TelCom TC7106, TC7106A, TC7107, TC7107A User Manual

查询TC7107RCPL供应商

3-1/2 Digit A/D Converters

TC7106

TC7106A

TC7107

TC7107A

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

■ Guaranteed 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 9 V Battery Operation (TC7106A)

■ High Impedance CMOS Differential Inputs.... 1012Ω

■ Differential Reference Inputs Simplify Ratiometric

Measurements

■ Low Power Operation..................................... 10mW

ORDERING INFORMATION
PART CODE TC710X X X XXX

6 = LCD
7 = LED

A or blank*
R (reversed pins) or blank (CPL pkg only)

}

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 temperature coeffi­cient. This represents a 4 to 7 times improvement 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
differential reference input allows ratiometric measurements
for ohms or bridge transducer measurements. The
15µV

noise performance guarantees a “rock solid” read-

P–P

ing. The auto-zero cycle guarantees a zero display read­ing with a zero-volts input.

12

Ω input impedance. The

* "A" parts have an improved reference TC

Package Code (see below):

Package Temperature
Code Package Pin Layout Range

CKW 44-Pin PQFP Formed Leads 0°C to +70°C
CLW 44-Pin PLCC — 0°C to +70°C
CPL 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

AVAILABLE PACKAGES

40-Pin Plastic DIP

44-Pin Plastic Quad Flat

Package Formed Leads

40-Pin CERDIP

44-Pin Plastic Chip

Carrier PLCC

0.1µF
33

+

ANALOG

INPUT

–

1MΩ

0.01µF

47kΩ

0.22µF

0.47µF

34

31

30

32

28

V

C

29
27

–

+

C

C

REF

REF

+

V

IN

TC7106/A

–

V

IN

TC7107/A

ANALOG
COMMON

BUFF

AZ

V

INT

OSC
39 38 40

2

R

OSC

100kΩ

OSC

3

C

OSC

100pF

OSC

SEGMENT

2–19

DRIVE

22–25

20

POL

21

BP

1

+

V

+

36

V

REF

–

35

V

REF

26

–

V

1

3 CONVERSIONS/SEC
200mV FULL SCALE

Figure 1. TC7106/A/7/A Typical Operating Circuit

LCD DISPLAY (TC7106/A) OR

COMMON ANODE LED

DISPLAY (TC7107/A)

MINUS SIGN

V

REF

100mV

BACKPLANE
DRIVE

24kΩ

+

9V

1kΩ

TO ANALOG
COMMON (PIN 32)

© 2001 Microchip Technology Inc. DS21455A

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

3-1/2 Digit A/D Converters

ABSOLUTE MAXIMUM RATINGS*
TC7106A

Supply Voltage (V+ to V–)...........................................15 V

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 (Note 2) (TA ≤ 70°C)

CerDIP..............................................................2.29W

Plastic DIP ........................................................1.23W

PLCC ................................................................1.23W

PQFP................................................................1.00W

Operating Temperature

“C” Devices............................................0°C to +70°C

“I” Devices ........................................– 25°C to +85°C

Storage Temperature ............................ – 65°C to +150°C

Lead Temperature (Soldering, 60 sec) ................... 300°C

TC7107A

Supply Voltage

+

V

................................................................................................ +6 V

–

V

............................................................................................... – 9 V

Analog Input Voltage (either input) (Note 1)......... V+ to V

Reference Input Voltage (either input) ................. V+ to V

Clock Input ....................................................... GND to V

Power Dissipation (Note 2) (TA ≤ 70°C)

40-Pin CerDIP Package ...................................2.29W

–
–
+

40-Pin Plastic DIP.............................................1.23W

44-Pin PLCC.....................................................1.23W

44-Pin PQFP ....................................................1.00W

Operating Temperature

“C” Devices............................................0°C to +70°C

“I” Devices ........................................– 25°C to +85°C

Storage Temperature ............................ – 65°C to +150°C

Lead Temperature (Soldering, 10 sec) ................. +300°C

*Static-sensitive device. Unused devices must be stored in conductive
material. Protect devices from static discharge and static fields. 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 operational sections of the specifications is not implied.
Exposure to Absolute Maximum Rating Conditions for extended periods
may affect device reliability.

–
–

+

ELECTRICAL CHARACTERISTICS (Note 3)

TC7106/A & TC7107/A

Parameters Test Conditions Min Typ Max Unit

Zero Input Reading VIN = 0.0 V – 000.0 ±000.0 +000.0 Digital

Full-Scale = 200.0mV Reading

Ratiometric Reading VIN = V

Roll-Over Error (Difference in V
Reading for Equal Positive and
Negative Reading Near Full-Scale)

Linearity (Max. Deviation From Full-Scale = 200mV – 1 ±0.2 +1 Counts
Best Straight Line Fit) or Full-Scale = 2.000 V

Common-Mode V
Rejection Ratio (Note 4) Full Scale = 200.0 mV

Noise (Pk – Pk Value Not V
Exceeded 95% of Time) Full-Scale = 200.0mV

Leakage Current @ Input VIN = 0 V — 1 10 pA
Zero Reading Drift V

Scale Factor VIN = 199.0mV,
Temperature Coefficient “C” Device = 0°C to +70°C — 1 5 ppm/°C

Supply Current (Does Not VIN = 0 — 0.8 1.8 mA
Include LED Current For TC7107/A)

© 2001 Microchip Technology Inc.

REF

V

= 100 mV Reading

REF
–

+

= +V

IN

CM

IN

IN

“C” Device = 0°C to +70°C — 0.2 1 µV/°C
VIN = 0 V
“I” Device = – 25°C to +85°C — 1.0 2 µV/°C

(Ext. Ref = 0ppm°C)
V

IN

“I” Device = – 25°C to +85°C

≅ 200mV – 1 ±0.2 +1 Counts

IN

= ±1V, VIN = 0V, — 50 — µV/V

= 0 V — 15 — µV

= 0 V

= 199.0mV — — 20 ppm/°C

2

999 999/1000 1000 Digital

© 2001 Microchip Technology Inc. DS21455A

3-1/2 Digit A/D Converters

TC7106

TC7106A

TC7107

TC7107A

ELECTRICAL CHARACTERISTICS (Cont.) (Note 3)

TC7106/A & TC7107/A

Parameters Test Conditions Min Typ Max Unit

Analog Common Voltage 25kΩ Between Common 2.7 3.05 3.35 V
(With Respect to Pos. Supply) and Pos. Supply

Temp. Coeff. of 25kΩ Between Common
Analog Common and Pos. Supply
(With Respect 0°C ≤ T
to Pos. Supply) ("C", Commercial Temp. Range Devices) 7106/7 80 — ppm/°C

Temp. Coeff. of 25kΩ Between Common
Analog Common and Pos. Supply
(With Respect – 25°C ≤ T
to Pos. Supply) (“I,” Industrial Temp. Range Devices)

TC7106A ONLY Pk – Pk V+ to V– = 9V 4 5 6 V
Segment Drive Voltage (Note 5)

TC7106A ONLY Pk – Pk V+ to V– = 9V 4 5 6 V
Backplane Drive Voltage (Note 5)

TC7107A ONLY V+ = 5.0V 5 8.0 — mA
Segment Sinking Current (Except Pin 19) Segment Voltage = 3V

TC7107A ONLY V
Segment Sinking Current (Pin 19) Segment Voltage = 3V

NOTES: 1. Input voltages may exceed the supply voltages provided the input current is limited to ±100µA.

