TC7126 View Datasheet(PDF) - TelCom Semiconductor Inc => Microchip
Part Name
Description
Manufacturer
TC7126 Datasheet PDF : 13 Pages
| |||
3-1/2 DIGIT
ANALOG-TO-DIGITAL CONVERTERS
1
TC7126
TC7126A
200
180
NO
160
MAXIMUM
SPECIFIED
140
TYPICAL
120
100
NO
GUARANTEED MAXIMUM
80
MAXIMUM SPECIFIED
TYPICAL
60
40
TYPICAL
20
TC7126A
ICL7126
ICL7136
0
Figure 7. Analog Common Temperature Coefficient
APPLICATIONS INFORMATION
Liquid Crystal Display Sources
Several manufacturers supply standard LCDs to inter-
face with the TC7126A 3-1/2 digit analog-to-digital con-
verter.
Manufacturer Address/Phone
Representative
Part Numbers*
Crystaloid
Electronics
5282 Hudson Dr.,
Hudson, OH 44236
216-655-2429
C5335, H5535,
T5135, SX440
AND
720 Palomar Avenue
Sunnyvale, CA 94086
408-523-8200
FE 0801,
FE 0203
VGI, Inc.
1800 Vernon St., Ste. 2 I1048, I1126
Roseville, CA 95678
916-783-7878
Hamlin, Inc.
612 E. Lake St.,
Lake Mills, WI 53551
414-648-2361
3902, 3933, 3903
*NOTE: Contact LCD manufacturer for full product listing/specifications.
Decimal Point and Annunciator Drive
The TEST pin is connected to the internally-generated
digital logic supply ground through a 500Ω resistor. The
TEST pin may be used as the negative supply for external
CMOS gate segment drivers. LCD annunciators for decimal
points, low battery indication, or function indication may be
added without adding an additional supply. No more than 1
mA should be supplied by the TEST pin: its potential is
approximately 5V below V+.
TELCOM SEMICONDUCTOR, INC.
9V
+
2
26
1
V–
V+
240 kΩ
TC7126A
VR+EF 36
VREF
10 kΩ
3
VR– EF 35
ANALOG 32
COMMON
SET VREF = 1/2 VFULL SCALE
Figure 8. TC7126A Internal Voltage Reference Connection
4
Flat Package
The TC7126A is available in an epoxy 64-pin formed-
lead flat package. A test socket for the TC7126ACBQ device
is available:
Part No.
IC 51-42
Manufacturer: Yamaichi
5
Distribution: Nepenthe Distribution
2471 East Bayshore
Suite 520
Palo Alto, CA 94043
(415) 856-9332
6 Ratiometric Resistance Measurements
The TC7126A's true differential input and differential
reference make ratiometric readings possible. In ratiometric
operation, an unknown resistance is measured with respect
to a known standard resistance. No accurately-defined
reference voltage is needed.
The unknown resistance is put in series with a known
standard and a current passed through the pair. The voltage
7 developed across the unknown is applied to the input and
the voltage across the known resistor applied to the refer-
ence input. If the unknown equals the standard, the display
will read 1000. The displayed reading can be determined
from the following expression:
Displayed reading = RUNKNOWN ϫ 1000.
RSTANDARD
The display will overrange for RUNKNOWN ≥
2 ϫ RSTANDARD.
8
3-227
Share Link: 