tc7136a Microchip Technology Inc., tc7136a Datasheet - Page 7

• Manufacturer Part Number: tc7136a
• Description: Low Power 3-1/2 Digit Analog-to-digital Converter
• Manufacturer: Microchip Technology Inc.

2.0
The descriptions of the pins are listed in Table 2-1.

TABLE 2-1:
2002 Microchip Technology Inc.
(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
PIN DESCRIPTIONS
PIN DESCRIPTION
(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)
(10)
(11)
(9)
(8)
COMMON
ANALOG
Symbol
V
C
V
POL
V
AB
C
V
BUFF
V+
BP
D
C
G
D
C
D
G
C
G
REF
B
A
F
E
B
A
F
E
B
F
E
A
V-
IN
INT
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 buildup will not allow the integrator output to sat-
urate. When analog common is used as a reference and the conversion rate is 3
readings per second, a 0.047µF capacitor may be used. The capacitor must have a
low dielectric constant to prevent rollover errors. See Section 6.3, Integrating
Capacitor for additional details.
Integration resistor connection. Use a 180kΩ for a 20mV full scale range and a
1.8MΩ for 2V full scale range.
The size of the auto-zero capacitor influences the system noise. Use a 0.47µF
capacitor for a 200mV full scale and a 0.1µF capacitor for a 2V full scale.
See Section 6.1, 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 Section 7.3, Analog Common for more details. It also acts as a reference
voltage source.
See Pin 34.
TC7136/TC7136A
DS21461B-page 7