2. Dissipation rating assumes device is mounted with all leads soldered to printed circuit board.

3. Unless otherwise noted, specifications apply to both the TC7106/A and TC7107/A at TA = 25°C, f
circuit of Figure 1.

4. Refer to “Differential Input” discussion.

5. 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.

≤ +70°C 7106 A/7A 20 50 ppm/°C

A

≤ 85°C — — 75 ppm/°C

A

+

= 5.0V 10 16 — mA

= 48 kHz. Parts are tested in the

CLOCK

© 2001 Microchip Technology Inc. DS21455A

3

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

PIN CONFIGURATIONS

3-1/2 Digit A/D Converters

V
D
C
B
A

1's

F
G
E
D
C
B

10's

A
F
E
D
B

100's

F
E

1000's

1

A

AB
POL

(MINUS SIGN)

B1C1D1V+NC

+

1
2

CONFIGURATION

1

3

1

4

1

5

1

6

1

7

1

8

1

9

2

10

2

11

2

12

2

13

2

14

2

15

3

16

3

17

3

18

3

19

4

20

NORMAL PIN

TC7106ACPL

TC7107AIPL

OSC1OSC2OSC3TEST

123456

44 43 42 41 40

40

OSC

39

OSC

38

OSC

37

TEST

36

V

35

V
C

34

C

33

ANALOG

32

COMMON

31

V
V

30

C

29

28

V

27

V

26

V

25

G

24

C

23

A

22

G

21

BP/GND
(7106A/7107A)

+
REF

–

REF
+
REF

–

REF

+
IN

–

IN
AZ

BUFF

INT

–

2
3
3
3

REF HI

1
2
3

100's

OSC
OSC

OSC

TEST

+

V

REF

–

V

REF
+

C

REF

–

C

REF

ANALOG

COMMON

V
V

C

AZ

V

BUFF

V

INT

V

G
C

100's

A
G

BP/GND

(7106A/7107A)

1

1

2

2

3

3

4
5
6
7
8
9

+

10

IN

–

11

IN

12
13
14

–

15

16

2

17

3

18

3

19

3

20

REF HI

REVERSE PIN

CONFIGURATION

TC7106AIJL
TC7107AIJL

REFCREF

REF LO

C

+

40

V

D

39

1

C

38

1

B

37

1

A

36

1

F

35

1

G

34

1

E

33

1

32

D

2

31

C

2

B

30

2

A

29

2

F

28

2

E

27

2

26

D

3

B

25

3

F

24

3

23

E

3

22

AB

4

21

POL
(MINUS SIGN)

COM

IN HI

IN LO

394041424344

38 37 36 35 34

1's

10's

100's

A/Z

1000's

BUFF

INT

–

V

7

F

1

8

G

1

9

E

1

10

D

2

11

C

2

12

NC

13

B

2

14

A

2

15

F

2

16

E

2

17

D

3

18 19 20 21 22 23 24 25 26 27 28

3F3

B

© 2001 Microchip Technology Inc.

3AB4

E

TC7106ACLW
TC7107ACLW

(PLCC)

NC

POL

3A3C3G2

G

BP/GND

39
38
37
36
35
34
33
32
31
30
29

REF LO
C

REF

C

REF

COMMON
IN HI
NC
IN LO
A/Z
BUFF
INT

–

V

1

NC

2

NC

3

TEST

4

OSC

3

5

NC

6

OSC

2

7

OSC

1
+

8

V

9

D

1

10

C

1

11

B

1

12 13 14 15 16 17 18 19 20 21 22

1F1

A

4

TC7106ACKW
TC7107ACKW

(FLAT PACKAGE)

1E1D2C2B2A2F2E2D3

G

© 2001 Microchip Technology Inc. DS21455A

33
32
31
30
29
28
27
26
25
24
23

NC
G

2

C

3

A

3

G

3

BP/GND
POL
AB

4

E

3

F

3

B

3

3-1/2 Digit A/D Converters

PIN DESCRIPTION

(Pin No. (Pin No.

40-Pin PDIP 40-Pin PDIP

(Normal)) (Reverse)) Symbol Description

1 (40) V
2 (39) D
3 (38) C
4 (37) B
5 (36) A
6 (35) F
7 (34) G
8 (33) E

9 (32) D
10 (31) C
11 (30) B
12 (29) A
13 (28) F
14 (27) E
15 (26) D
16 (25) B
17 (24) F
18 (23) E
19 (22) AB
20 (21) POL Activates the negative polarity display.
21 (20) BP LCD Backplane drive output (TC7106A).

22 (19) G
23 (18) A
24 (17) C
25 (16) G
26 (15) V
27 (14) V

28 (13) V

29 (12) C

30 (11) V
31 (10) V
32 (9) ANALOG This pin is primarily used to set the analog common-mode voltage

33 (8) C

+

1
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
3

4

GND

3
3
3
2

–

INT

BUFF

AZ

–

IN
+

IN

COMMON

–

REF

Positive supply voltage.
Activates the D section of the units display.
Activates the C section of the units display.
Activates the B section of the units display.
Activates the A section of the units display.
Activates the F section of the units display.
Activates the G section of the units display.
Activates the E section of the units display.
Activates the D section of the tens display.
Activates the C section of the tens display.
Activates the B section of the tens display.
Activates the A section of the tens display.
Activates the F section of the tens display.
Activates the E section of the tens display.
Activates the D section of the hundreds display.
Activates the B section of the hundreds display.
Activates the F section of the hundreds display.
Activates the E section of the hundreds display.
Activates both halves of the 1 in the thousands display.

Digital ground (TC7107A).
Activates the G section of the hundreds display.
Activates the A section of the hundreds display.
Activates the C section of the hundreds display.
Activates the G section of the tens display.
Negative power supply voltage.
Integrator output. Connection point for integration capacitor. See

INTEGRATING CAPACITOR section for more details
Integration resistor connection. Use a 47kΩ resistor for a 200mV full-

scale range and a 470kΩ resistor for 2V full-scale range.
The size of the auto-zero capacitor influences system noise. Use a

0.47µF capacitor for 200mV full scale, and a 0.047µF capacitor for
2V full scale. See Paragraph on AUTO-ZERO CAPACITOR for more
details.

The analog LOW input is connected to this pin.
The analog HIGH input signal is connected to this pin.

for battery operation or in systems where the input signal is
referenced to the power supply. It also acts as a reference voltage
source. See paragraph on ANALOG COMMON for more details.

See pin 34.

TC7106

TC7106A

TC7107

TC7107A

© 2001 Microchip Technology Inc. DS21455A

5

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

PIN DESCRIPTION (Cont.)

(Pin No. (Pin No.

40-Pin PDIP 40-Pin PDIP

(Normal) (Reverse) Symbol Description

34 (7) C

35 (6) V
36 (5) V

37 (4) Test Lamp test. When pulled HIGH (to V

38 (3) OSC
39 (2) OSC
40 (1) OSC

+
REF

–

REF
+

REF

A 0.1µF capacitor is used in most applications. If a large common­mode voltage exists (for example, the V
common), and a 200mV scale is used, a 1µF capacitor is recom­mended and will hold the roll-over error to 0.5 count.

See pin 36.
The analog input required to generate a full-scale output (1999

counts). Place 100mV between pins 35 and 36 for 199.9mV
full-scale. Place 1V between pins 35 and 36 for 2V full scale. See
paragraph on REFERENCE VOLTAGE.

and the display should read –1888. It may also be used as a negative
supply for externally-generated decimal points. See paragraph under
TEST for additional information.

3
2
1

See pin 40.
See pin 40.
Pins 40, 39, 38 make up the oscillator section. For a 48kHz clock

(3 readings per section), connect pin 40 to the junction of a 100kΩ
resistor and a 100pF capacitor. The 100kΩ resistor is tied to pin 39
and the 100pF capacitor is tied to pin 38.

3-1/2 Digit A/D Converters

–

pin is not at analog

IN

+

) all segments will be turned on

General Theory of Operation
Dual Slope Conversion Principles

(All Pin Designations Refer to the 40-Pin DIP)

The TC7106A and TC7107A are dual slope, integrating
analog-to-digital converters. An understanding of the dual
slope conversion technique will aid in following the detailed
operation theory.

The conventional dual slope converter measurement
cycle has two distinct phases:

• Input Signal Integration

• Reference Voltage Integration (Deintegration)

The input signal being converted is integrated for a fixed
time period (TSI). Time is measured by counting clock
pulses. An opposite polarity constant reference voltage is
then integrated until the integrator output voltage returns to
zero. The reference integration time is directly proportional
to the input signal (TRI). (Figure 2A).

In a simple dual slope converter a complete conversion
requires the integrator output to “ramp-up” and “ramp-
down.”

A simple mathematical equation relates the input signal,
reference voltage and integration time:

T

1

RC

© 2001 Microchip Technology Inc.

SI

VIN(t)dt =

∫

0

VRT

RC

RI

where:
VR = Reference Voltage

TSI = Signal Integration Time (Fixed)
TRI = Reference Voltage Integration Time (Variable)

For a constant VIN:

T

VIN = V

6

RI

R

T

SI

ANALOG

INPUT

SIGNAL

+/–

REF

VOLTAGE

INTEGRATOR

INTEGRATE

POLARITY CONTROL

OUTPUT

VARIABLE

FIXED

REFERENCE

SIGNAL

INTEGRATE
TIME

TIME

Figure 2A. Basic Dual Slope Converter

C

INTEGRATOR

–

+

SWITCH

DRIVER

DISPLAY

V
V

© 2001 Microchip Technology Inc. DS21455A

PHASE
CONTROL

≈

V

IN

FULL SCALE

1/2 V

≈

IN

COMPARATOR

–

+

CONTROL

LOGIC

FULL SCALE

CLOCK

COUNTER

3-1/2 Digit A/D Converters

TC7106

TC7106A

TC7107

TC7107A

The dual slope converter accuracy is unrelated to the
integrating resistor and capacitor values as long as they are
stable during a measurement cycle. An inherent benefit is
noise immunity. Noise spikes are integrated or averaged to
zero during the integration periods. Integrating ADCs are
immune to the large conversion errors that plague succes­sive approximation converters in high-noise environments.
Interfering signals with frequency components at multiples
of the averaging period will be attenuated. Integrating ADCs
commonly operate with the signal integration period set to a
multiple of the 50/60Hz power line period. (Figure 2B)

30

20

10

NORMAL MODE REJECTION (dB)

0

0.1/T 1/T 10/T

Figure 2B. Normal-Mode Rejection of Dual Slope Converter

T = MEASUREMENT PERIOD

INPUT FREQUENCY

ANALOG SECTION

In addition to the basic signal integrate and deintegrate
cycles discussed, the circuit incorporates an auto-zero
cycle. This cycle removes buffer amplifier, integrator, and
comparator offset voltage error terms from the conversion.
A true digital zero reading results without adjusting external
potentiometers. A complete conversion consists of three
cycles: an auto-zero, signal-integrate and reference-inte­grate cycle.

Signal Integrate Cycle

When the auto-zero loop is opened, the internal differ­ential inputs connect to V
signal is integrated for a fixed time period. The signal
integration period is 1000 counts. The externally set clock
frequency is divided by four before clocking the internal
counters. The integration time period is:

TSI = x 1000

where: f

= External Clock Frequency

OSC

The differential input voltage must be within the device
common-mode range (1V of either supply) when the con­verter and measured system share the same power supply
common (ground). If the converter and measured system do
not share the same power supply common, V
tied to analog common.

Polarity is determined at the end of the signal integrate
phase. The sign bit is a true polarity indication in that signals
less than 1 LSB are correctly determined. This allows
precision null detection, limited only by device noise and
auto-zero residual offsets.

+

and V

IN

4

f

OSC

–

. The differential input

IN

–

should be

IN

Reference Integrate Cycle

The final phase is reference integrate or de-integrate.

–

V

is internally connected to analog common and V

IN

+

is

IN

connected across the previously charged reference capaci­tor. Circuitry within the chip ensures that the capacitor will be
connected with the correct polarity to cause the integrator
output to return to zero. The time required for the output to
return to zero is proportional to the input signal and is
between 0 and 2000 counts. The digital reading displayed is:

V

1000 x

V

IN

REF

DIGITAL SECTION (TC7106A)

Auto-Zero Cycle

During the auto-zero cycle the differential input signal is
disconnected from the circuit by opening internal analog
gates. The internal nodes are shorted to analog common
(ground) to establish a zero-input condition. Additional ana­log gates close a feedback loop around the integrator and
comparator. This loop permits comparator offset voltage
error compensation. The voltage level established on C
compensates for device offset voltages. The offset error
referred to the input is less than 10µV.

