2002 Microchip Technology Inc.
DS21455B-page 1
TC7106/A/TC7107/A
Features
Internal Reference with Low Temperature Drift
- TC7106/7: 80ppm/C Typical
- TC7106A/7A: 20ppm/C Typical
Drives LCD (TC7106) or LED (TC7107)
Display Directly
Zero Reading with Zero Input
Low Noise for Stable Display
Auto-Zero Cycle Eliminates Need for Zero
Adjustment
True Polarity Indication for Precision Null
Applications
Convenient 9V Battery Operation (TC7106A)
High Impedance CMOS Differential Inputs: 10
12
Differential Reference Inputs Simplify Ratiometric
Measurements
Low Power Operation: 10mW
Applications
Thermometry
Bridge Readouts: Strain Gauges, Load Cells, Null
Detectors
Digital Meters: Voltage/Current/Ohms/Power, pH
Digital Scales, Process Monitors
Portable Instrumentation
Device Selection Table
General Description
The TC7106A and TC7107A 3-1/2 digit direct display
drive analog-to-digital converters allow existing 7106/
7107 based systems to be upgraded. Each device has
a precision reference with a 20ppm/C max tempera-
ture coefficient. This represents a 4 to 7 times improve-
ment over similar 3-1/2 digit converters. Existing 7106
and 7107 based systems may be upgraded without
changing external passive component values. The
TC7107A drives common anode light emitting diode
(LED) displays directly with 8mA per segment. A low
cost, high resolution indicating meter requires only a
display,
four
resistors,
and
four
capacitors.The
TC7106A low power drain and 9V battery operation
make it suitable for portable applications.
The TC7106A/TC7107A reduces linearity error to less
than 1 count. Rollover error the difference in readings
for equal magnitude, but opposite polarity input signals,
is below 1 count. High impedance differential inputs
offer 1pA leakage current and a 10
12
input imped-
ance. The differential reference input allows ratiometric
measurements for ohms or bridge transducer mea-
surements. The 15
V
PP
noise performance ensures a
"rock solid" reading. The auto-zero cycle ensures a
zero display reading with a zero volts input.
Package
Code
Package
Pin Layout
Temperature
Range
CPI
40-Pin PDIP
Normal
0
C to +70
C
IPL
40-Pin PDIP
Normal
-25
C to +85
C
IJL
40-Pin CERDIP
Normal
-25
C to +85
C
CKW
44-Pin PQFP
Formed Leads
0
C to +70
C
CLW
44-Pin PLCC
--
0
C to +70
C
3-1/2 Digit Analog-to-Digital Converters
TC7106/A/TC7107/A
DS21455B-page 2
2002 Microchip Technology Inc.
Package Type
TC7106ACPL
TC7107AIPL
44-Pin PLCC
44-Pin PQFP
40-Pin CERDIP
40-Pin PDIP
1
2
3
4
OSC1
5
6
7
8
9
10
11
12
TEST
V
REF
+
ANALOG
COMMON
C
AZ
V+
D
2
Normal Pin
Configuration
13
14
15
16
17
18
19
20
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
C
2
B
2
A
2
F
2
E
2
D
3
B
3
F
3
E
3
AB
4
(Minus Sign)
(Minus Sign)
10's
100's
1000's
(7106A/7107A)
100's
OSC2
OSC3
V
REF
-
C
REF
+
C
REF
-
V
IN
+
V
IN
-
V
BUFF
V
INT
V-
G
2
C
3
A
3
G
3
BP/GND
POL
TC7106AIJL
TC7107AIJL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
100's
1000's
100's
Reverse
Configuration
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21
D
1
C
1
B
1
A
1
F
1
G
1
E
1
1's
V+
D
2
C
2
B
2
A
2
F
2
E
2
D
3
B
3
F
3
E
3
AB
4
POL
D
1
C
1
B
1
A
1
F
1
G
1
E
1
1's
10's
OSC1
TEST
V
REF
+
ANALOG
COMMON
C
AZ
OSC2
OSC3
V
REF
-
C
REF
+
C
REF
-
V
IN
+
V
IN
-
V
BUFF
V
INT
V-
G
2
C
3
A
3
G
3
BP/GND
(7106A/7107A)
27
26
25
24
23
7
8
9
10
11
NC
G
2
NC
NC
TEST
OSC3
NC
OSC2
OSC1
V+
D
1
C
1
B
1
12
13
14
15
16
17
18
19
20
21
22
38
37
36
35
34
REF HI
A
1
F
1
TC7106ACKW
TC7107ACKW
39
40
41
42
43
44
28
29
30
31
32
33
6
5
4
3
2
1
REF LO
C
REF
C
REF
COM
IN HI
IN LO
A/Z
BUFF
INT
V-
G
1
E
1
D
2
C
2
B
2
A
2
F
2
E
2
D
3
C
3
A
3
G
3
BP/GND
POL
AB
4
E
3
F
3
B
3
33
32
31
30
29
13
14
15
16
17
REF LO
C
REF
F
1
G
1
E
1
D
2
C
2
NC
B
2
A
2
F
2
E
2
D
3
18
19
20
21
22
23
24
25
26
27
28
44
43
42
41
40
A
1
B
3
F
3
TC7106ACLW
TC7107ACLW
1
2
3
4
5
6
34
35
36
37
38
39
12
11
10
9
8
7
B
1
C
1
D
1
V+
NC
OSC1
OSC2
OSC3
TEST
REF HI
E
3
AB
4
POL
NC
BP/GND
G
3
A
3
C
3
G
2
C
REF
COMMON
IN HI
NC
IN LO
A/Z
BUFF
INT
V-
2002 Microchip Technology Inc.
DS21455B-page 3
TC7106/A/TC7107/A
Typical Application
V
REF
+
TC7106/A
TC7107/A
9V
V
REF
33
34
24k
1k
29
36
39
38
40
0.47
F
0.1
F
V-
OSC1
OSC3
OSC2
To Analog
Common (Pin 32)
3 Conversions/Sec
200mV Full Scale
C
OSC
100k
47k
0.22
F
C
REF
-
C
REF
+
V
IN
+
V
IN
-
ANALOG
COMMON
V
INT
V
BUFF
C
AZ
20
21
Segment
Drive
2 - 19
22 - 25
POL
BP
V+
Minus Sign
Backplane
Drive
28
R
OSC
100pF
LCD Display (TC7106/A) or
Common Node w/ LED
Display (TC7107/A)
27
100mV
1
26
35
V
REF
-
+
31
0.01
F
Analog
Input
+
1M
30
32
TC7106/A/TC7107/A
DS21455B-page 4
2002 Microchip Technology Inc.
1.0
ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings*
TC7106A
Supply Voltage (V+ to V-) ....................................... 15V
Analog Input Voltage (either Input) (Note 1) ... V+ to V-
Reference Input Voltage (either Input) ............ V+ to V-
Clock Input ................................................... Test to V+
Package Power Dissipation (T
A
70C) (Note 2):
40-Pin CERDIP .......................................2.29W
40-Pin PDIP ............................................1.23W
44-Pin PLCC ...........................................1.23W
44-Pin PQFP ...........................................1.00W
Operating Temperature Range:
C (Commercial) Devices .............. 0C to +70C
I (Industrial) Devices ................ -25C to +85C
Storage Temperature Range .............. -65C to +150C
TC7107A
Supply Voltage (V+) ...............................................+6V
Supply Voltage (V-)..................................................-9V
Analog Input Voltage (either Input) (Note 1) ... V+ to V-
Reference Input Voltage (either Input) ............ V+ to V-
Clock Input ..................................................GND to V+
Package Power Dissipation (T
A
70C) (Note 2):
40-Pin CERDip ........................................2.29W
40-Pin PDIP ............................................1.23W
44-Pin PLCC ...........................................1.23W
44-Pin PQFP ...........................................1.00W
Operating Temperature Range:
C (Commercial) Devices .............. 0C to +70C
I (Industrial) Devices ................ -25C to +85C
Storage Temperature Range .............. -65C to +150C
*Stresses above those listed under "Absolute Maximum
Ratings" may cause permanent damage to the device. These
are stress ratings only and functional operation of the device
at these or any other conditions above those indicated in the
operation sections of the specifications is not implied.
Exposure to Absolute Maximum Rating conditions for
extended periods may affect device reliability.
TC7106/A AND TC7107/A ELECTRICAL SPECIFICATIONS
Electrical Characteristics: Unless otherwise noted, specifications apply to both the TC7106/A and TC7107/A at T
A
= 25C,
f
CLOCK
= 48kHz. Parts are tested in the circuit of the Typical Operating Circuit.
