ICL-7107 Intersil, ICL-7107 Datasheet - Page 12

• Manufacturer Part Number: ICL-7107
• Description: 31/2 Digit/ LCD/LED Display/ A/D Converters
• Manufacturer: Intersil

Typical Applications
IN LO is tied to supply COMMON establishing the correct common mode
voltage. If COMMON is not shorted to GND, the input voltage may float
with respect to the power supply and COMMON acts as a pre-regulator
for the reference. If COMMON is shorted to GND, the input is single
ended (referred to supply GND) and the pre-regulator is overridden.
FIGURE 13. ICL7107 WITH AN EXTERNAL BAND-GAP
FIGURE 15. ICL7106 AND ICL7107: RECOMMENDED
COMMON
REF LO
COMMON
REF HI
OSC 1
OSC 2
OSC 3
IN LO
BUFF
BP/GND
TEST
C
C
REF LO
IN HI
GND
REF HI
REF
REF
A-Z
OSC 1
OSC 2
OSC 3
INT
REFERENCE (1.2V TYPE)
COMPONENT VALUES FOR 2V FULL SCALE
G2
G3
IN LO
BUFF
V -
C3
A3
TEST
C
C
IN HI
REF
REF
A-Z
INT
G2
G3
V -
C3
A3
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
TO DISPLAY
TO DISPLAY
0.47 F
0.22 F
100k
100pF
0.1 F
0.047 F
0.22 F
100k
100pF
47k
0.1 F
(Continued)
470k
TO PIN 1
ICL7106, ICL7107, ICL7106S, ICL7107S
1k
TO PIN 1
25k
0.01 F
SET V
= 100mV
10k
0.01 F
1M
1.2V (ICL8069)
SET V
= 100mV
24k
1M
REF
REF
10k
+
-
IN
V
+
-
-
V+
IN
V-
V +
12
Since low TC zeners have breakdown voltages ~ 6.8V, diode must
be placed across the total supply (10V). As in the case of Figure 14,
IN LO may be tied to either COMMON or GND.
An external reference must be used in this application, since the
voltage between V+ and V- is insufficient for correct operation of the
internal reference.
FIGURE 14. ICL7107 WITH ZENER DIODE REFERENCE
FIGURE 16. ICL7107 OPERATED FROM SINGLE +5V
COMMON
COMMON
REF LO
REF HI
OSC 1
OSC 2
OSC 3
REF LO
IN LO
BUFF
REF HI
TEST
C
C
IN HI
OSC 1
OSC 2
OSC 3
GND
IN LO
BUFF
TEST
C
C
REF
REF
A-Z
INT
IN HI
GND
G2
G3
V -
C3
A3
REF
REF
A-Z
INT
G2
G3
V -
C3
A3
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
TO DISPLAY
TO DISPLAY
0.47 F
100k
0.22 F
100pF
0.47 F
0.22 F
100k
0.1 F
100pF
47k
0.1 F
47k
TO PIN 1
1k
TO PIN 1
1k
0.01 F
SET V
= 100mV
10k
0.01 F
1M
1.2V (ICL8069)
SET V
= 100mV
100k
1M
REF
REF
15k
+
-
IN
+
-
6.8V
+5V
IN
-5V
+5V