The auto-zero cycle length is 1000 to 3000 counts.

© 2001 Microchip Technology Inc. DS21455A

AZ

The TC7106A (Figure 3) contains all the segment driv­ers necessary to directly drive a 3-1/2 digit liquid crystal
display (LCD). An LCD backplane driver is included. The
backplane frequency is the external clock frequency divided
by 800. For three conversions/second the backplane fre­quency is 60Hz with a 5V nominal amplitude. When a
segment driver is in phase with the backplane signal the
segment is “OFF.” An out of phase segment drive signal
causes the segment to be “ON” or visible. This AC drive
configuration results in negligible DC voltage across each
LCD segment. This insures long LCD display life. The
polarity segment driver is “ON” for negative analog inputs. If

+

V

IN

7

and V

–

are reversed, this indicator will reverse.

IN

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

3-1/2 Digit A/D Converters

+

V

1

BACKPLANE

21

LCD DISPLAY

+

V

OUTPUT

SEGMENT

INT

0.5mA

2mA

C

200

÷

DECODE

7 SEGMENT

DECODE

7 SEGMENT

LCD SEGMENT DRIVERS

7 SEGMENT

INT

V

27333634

DECODE

TO

DIGITAL

SECTION

+

DATA LATCH

–

TENS UNITS

HUNDREDS

THOUSANDS

TO SWITCH DRIVERS

FROM COMPARATOR OUTPUT

37

6.2V

CONTROL LOGIC

÷4

OSC

f

CLOCK

–

TEST

V

26

Ω

500

TH

V

= 1V

INTERNAL DIGITAL GOUND

3

OSC

OSC

C

39

2

OSC

OSC

R

TYPICAL SEGMENT OUTPUT

INTERNAL DIGITAL GROUND

TC7106A

AZ

C

+

V

INT

R

BUFF

V

–

REF

C

–

REF

V

REF

C

+

REF

V

+

REF

C

INTEGRATOR

29

1

28

35

–

–

A/Z

A/Z

10

+

+

µA

COMPARATOR

A/Z

DE

DE

31

+

IN

V

(+)

(–)

INT

LOW

TEMPCO

V

–

A/Z

REF

+

DE (–)

DE (+)

32

– 3.0V

+

V

AZ & DE (±)

30

OMMON

ANALOG

–

26

V

INT

–

IN

V

1

40 38

OSC

© 2001 Microchip Technology Inc.

Figure 3. TC7106A Block Diagram

8

© 2001 Microchip Technology Inc. DS21455A

3-1/2 Digit A/D Converters

TC7106

TC7106A

TC7107

TC7107A

When the TEST pin on the TC7106A is pulled to V+, all
segments are turned “ON.” The display reads –1888. During
this mode the LCD segments have a constant DC voltage
impressed. DO NOT LEAVE THE DISPLAY IN THIS MODE
FOR MORE THAN SEVERAL MINUTES! LCD displays
may be destroyed if operated with DC levels for extended
periods.

The display font and the segment drive assignment are
shown in Figure 4.

DISPLAY FONT

1000's 100's 10's 1's

Figure 4. Display Font and Segment Assignment

In the TC7106A, an internal digital ground is generated
from a 6 volt zener diode and a large P channel source
follower. This supply is made stiff to absorb the large
capacitive currents when the backplane voltage is switched.

DIGITAL SECTION (TC7107A)

Figure 5 shows the TC7107A. It is designed to drive
common anode LEDs. It is identical to the TC7106A except
that the regulated supply and backplane drive have been
eliminated and the segment drive is typically 8mA. The
1000's output (pin 19) sinks current from two LED segments,
and has a 16mA drive capability.

In both devices, the polarity indication is “ON” for nega­tive analog inputs. If V

–

and V

IN

+

are reversed, this indication

IN

can be reversed also, if desired.

The display font is the same as the TC7106A.

System Timing

The oscillator frequency is divided by 4 prior to clocking
the internal decade counters. The three-phase measure­ment cycle takes a total of 4000 counts or 16000 clock
pulses. The 4000 count cycle is independent of input signal
magnitude.

Each phase of the measurement cycle has the following
length:

• Auto-Zero Phase: 1000 to 3000 Counts

(4000 to 12000 Clock Pulses)
For signals less than full-scale, the auto-zero phase is
assigned the unused reference integrate time period.

© 2001 Microchip Technology Inc. DS21455A

• Signal Integrate: 1000 Counts
(4000 Clock Pulses)

This time period is fixed. The integration period is:

1

Where f

TSI = 4000

is the externally set clock frequency.

OSC

[]

f

OSC

• Reference Integrate: 0 to 2000 Counts

(0 to 8000 Clock Pulses)

The TC7106A/7107A are drop-in replacements for the
7106/7107 parts. External component value changes are
not required to benefit from the low drift internal reference.

Clock Circuit

Three clocking methods may be used:

1. An external oscillator connected to pin 40.

2. A crystal between pins 39 and 40.

3. An R-C oscillator using all three pins.

TC7106A
TC7107A

TO

4

÷

COUNTER

EXT
OSC

40

CRYSTAL

RC NETWORK

TO TEST PIN ON TSC7106A
TO GND PIN ON TSC7107A

Figure 6. Clock Circuits

39

38

COMPONENT VALUE SELECTION
Auto-Zero Capacitor – C

The CAZ capacitor size has some influence on system
noise. A 0.47µF capacitor is recommended for 200mV full­scale applications where 1 LSB is 100µV. A 0.047µF capaci­tor is adequate for 2.0V full-scale applications. A mylar
dielectric capacitor is adequate.

Reference Voltage Capacitor – C

The reference voltage used to ramp the integrator
output voltage back to zero during the reference-integrate
cycle is stored on C
when V
voltage exists (V

–

is tied to analog common. If a large common-mode

IN

–

REF

requires 200mV full-scale, increase C
error will be held to less than 1/2 count. A mylar dielectric
capacitor is adequate.

9

. A 0.1µF capacitor is acceptable

REF

≠ analog common) and the application

AZ

REF

to 1.0 µF. Rollover

REF

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

3-1/2 Digit A/D Converters

+

V

1

DIGITAL

21

GROUND

37

TEST

LED DISPLAY

+

V

OUTPUT

SEGMENT

0.5mA

TYPICAL SEGMENT OUTPUT

8mA

INTERNAL DIGITAL GROUND

TC7107A

DECODE

7 SEGMENT

DECODE

7 SEGMENT

LCD SEGMENT DRIVERS

DECODE

7 SEGMENT

TO

DIGITAL

INT

INT

C

V

27333634

AZ

C

+

V

INT

R

BUFF

V

–

REF

C

–

REF

V

REF

C

+

REF

V

INTEGRATOR

29

1

28

35

–

–

DATA LATCH

SECTION

+

–

+

A/Z

+

A/Z

A/Z

TENS UNITS

HUNDREDS

THOUSANDS

TO SWITCH DRIVERS

FROM COMPARATOR OUTPUT

COMPARATOR

LOW

TEMPCO

V

–

DE

(+)

(–)

DE

REF

+

f

CLOCK

– 3.0V

+

V

DE (–)

DE (+)

500Ω

LOGIC CONTROL

DIGITAL GOUND

÷4

OSC

–

26

V

AZ & DE (±)

3

38

OSC

OSC

C

39

2

OSC

OSC

R

1

40

OSC

© 2001 Microchip Technology Inc.

10

+

REF

C

µA

INT

31

+

IN

V

Figure 5. TC7107A Block Diagram

10

A/Z

32

ANALOG

COMMON

INT

30

–

IN

V

© 2001 Microchip Technology Inc. DS21455A

3-1/2 Digit A/D Converters

TC7106

TC7106A

TC7107

TC7107A

Integrating Capacitor – C

C

should be selected to maximize the integrator

INT

INT

output voltage swing without causing output saturation. Due
to the TC7106A/7107A superior temperature coefficient
specification, analog common will normally supply the differ­ential voltage reference. For this case a ±2V full-scale
integrator output swing is satisfactory. For 3 readings/
second (f
different oscillator frequency is used, C

= 48kHz) a 0.22µF value is suggested. If a

OSC

must be changed

INT

in inverse proportion to maintain the nominal ±2 V integrator
swing.

An exact expression for C

V

f

OSC

1

INT

(4000) ( ) ( )

C

=

INT

is:

INT

V

FS

R

INT

Where:
f

= Clock frequency at Pin 38

OSC

VFS = Full-scale input voltage
R

= Integrating resistor

INT

V

= Desired full-scale integrator output swing

INT

C

must have low dielectric absorption to minimize

INT

rollover error. A polypropylene capacitor is recommended.

Integrating Resistor – R

INT

The input buffer amplifier and integrator are designed
with class A output stages. The output stage idling current
is 100µA. The integrator and buffer can supply 20µA drive
currents with negligible linearity errors. R

is chosen to

INT

remain in the output stage linear drive region but not so large
that printed circuit board leakage currents induce errors. For
a 200mV full-scale, R

is 47kΩ. 2.0V full-scale requires

INT

470kΩ.

Component Nominal Full-Scale Voltage

Value

200.0mV 2.000V

C

AZ

R

INT

C

INT

Note:1. f

= 48kHz (3 readings/sec)

OSC

0.47µF 0.047µF
47kΩ 470kΩ

0.22µF 0.22µF

Oscillator Components

R

(Pin 40 to Pin 39) should be 100kΩ. C

OSC

OSC

is

selected using the equation:

0.45

=

RC

is 100pF nominally.

OSC

For f

OSC

Note that f

f

OSC

of 48kHz, C

is divided by four to generate the TC7106A

OSC

internal control clock. The backplane drive signal is derived
by dividing f

OSC

by 800.

To achieve maximum rejection of 60Hz noise pickup,
the signal-integrate period should be a multiple of 60Hz.
Oscillator frequencies of 240kHz, 120kHz, 80kHz, 60kHz,
48kHz, 40kHz, etc. should be selected. For 50 Hz rejection,
oscillator frequencies of 200kHz, 100kHz, 66 2/3kHz, 50kHz,
40kHz, etc. would be suitable. Note that 40kHz (2.5 read­ings/second) will reject both 50Hz and 60Hz.

Reference Voltage Selection

A full-scale reading (2000 counts) requires the input
signal be twice the reference voltage.

Required Full-Scale Voltage* V

200.0mV 100.0mV

2.000V 1.000V

* VFS = 2 V

REF

In some applications a scale factor other than unity may
exist between a transducer output voltage and the required
digital reading. Assume, for example, a pressure transducer
output is 400mV for 2000 lb/in2. Rather than dividing the
input voltage by two the reference voltage should be set to
200mV. This permits the transducer input to be used
directly.

The differential reference can also be used when a
digital zero reading is required when VIN is not equal to zero.
This is common in temperature measuring instrumentation.
A compensating offset voltage can be applied between
analog common and V
nected between V

–

. The transducer output is con-

IN

+

and analog common.

IN

The internal voltage reference potential available at
analog common will normally be used to supply the convert­er's reference. This potential is stable whenever the supply
potential is greater than approximately 7V. In applications
where an externally-generated reference voltage is desired,
refer to Figure 7.

REF

© 2001 Microchip Technology Inc. DS21455A

11

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

3-1/2 Digit A/D Converters

+

+

V

+

V

REF
–

V

REF

TC7106A
TC7107A

(a) (b)

V

6.8V
ZENER

I

Z

Figure 7. External Reference

+

V

TC7106A
TC7107A

+

V

REF

–

V

REF

COMMON

20k

+

V

6.8kΩ

Ω

TC04

1.2V
REF

Device Pin Functional Description
Differential Signal Inputs

+

(V

(Pin 31), V

IN

The TC7106A/7017A is designed with true differential
inputs and accepts input signals within the input stage
common mode voltage range (VCM). The typical range is V
–1.0 to V– +1 V. Common-mode voltages are removed from
the system when the TC7106A/TC7107A operates from a
battery or floating power source (isolated from measured
system) and V
See Figure 8.

In systems where common-mode voltages exist, the
86dB common-mode rejection ratio minimizes error. Com­mon-mode voltages do, however, affect the integrator out­put level. Integrator output saturation must be prevented. A
worst-case condition exists if a large positive VCM exists in
conjunction with a full-scale negative differential signal. The
negative signal drives the integrator output positive along
with VCM (Figure 9). For such applications the integrator
output swing can be reduced below the recommended 2.0V
full-scale swing. The integrator output will swing within 0.3V
of V+ or V– without increasing linearity errors.

–

(Pin 30))

IN

–

is connected to analog common (V

IN

COM

INPUT

+

V

IN

–

V

CM

Figure 9. Common-Mode Voltage Reduces Available Integrator

Differential Reference

+

(V

(Pin 36), V

REF

BUFFER

+

–

Where:

Swing. (V

R

I

V

=

I

RI C

INTEGRATION TIMET

==

I

C

INTEGRATION CAPACITOR

=

I

=

INTEGRATION RESISTOR

R

I

≠ VIN)

COM

–

(Pin 35))

REF

C

I

–

+

INTEGRATOR

T

I

V

–

[

CMVIN

I

The reference voltage can be generated anywhere

within the V+ to V– power supply range.

To prevent rollover errors from being induced by large

common-mode voltages, C

+

should be large compared to

REF

stray node capacitance.

The TC7106A/TC7107A circuits have a significantly
lower analog common temperature coefficient. This gives a
very stable voltage suitable for use as a reference. The

):

temperature coefficient of analog common is 20ppm/°C
typically.

[

V

I

4000

f

OSC

© 2001 Microchip Technology Inc.

SEGMENT

DRIVE

MEASURED

SYSTEM
+

V

–

V

GND

+

–

V

V

GND

POWER

SOURCE

Figure 8. Common-Mode Voltage Removed in Battery Operation with V

V

BUF

V+IN

V–IN

ANALOG
COMMON

12

V

C

–

REF

AZVINT

TC7106A

+

V

REF

+

V

+

9V

LCD DISPLAY

BPPOL

OSC

1

OSC

3

OSC

2

–

V

–

= Analog Common

IN

© 2001 Microchip Technology Inc. DS21455A

3-1/2 Digit A/D Converters

TC7106

TC7106A

TC7107

TC7107A

Analog Common (Pin 32)

The analog common pin is set at a voltage potential
approximately 3.0V below V+. The potential is guaranteed
to be between 2.7V and 3.35 V below V+. Analog common
is tied internally to the N channel FET capable of sinking
20mA. This FET will hold the common line at 3.0V should an
external load attempt to pull the common line toward V+.
Analog common source current is limited to 10µA. Analog
common is therefore easily pulled to a more negative
voltage (i.e., below V+ – 3.0V).

The TC7106A connects the internal V
to analog common during the auto-zero cycle. During the
reference-integrate phase, V
mon. If V

–

is not externally connected to analog common,

IN

–

is connected to analog com-

IN

+

and V

IN

–

inputs

IN

a common-mode voltage exists. This is rejected by the
converter's 86dB common-mode rejection ratio. In battery
operation, analog common and V
removing common-mode voltage concerns. In systems where

–

V

is connected to the power supply ground or to a given

IN

voltage, analog common should be connected to V

–

are usually connected,

IN

–

.

IN

The analog common pin serves to set the analog section
reference or common point. The TC7106A is specifically
designed to operate from a battery or in any measurement
system where input signals are not referenced (float) with
respect to the TC7106A power source. The analog common
potential of V+ – 3.0V gives a 6 V end of battery life voltage.
The common potential has a 0.001%/% voltage coefficient
and a 15 Ω output impedance.

With sufficiently high total supply voltage (V+ – V
> 7.0V) analog common is a very stable potential with
excellent temperature stability—typically 20ppm/°C. This
potential can be used to generate the reference voltage. An
external voltage reference will be unnecessary in most
cases because of the 50ppm/°C maximum temperature
coefficient. See Internal Voltage Reference discussion.

Test (Pin 37)

The TEST pin potential is 5V less than V+. TEST may be
used as the negative power supply connection for external
CMOS logic. The TEST pin is tied to the internally generated
negative logic supply (Internal Logic Ground) through a
500Ω resistor in the TC7106A. The TEST pin load should be
no more than 1mA .

If TEST is pulled to V+ all segments plus the minus sign
will be activated. Do not operate in this mode for more than
several minutes with the TC7106A. With TEST = V+ the LCD
segments are impressed with a DC voltage which will
destroy the LCD.

The TEST pin will sink about 10mA when pulled to V+.

Internal Voltage Reference Stability

The analog common voltage temperature stability has
been significantly improved (Figure 10). The “A” version of
the industry standard circuits allow users to upgrade old
systems and design new systems without external voltage
references. External R and C values do not need to be
changed. Figure 11 shows analog common supplying the
necessary voltage reference for the TC7106A/TC7107A.

200
180
160
140
120
100

80
60
40

TEMPERATURE COEFFICIENT (ppm/°C)

20

Figure 10. Analog Common Temperature Coefficient

–

Figure 11. Internal Voltage Reference Connection

0

NO
MAXIMUM
SPECIFIED

MAXIMUM

LIMIT

TYPICAL

7106A

–

V

TC7106A
TC7107A

SET V

TC

+

V

REF

–

V

REF

ANALOG

COMMON

= 1/2 V

REF

NO MAXIMUM

SPECIFIED

TYPICAL

ICL7106

1

+

V

36

V

REF

35
32

FULL SCALE

NO MAXIMUM

SPECIFIED

TYPICAL

ICL7136

24kΩ

1kΩ

© 2001 Microchip Technology Inc. DS21455A

13

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

3-1/2 Digit A/D Converters

POWER SUPPLIES

The TC7107A is designed to work from ±5V supplies.
However, if a negative supply is not available, it can be
generated from the clock output with two diodes, two capaci­tors, and an inexpensive IC. (Figure 12)

In selected applications a negative supply is not re­quired. The conditions to use a single +5V supply are:

• The input signal can be referenced to the center of the

common-mode range of the converter.

• The signal is less than ±1.5V.

• An external reference is used.

The TSC7660 DC to DC converter may be used to
generate – 5 V from +5 V (Figure 13).

+

V

CD4009

+

V

OSC

1

OSC
OSC

TC7107A

GND

–

V

2
3

0.047
µF

1N914

10

µF

1N914

+

–

TC7107 Power Dissipation Reduction

The TC7107A sinks the LED display current and this
causes heat to build up in the IC package. If the internal
voltage reference is used, the changing chip temperature
can cause the display to change reading. By reducing the
LED common anode voltage the TC7107A package power
dissipation is reduced.

Figure 14 is a photograph of a curve-tracer display
showing the relationship between output current and output
voltage for a typical TC7107CPL. Since a typical LED has

1.8 volts across it at 7mA, and its common anode is con­nected to +5V, the TC7107A output is at 3.2V (point A on
Figure 13). Maximum power dissipation is 8.1mA x 3.2V x
24 segments = 622mW.

Notice, however, that once the TC7107A output voltage
is above two volts, the LED current is essentially constant as
output voltage increases. Reducing the output voltage by

0.7V (point B in Figure 14) results in 7.7mA of LED current,
only a 5 percent reduction. Maximum power dissipation is
only 7.7mA x 2.5 V x 24 = 462mW, a reduction of 26%. An
output voltage reduction of 1 volt (point C) reduces LED
current by 10% (7.3mA) but power dissipation by 38%!
(7.3mA x 2.2V x 24 = 385mW).

