TC811 TelCom Semiconductor, TC811 Datasheet - Page 11

• Manufacturer Part Number: TC811
• Description: 3-1/2 DIGIT A/D CONVERTER WITH HOLD AND DIFFERENTIAL REFERENCE INPUTS
• Manufacturer: TelCom Semiconductor

Liquid Crystal Display Sources
plays to interface with the TC811 3-1/2 digit analog-to-digital
converter.
Manufacturer
Crystaloid
Electronics
AND
EPSON
Hamlin, Inc.
*
Oscillator Crystal Source
Manufacturer
STATEK
Ratiometric Resistance Measurements
ence 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.
standard and a current is passed through the pair (Figure
11). The voltage developed across the unknown is applied
to the input and the voltage across the known resistor
applied to the reference input. If the unknown equals the
standard, the input voltage will equal the reference voltage
and the display will read 1000. The displayed reading can be
determined from the following expression:
R
3-1/2 DIGIT A/D CONVERTER WITH HOLD AND
DIFFERENTIAL REFERENCE INPUTS
NOTE: Contact LCD manufacturer for full product listing/specifications.
STANDARD
Several LCD manufactures supply standard LCD dis-
The TC811 true differential input and differential refer-
The unknown resistance is put in series with a known
Displayed reading =
The display will overrange for R
TELCOM SEMICONDUCTOR, INC.
.
Address/Phone
5282 Hudson Dr.,
Hudson, OH 44236
216-655-2429
770 Airport Blvd.,
Burlingame, CA 94010
415-347-9916
3415 Kashikawa St.,
Torrence, CA 90505
212-534-0360
612 E. Lake St.,
Lake Mills, WI 53551
414-648-2361
Address/Phone
512 N-Main
Orange, CA 92668
714-639-7810
R
R
STANDARD
UNKNOWN
Representative
Part Numbers
C5335, H5535,
T5135, SX440
FE 0801,
FE 0203
LD-B709BZ
LD-H7992AZ
3902, 3933, 3903
x 1000
UNKNOWN
Representative
Part Numbers
CX-1V 40.0
2 X
*
Figure 11. Low Parts Count Ratio Metric Resistance Measurement
R
UNKNOWN
R
STANDARD
Figure 10. TC811 Internal Voltage Reference Connection
26
V –
SET V REF = 1/2 V FULL SCALE
TC811
COMMON
9V
ANALOG
V
V
V
V
ANALOG
COMMON
+
REF
IN
IN
+
V REF
V REF
–
REF
+
–
+
–
V +
38
TC811
V + HLDR
36
33
32
V REF
240k
10k
LCD
TC811
3-147
1
2
3
4
5
6
7
8