Symbol
Parameter
Min
Typ
Max
Unit
Test Conditions
Z
IR
Zero Input Reading
-000.0
000.0
+000.0
Digital
Reading
V
IN
= 0.0V
Full Scale = 200.0mV
Ratiometric Reading
999
999/1000
1000
Digital
Reading
V
IN
= V
REF
V
REF
= 100mV
R/O
Rollover Error (Difference in Reading for
Equal Positive and Negative
Reading Near Full Scale)
-1
0.2
+1
Counts
V
IN
- = + V
IN
+
200mV
Linearity (Max. Deviation from Best
Straight Line Fit)
-1
0.2
+1
Counts
Full Scale = 200mV or
Full Scale = 2.000V
Note
1:
Input voltages may exceed the supply voltages, provided the input current is limited to 100
A.
2:
Dissipation rating assumes device is mounted with all leads soldered to printed circuit board.
3:
Refer to "Differential Input" discussion.
4:
Backplane drive is in phase with segment drive for "OFF" segment, 180 out of phase for "ON" segment.
Frequency is 20 times conversion rate. Average DC component is less than 50mV.
2002 Microchip Technology Inc.
DS21455B-page 5
TC7106/A/TC7107/A
CMRR
Common Mode Rejection Ratio (Note 3)
--
50
--
V/V
V
CM
= 1V, V
IN
= 0V,
Full Scale = 200.0mV
e
N
Noise (Peak to Peak Value not Exceeded
95% of Time)
--
15
--
V
V
IN
= 0V
Full Scale - 200.0mV
I
L
Leakage Current at Input
--
1
10
pA
V
IN
= 0V
Zero Reading Drift
--
0.2
1
V/C
V
IN
= 0V
"C" Device = 0C to +70C
--
1.0
2
V/C
V
IN
= 0V
"I" Device = -25C to +85C
TC
SF
Scale Factor Temperature Coefficient
--
1
5
ppm/C
V
IN
= 199.0mV,
"C" Device = 0C to +70C
(Ext. Ref = 0ppmC)
--
--
20
ppm/C
V
IN
= 199.0mV
"I" Device = -25C to +85C
I
DD
Supply Current (Does not include LED
Current For TC7107/A)
--
0.8
1.8
mA
V
IN
= 0.8
V
C
Analog Common Voltage
(with Respect to Positive Supply)
2.7
3.05
3.35
V
25k
Between Common and
Positive Supply
V
CTC
Temperature Coefficient of Analog
Common (with Respect to Positive Supply)
--
--
--
--
25k
Between Common and
Positive Supply
7106/7/A
7106/7
20
80
50
--
ppm/C
ppm/C
0C
T
A
+70C
("C" Commercial Temperature
Range Devices)
V
CTC
Temperature Coefficient of Analog
Common (with Respect to Positive Supply)
--
--
75
ppm/C
0C
T
A
+70C
("I" Industrial Temperature
Range Devices)
V
SD
TC7106A ONLY Peak to Peak
Segment Drive Voltage
4
5
6
V
V+ to V- = 9V
(Note 4)
V
BD
TC7106A ONLY Peak to Peak
Backplane Drive Voltage
4
5
6
V
V+ to V- = 9V
(Note 4)
TC7107A ONLY
Segment Sinking Current (Except Pin 19)
5
8.0
--
mA
V+ = 5.0V
Segment Voltage = 3V
TC7107A ONLY
Segment Sinking Current (Pin 19)
10
16
--
mA
V+ = 5.0V
Segment Voltage = 3V
TC7106/A AND TC7107/A ELECTRICAL SPECIFICATIONS (CONTINUED)
Electrical Characteristics: Unless otherwise noted, specifications apply to both the TC7106/A and TC7107/A at T
A
= 25C,
f
CLOCK
= 48kHz. Parts are tested in the circuit of the Typical Operating Circuit.
Symbol
Parameter
Min
Typ
Max
Unit
Test Conditions
Note
1:
Input voltages may exceed the supply voltages, provided the input current is limited to 100
A.
2:
Dissipation rating assumes device is mounted with all leads soldered to printed circuit board.
3:
Refer to "Differential Input" discussion.
4:
Backplane drive is in phase with segment drive for "OFF" segment, 180 out of phase for "ON" segment.
Frequency is 20 times conversion rate. Average DC component is less than 50mV.
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