V– = –3.3V

Figure 12. Generating Negative Supply From +5 V

+5 V

1
+

36

+

V

V

REF

35

–

V

REF

32

COM

31

+

V

IN

30

–

V

IN

21

–

GND

V

26

10µF

LED
DRIVE

TC7107A

8

2

+

TC7660

4

3

(–5 V)

5

+

10µF

Figure 14. TC7107A Output Current vs Output Voltage

Reduced power dissipation is very easy to obtain.
Figure 15 shows two ways: either a 5.1 ohm, 1/4 watt resistor

V

IN

or a 1 Amp diode placed in series with the display (but not in
series with the TC7107A). The resistor will reduce the
TC7107A output voltage, when all 24 segments are “ON,” to
point “C” of Figure 14. When segments turn off, the output
voltage will increase. The diode, on the other hand, will result
in a relatively steady output voltage, around point “B.”

Figure 13. Negative Power Supply Generation with TC7660

© 2001 Microchip Technology Inc.

14

© 2001 Microchip Technology Inc. DS21455A

3-1/2 Digit A/D Converters

TC7106

TC7106A

TC7107

TC7107A

In addition to limiting maximum power dissipation, the
resistor reduces the change in power dissipation as the
display changes. This effect is caused by the fact that, as
fewer segments are “ON,” each “ON” output drops more
voltage and current. For the best case of six segments (a
“111” display) to worst case (a “1888” display) the resistor
will change about 230mW, while a circuit without the resistor
will change about 470mW. Therefore, the resistor will re­duce the effect of display dissipation on reference voltage
drift by about 50%.

The change in LED brightness caused by the resistor is
almost unnoticeable as more segments turn off. If display
brightness remaining steady is very important to the de­signer, a diode may be used instead of the resistor.

0.47
µF

0.22
µF

4

–5V

150Ω

DISPLAY

20101

+5V

24kΩ

1kΩ

100

TP5

100

kΩ

40 TP

pF

TP2

TP1

0.1
µF

+

Ω

1 M

TP3

TC7107A

IN

–

0.01
µF

47
kΩ

30 21

APPLICATIONS INFORMATION

Liquid Crystal Display Sources

Several LCD manufacturers supply standard LCD dis­plays to interface with the TC7106A 3-1/2 digit analog-to­digital converter.

Manufacturer Address/Phone Part Numbers

Crystaloid 5282 Hudson Dr. C5335, H5535,
Electronics Hudson, OH 44236 T5135, SX440

216/655-2429

AND 720 Palomar Ave. FE 0201,0701

Sunnyvale, CA 94086 FE 0203, 2201
408/523-8200 FE 0501

Epson 3415 Kashikawa St. LD-B709BZ

Torrance, CA 90505 LD-H7992AZ
213/534-0360

Hamlin, Inc. 612 E. Lake St. 3902, 3933, 3903

Lake Mills, WI 53551
414/648-2361

Note: 1. Contact LCD manufacturer for full product listing/specifications.

Light Emitting Diode Display Sources

Several LED manufacturers supply seven segment
digits with and without decimal point annunciators for the
TC7107A.

1

5.1Ω 1/4W

DISPLAY

1N4001

Figure 15. Diode or Resistor Limits Package Power Dissipation

© 2001 Microchip Technology Inc. DS21455A

Manufacturer Address Display Type

Hewlett-Packard 640 Page Mill Rd. LED
Components Palo Alto, CA 94304

AND 720 Palomar Ave. LED

Sunnyvale, CA 94086

15

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

3-1/2 Digit A/D Converters

Decimal Point and Annunciator Drive

The TEST pin is connected to the internally-generated
digital logic supply ground through a 500 Ω resistor. The
TEST pin may be used as the negative supply for external
CMOS gate segment drivers. LCD display annunciators for
decimal points, low battery indication, or function indication
may be added without adding an additional supply. No more
than 1mA should be supplied by the TEST pin: its potential
is approximately 5V below V+.

+

+

V

TC7106A

TEST

BP

21

37

V

4049

TO LCD
DECIMAL
POINT

GND

TO LCD
BACK­PLANE

Ratiometric Resistance Measurements

The true differential input and differential reference
make ratiometric reading possible. Typically in a 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
developed across the unknown is applied to the input and
the voltage across the known resistor is applied to the
reference input. If the unknown equals the standard, the
display will read 1000. The displayed reading can be deter­mined from the following expression:

Displayed Reading = x 1000

The display will overrange for R Unknown ≥ 2 x R
standard.

R

STANDARD

R Unknown

R Standard

+

V

V

REF

–

V

REF

+

+

V

+

V

BP

TC7106A

TEST

Figure 16. Decimal Point Drive Using TEST as Logic Ground

DECIMAL

POINT

SELECT

4030

GND

TO LCD
DECIMAL
POINTS

+

TC7106A

V

IN

R

UNKNOWN

–

V

IN

ANALOG
COMMON

Figure 17. Low Parts Count Ratiometric Resistance

Measurement

LCD DISPLAY

© 2001 Microchip Technology Inc.

