
1
3-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTER
WITH HOLD AND DIFFERENTIAL REFERENCE INPUTS
TC811
TC811CPL
THOUSANDS
HUNDREDS
TENS
UNITS
4
39
OSC
V
TEST
TO SWITCH DRIVERS
FROM COMPARATOR OUTPUT
CLOCK
7 SEGMENT
DECODE
40
2
OSC1
CONTROL LOGIC
26
500
DATA LATCH
+
BUFF
CREF
–
RINT
V
+
CAZ
VINT
28
29
27
34
36
35
10
A
31
ZI & A/Z
INT
AZ & DE (
±)
32
INT
26
INTEGRATOR
TO
DIGITAL
SECTION
DE (+)
DE
(–)
DE
(+)
DE (–)
ANALOG
COMMON
C REF
+
V IN
+
V IN
–
V
CINT
VREF
+
VREF
–
ZI &
A/Z
CREF
+
33
+
–
LCD SEGMENT DRIVERS
200
BACKPLANE
fOSC
V
–
VTH
= 1V
V
–
+
–
INTERNAL DIGITAL GOUND
LOW
TEMPCO
VREF
COMPARATOR
–
A/Z
ZI
V+– 3.0V
38
470k
10pF
7 SEGMENT
DECODE
7 SEGMENT
DECODE
21
TYPICAL SEGMENT OUTPUT
INTERNAL DIGITAL GROUND
SEGMENT
OUTPUT
V
+
0.5mA
2mA
6.2V
LCD DISPLAY
+
–
38
20pF
V
+
V
+
22M
HLDR
≈70k
A/Z
30
32kHz
1
FUNCTIONAL BLOCK DIAGRAM
ORDERING INFORMATION
Temp.
Max VREF
Part No.
Package
Range
Temp. Co.
TC811CKW
44-Pin PQFP
0
°C to +70°C 75 ppm/°C
TC811CPL
40-Pin Plastic DIP 0
°C to +70°C 75 ppm/°C
3-1/2 DIGIT ANALOG-TO-DIGITAL CONVERTER WITH HOLD AND
DIFFERENTIAL REFERENCE INPUTS
FEATURES
s
Differential Reference Input
s
Display Hold Function
s
Fast Over-Range Recovery, Guaranteed Next
Reading Accuracy
s
Low Temperature Drift Internal
Reference ....................................... 35ppm/
°C (Typ)
s
Guaranteed Zero Reading With Zero Input
s
Low Noise ..................................................... 15
V
p-p
s
High Resolution (0.05%) and Wide Dynamic
Range (72 dB)
s
High Impedance Differential Input
s
Low Input Leakage Current .................... 1pA (Typ)
10pA Max
s
Direct LCD Drive -No External Components
s
Precision Null Detection with True Polarity at Zero
s
Crystal Clock Oscillator
s
Available in DIP, Compact Flat Package or PLCC
s
Convenient 9V Battery Operation with
Low Power Dissipation (600
A Typical, 1mW
Maximum)
TYPICAL APPLICATIONS
s
Thermometry
s
Digital Meters
— Voltage/Current/Power
— pH Measurement
— Capacitance/Inductance
— Fluid Flow Rate/Viscosity
— Humidity
— Position
s
Panel Meters
s
LVDT Indicators
s
Portable Instrumentation
s
Digital Scales
s
Process Monitors
s
Gaussometers
s
Photometers
TC811-7 11/5/96 TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices.