ICL7129 Intersil, ICL7129 Datasheet - Page 4

• Manufacturer Part Number: ICL7129
• Description: 41/2 Digit LCD/ Single-Chip A/D Converter
• Manufacturer: Intersil

Pin Descriptions
PIN
10
11
12
13
14
15
16
17
18
19
20
21
22
1
2
3
4
5
6
7
8
9
B
ANNUNCIATOR
B
B
2
LATCH/HOLD
3
B
F
, C
F
F
F
1
A
A
A
A
, C
SYMBOL
1
2
3
4
4
, C
DP
DP
1
2
3
4
DRIVE
, E
, E
, E
, C
, E
2
OSC
OSC
V
, G
, G
, G
, D
3
BP
BP
BP
, LO BATT Output to display segments.
1
DlSP
4
3
1
2
, MINUS
3
4
4
, CONT
4
/OR
1
2
3
/UR
, DP
, DP
, DP
, DP
, BC
3
2
1
, G
, D
, D
, D
1
3
1
2
3
4
1
2
3
4
5
Input to first clock inverter.
Output of second clock inverter.
Backplane squarewave output for
driving annunciators.
Output to display segments.
Output to display segments.
Output to display segments.
Output to display segments.
Output to display segments.
Output to display segments.
Output to display segments.
Output to display segments.
Output to display segments.
Output to display segments.
Output to display segments.
Backplane #3 output to display.
Backplane #2 output to display.
Backplane #1 output to display.
Negative rail for display drivers.
INPUT: When HI, turns on most
significant decimal point.
OUTPUT: Pulled HI when result
count exceeds 19,999.
INPUT: Second most significant
decimal point on when HI.
OUTPUT: Pulled HI when result
count is less than 1,000.
INPUT: When floating, A/D converter
operates in the free-run mode. When
pulled HI, the last displayed reading is
held. When pulled LO, the result
counter
incrementing during the de-integrate
phase of cycle.
OUTPUT: Negative going edge
occurs when the data latches are
updated. Can be used for converter
status signal.
DESCRIPTION
contents
are
shown
ICL7129
3-34
PIN
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
CONTINUITY
COMMON
SYMBOL
INT OUT
BUFFER
REF LO
RANGE
REF HI
C
DGND
INT IN
C
IN LO
OSC2
IN HI
DP
DP
REF
REF
V+
V-
2
1
+
-
Negative power supply terminal.
Positive power supply terminal, and
positive rail for display drivers.
Input to integrator amplifier.
Output of integrator amplifier.
INPUT: When LO, continuity flag on
the
continuity flag is on.
OUTPUT: HI when voltage between
inputs is less than +200mV. LO
when voltage between inputs is
more than +200mV.
Sets common-mode voltage of 3.2V
below V+ for DE, 10X, etc., Can be
used as pre-regulator for external
reference.
Positive side of external reference
capacitor.
Negative side of external reference
capacitor.
Output of buffer amplifier.
Negative input voltage terminal.
Positive input voltage terminal.
Positive reference voltage input
terminal.
Negative reference voltage input
terminal.
Ground reference for digital section.
3 A pull-down for 200mV scale.
Pulled HIGH externally for 2V scale.
Internal 3 A pull-down. When HI,
decimal point 2 will be on.
Internal 3 A pull-down. When HI,
decimal point 1 will be on.
Output of first clock inverter. Input of
second clock inverter.
display
DESCRIPTION
is
off.
When
HI,