TC7126 TelCom, TC7126 Datasheet - Page 4

• Manufacturer Part Number: TC7126
• Description: 3-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTERS
• Manufacturer: TelCom

3-220
TC7126
TC7126A
PIN DESCRIPTION
40-Pin PDIP
Pin Number
Normal
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
1
2
3
4
5
6
7
8
9
(Reverse)
(40)
(39)
(38)
(37)
(36)
(35)
(34)
(33)
(32)
(31)
(30)
(29)
(28)
(27)
(26)
(25)
(24)
(23)
(22)
(21)
(20)
(19)
(18)
(17)
(16)
(15)
(14)
(13)
(12)
(11)
(10)
(9)
(8)
COMMON
ANALOG
Name
V
POL
C
V
V
V
AB
C
BP
BUFF
D
C
G
D
C
D
G
C
G
V
B
A
F
E
B
A
F
E
B
F
E
A
V
REF
INT
IN
IN
AZ
+
1
1
1
1
2
2
2
2
3
3
3
3
–
1
1
1
2
2
3
3
3
2
4
–
+
–
Description
Positive supply voltage.
Activates the D section of the units display.
Activates the C section of the units display.
Activates the B section of the units display.
Activates the A section of the units display.
Activates the F section of the units display.
Activates the G section of the units display.
Activates the E section of the units display.
Activates the D section of the tens display.
Activates the C section of the tens display.
Activates the B section of the tens display.
Activates the A section of the tens display.
Activates the F section of the tens display.
Activates the E section of the tens display.
Activates the D section of the hundreds display.
Activates the B section of the hundreds display.
Activates the F section of the hundreds display.
Activates the E section of the hundreds display.
Activates both halves of the 1 in the thousands display.
Activates the negative polarity display.
Backplane drive output.
Activates the G section of the hundreds display.
Activates the A section of the hundreds display.
Activates the C section of the hundreds display.
Activates the G section of the tens display.
Negative power supply voltage.
The integrating capacitor should be selected to give the maximum voltage swing
that ensures component tolerance build-up will not allow the integrator output to
saturate. When analog common is used as a reference and the conversion rate is
3 readings per second, a 0.047 F capacitor may be used. The capacitor must
have a low dielectric constant to prevent roll-over errors. See "Integrating Capaci-
tor" section for additional details.
Integration resistor connection. Use a 180 k resistor for a 200 mV full-scale
range and a 1.8 M resistor for a 2V full-scale range.
The size of the auto-zero capacitor influences system noise. Use a 0.33 F
capacitor for 200 mV full scale, and a 0.033 F capacitor for 2V full scale. See
paragraph on auto-zero capacitor for more details.
The low input signal is connected to this pin.
The high input signal is connected to this pin.
This pin is primarily used to set the analog common-mode voltage for battery
operation or in systems where the input signal is referenced to the power supply.
See paragraph on analog common for more details. It also acts as a reference
voltage source.
See pin 34.
ANALOG-TO-DIGITAL CONVERTERS
TELCOM SEMICONDUCTOR, INC.
3-1/2 DIGIT