED DISPLAY
V
EE**
(MINUS)
+5V
For V = 200 mV
REF
V : 199.9 mV full scale
(change 470k to R = 27k
and decimal point position)
MINUS
CONTROL
Peak digit current for an eight
displayed is 7 times the segment
current.
75492
OR
1413*
*To increase segment current
capability add two 75491 ICs
between 14511B and Resistor
Network. The use of the 1413
as digit driver increases digit
current capability over the 75492.
DIGIT DRIVERS
ALTERNATE OVERRANGE CIRCUIT
WITH SEPARATED LED
R
1/6
R
75492
OR
1/7 1413
**V can range between –2.8 and
–11V.
OR
+5V
Figure 14. 3-1/2 Digit Voltmeter with Low Component Count Using Common Cathode Displays
TELCOM SEMICONDUCTOR, INC.
3-135
TELCOM [ TELCOM SEMICONDUCTOR, INC ]
