![](http://datasheet.mmic.net.cn/140000/TC7129CPL_datasheet_5017043/TC7129CPL_4.png)
4
TC7129
4-1/2 DIGIT ANALOG-TO-DIGITAL
CONVERTER WITH ON-CHIP LCD DRIVERS
PIN DESCRIPTIONS
Pin No.
40-Pin
44-Pin
TC7129CPL
TC7129CKW
TC7129CLW
Symbol
Function
1
40
2
OSC1
Input to first clock inverter.
2
41
3
OSC3
Output of second clock inverter.
3
ANNUNCIATOR
Backplane square-wave output for driving annunciators.
443
5
B1, C1, CONT
Output to display segments.
544
6
A1, G1, D1
Output to display segments.
61
7
F1, E1, DP1
Output to display segments.
72
8
B2, C2, LO BATT
Output to display segments.
83
9
A2, G2, D2
Output to display segments.
94
10
F2, E2, DP2
Output to display segments.
10
5
11
B3, C3, MINUS
Output to display segments.
11
7
13
A3, G3, D3
Output to display segments.
12
8
14
F3, E3, DP3
Output to display segments.
13
9
15
B4, C4, BC5
Output to display segments.
14
10
16
A4, D4, G4
Output to display segments.
15
11
17
F4, E4, DP4
Output to display segments.
16
12
18
BP3
Backplane #3 output to display.
17
13
19
BP2
Backplane #2 output to display.
18
14
20
BP1
Backplane #1 output to display.
19
15
21
VDISP
Negative rail for display drivers.
20
16
22
DP4/OR
Input: When HI, turns on most significant decimal point.
Output: Pulled HI when result count exceeds
±19,999.
21
18
24
DP3/UR
Input: Second most significant decimal point on when HI.
Output: Pulled HI when result count is less than
±1000.
22
19
25
LATCH/HOLD
Input: When floating, ADC operates in the free-run mode.
When pulled HI, the last displayed reading is held. When
pulled LO, the result counter contents are shown
incrementing during the deintegrate phase of cycle.
Output: Negative-going edge occurs when the data
latches are updated. Can be used for converter status
signal.
23
20
26
V–
Negative power supply terminal.
24
27
V+
Positive power supply terminal and positive rail for display
drivers.
25
21
28
INT IN
Input to integrator amplifier.
26
23
29
INT OUT
Output of integrator amplifier.
27
24
30
CONTINUITY
Input: When LO, continuity flag on the display is OFF.
When HI, continuity flag is ON.
Output: HI when voltage between inputs is less than +200
mV. LO when voltage between inputs is more than +200
mV.
28
25
31
COMMON
Sets common-mode voltage of 3.2V below V+ for DE,
10X, etc. Can be used as preregulator for external
reference.
29
26
32
C
+
REF
Positive side of external reference capacitor.
30
27
33
C
-
REF
Negative side of external reference capacitor.
31
29
35
BUFFER
Output of buffer amplifier.
32
30
36
IN LO
Negative input voltage terminal.
33
31
37
IN HI
Positive input voltage terminal.