
3-113
TELCOM SEMICONDUCTOR, INC.
7
6
5
4
3
1
2
8
GENERAL DESCRIPTION
The TC7135 4-1/2 digit analog-to-digital converter (ADC)
offers 50 ppm (1 part in 20,000) resolution with a maximum
nonlinearity error of 1 count. An auto-zero cycle reduces zero
error to below 10
μ
V and zero drift to 0.5
μ
V/
°
C. Source
impedance errors are minimized by a 10 pA maximum input
current. Roll-over error is limited to
±
1 count.
By combining the TC7135 with a TC7211A (LCD) or
TC7212A (LED) driver, a 4-1/2 digit display DVM or DPM can
be constructed. Overrange and underrange signals support
automatic range switching and special display blanking/flash-
ing applications.
Microprocessor-based measurement systems are sup-
ported by BUSY, STROBE, and RUN/HOLD control signals.
Remote data acquisition systems with data transfer via UARTs
are also possible. The additional control pins and multiplexed
BCD outputs make the TC7135 the ideal converter for dis-
play or microprocessor-based measurement systems.
TC7135
ORDERING INFORMATION
Temperature
Range
Part No.
Package
TC7135CBU
64-Pin Plastic
Flat Package
28-Pin PLCC
0
°
C to +70
°
C
TC7135CLI
0
°
C to +70
°
C
TC7135CPI
28-Pin Plastic DIP
0
°
C to +70
°
C
TC7135
–5V
V
REF IN
ANALOG
COMMON
INT OUT
AZ IN
BUFF OUT
C+
CREF
–INPUT
+INPUT
V
D5
B1
B2
UR
OR
STROBE
RUN/HOLD
DGND
POL
CLOCK
BUSY
D1
D2
D3
0.1 μF
0.47 μF
1 μF
ANALOG
GROUND
100 k
0.1
μF
INPUT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
+5V
28
27
26
25
24
23
22
21
20
19
18
TC04
+5V
1/4 CD4030
CLOCK IN
+5V
BP
D
D
D
D
1
2
3
4
4-1/2 DIGIT LCD
SEGMENT
D
R
I
V
E
5
31
32
33
34
30
29
28
27
TC7211A
SEG
OUT
OSC
GND
36
+5V
+5V
1
CD4081
11615 1412 5 3 4
CD4054A
7 8 13 1110 9 2 6
OPTIONAL
CAP
35
15
120 Hz = 3 READING/SEC
BACKPLANE
B
B
B
B
3
2
1
0
D4
B8
B4
17
16
100 k
100 k
6.8 k
1 μF
+
V+
2,3,4
6–26
37–40
–
+5V
FEATURES
Low Roll-Over Error .........................
±
1 Count Max
I
Guaranteed Nonlinearity Error ........
±
1 Count Max
I
Guaranteed Zero Reading for 0V Input
I
True Polarity Indication at Zero for Null Detection
I
Multiplexed BCD Data Output
I
TTL-Compatible Outputs
I
Differential Input
I
Control Signals Permit Interface to UARTs and
μ
Processors
I
Auto-Ranging Supported With Overrange and
Underrange Signals
I
Blinking Display Visually Indicates Overrange
Condition
I
Low Input Current............................................. 1 pA
I
Low Zero Reading Drift ............................... 2
μ
V/
°
C
I
Interfaces to TC7211A (LCD) and TC7212A (LED)
Display Drivers
I
Available in DIP and Surface-Mount Packages
I
TYPICAL 4-1/2 DIGIT DVM WITH LCD
4-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTER
TC7135-10 11/6/96