16

© 2001 Microchip Technology Inc. DS21455A

3-1/2 Digit A/D Converters

TC7106A

V

+

V

–

V

IN

–

V

IN

+

V

REF

+

V

REF

–

COMMON

5.6kΩ 160kΩ

R

2

20kΩ

1N914

9V

R

1

20kΩ

+

R

3

0.7%/°C
PTC

V

IN

900kΩ

90kΩ

10kΩ

9MΩ

200mV

2 V

20 V

200 V

COM

C1 = 3–10pF VARIABLE,
C2 = 132pF VARIABLE

IN4148

0.02

47kΩ

1 W

10%

µF

10kΩ

1MΩ

1MΩ

6.8µF

20kW

10%

1µF

–

+

TC7106

TC7106A

TC7107

TC7107A

9V

+

+

–

1
2
3
4

AD636
5
6
7

14
13

12
11
10

24kΩ

1kΩ

9

1MΩ 10%

8

2.2µF

0.01
µF

1

36

35
32
31

30
26

+

V

+

V

REF

–

V

REF

ANALOG
COMMON

+

V

IN

–

V

IN

–

V

26

–

V

TC7106A

27

29

28

40

38
39

160kΩ 300kΩ 300kΩ

1N4148
SENSOR

50kΩ

R

2

R

50kΩ

1

Figure 19. Temperature Sensor

V

–

V

IN

+

V

IN

+

V

REF

–

V

REF

COMMON

Figure 18. 3 1/2 Digit True RMS AC DMM

+

9V

+

–

V

TC7106A

VFS = 2V

Figure 20. Positive Temperature Coefficient Resistor

Temperature Sensor

SEG
DRIVE

LCD DISPLAY

BP

© 2001 Microchip Technology Inc. DS21455A

17

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

3-1/2 Digit A/D Converters

9V

TC7106A

TO PIN 1

40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21

+

V

REF02

GND

100k

100pF

0.1µF

0.47µF

0.22µF

TO DISPLAY

TO BACKPLANE

2 1

V

TEMP

4 26

OUT

ADJ

CONSTANT 5 V

6

5

3

NC

TEMPERATURE
DEPENDENT
OUTPUT

51kΩ 5.1kΩ

R

4

1.3k

R

5

2

3

–

+

TC911

8

1

4

R

V

OUT =

1.86V @
25°C

R

+

V

+

V

REF

50kΩ

2

50kΩ

1

TC7106A

–

V

REF

VFS = 2.00V

–

V

IN

+

V

IN

COMMON

–

V

Figure 21. Integrated Circuit Temperature Sensor

TO PIN 1

SET V

Ω

1 k

REF

Ω

47k

= 100mV

0.01µF

Ω

22k

1M

0.1

100k

100pF

µ

F

SET V

Ω

1k

40
39
38
37
36
35

Ω

Ω

+

IN

+

–

TC7107A

9V

–

34
33
32
31
30
29
28
27
26
25
24
23
22
21

0.47µF

0.22µF

TO DISPLAY

Ω

47k

= 100mV

REF

0.01µF

Ω

22k

1M

Ω

Ω

+5V

+

IN

–

–5V

Figure 22. TC7106A Using the Internal Reference: 200mV Full-

Scale, 3 Readings-per-second (RPS).

© 2001 Microchip Technology Inc.

Figure 23. TC7107A Internal Reference (200mV Full-Scale,

3RPS, V

18

–

Tied to GND for Single Ended Inputs).

IN

© 2001 Microchip Technology Inc. DS21455A

3-1/2 Digit A/D Converters

100pF

0.47µF
47k

Ω

TO DISPLAY

0.1

µF

1 k

Ω

Ω

V

SET V

REF

= 100mV

+

10k

10k

Ω

1.2V

0.01µF

–

IN

1M

Ω

+

100k

Ω

0.22µF

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

TC04

TC7107A

TO PIN 1

+

O/R

U/R

CD4023
OR 74C10

TO

LOGIC

V

CC

V

CD4077

1

O/R = OVERRANGE
U/R = UNDERRANGE

TC7106A

TC7106

TC7106A

TC7107

TC7107A

40

TO

LOGIC

GND

–

V

2120

TC7106A
TC7107A

TO PIN 1

40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
23
22
21

100k

100pF

0.1µF

0.047µF

0.22µF

TO DISPLAY

Ω

SET V

25k

470k

Ω

0.01µF

REF

Ω

24k

1M

= 1V

Ω

Ω

+

V

+

IN

–

–

V

Figure 24. Circuit for Developing Underrange and Overrange

Signals from TC7106A Outputs.

TO PIN 1

40
39
38
37
36
35
34
33
32
31

TC7107A

Figure 26. TC7107A With a 1.2V External Band-Gap Reference.

© 2001 Microchip Technology Inc. DS21455A

30
29
28
27
26
25
24
23
22
21

–

(V

IN

Tied to Common.)

100k

100pF

µF

0.1

0.47µF

0.22µF

TO DISPLAY

Ω

1k

Ω

0.01µF

47k

SET V

10k

1.2V

Ω

REF

Ω

= 100mV

1M

10k

Ω

TC04

Ω

Figure 25. TC7106A/TC7107A: Recommended Component

Values for 2.00V Full-Scale

+

V

+

IN

–

–

V

Figure 27. TC7107A Operated from Single +5V Supply. An

External Reference Must Be Used in This Application.

19

TC7106/6A/7/7A-7 11/4/96

TC7106

(

)

(

)

TC7106A
TC7107
TC7107A

PACKAGE DIMENSIONS

3-1/2 Digit A/D Converters

40-Pin CerDIP

PIN 1

.540 (13.72)
.510 (12.95)

.210 (5.33)
.170 (4.32)

.200 (5.08)
.125 (3.18)

.098 (2.49) MAX.

.110 (2.79)
.090 (2.29)

2.070 (52.58)

2.030 (51.56)

.065 (1.65)
.045 (1.14)

.020 (0.51)
.016 (0.41)

.030 (0.76) MIN.

.060 (1.52)
.020 (0.51)

.150 (3.81)

MIN.

40-Pin PDIP

PIN 1

.555 (14.10)
.530 (13.46)

.015 (0.38)
.008 (0.20)

.620 (15.75)
.590 (15.00)

3° MIN.

.700 (17.78)
.620 (15.75)

.200 (5.08)
.140 (3.56)

.150 (3.81)
.115 (2.92)

.110 (2.79)
.090 (2.29)

© 2001 Microchip Technology Inc.

2.065 (52.45)

2.027 (51.49)

.070 (1.78)
.045

1.14

.022 (0.56)
.015

0.38

.040 (1.02)
.020 (0.51)

20

.015 (0.38)
.008 (0.20)

.610 (15.49)
.590 (14.99)

3° MIN.

.700 (17.78)
.610 (15.50)

Dimensions: inches (mm)

© 2001 Microchip Technology Inc. DS21455A

3-1/2 Digit A/D Converters

PACKAGE DIMENSIONS (Cont.)

TC7106

TC7106A

TC7107

TC7107A

44-Pin PLCC

PIN 1

.695 (17.65)
.685 (17.40)

.656 (16.66)
.650 (16.51)

.656 (16.66)
.650 (16.51)

.695 (17.65)
.685 (17.40)

.050 (1.27) TYP.

44-Pin PQFP

.021 (0.53)
.013 (0.33)

.630 (16.00)
.591 (15.00)

.032 (0.81)
.026 (0.66)

.020 (0.51) MIN.

.120 (3.05)
.090 (2.29)

.180 (4.57)
.165 (4.19)

7° MAX.

.018 (0.45)
.012 (0.30)

.031 (0.80) TYP.

© 2001 Microchip Technology Inc. DS21455A

PIN 1

.398 (10.10)

.390 (9.90)

.557 (14.15)
.537 (13.65)

.398 (10.10)

.390 (9.90)

.557 (14.15)
.537 (13.65)

21

.009 (0.23)
.005 (0.13)

.096 (2.45) MAX.

.041 (1.03)
.026 (0.65)

.010 (0.25) TYP.
.083 (2.10)

.075 (1.90)

Dimensions: inches (mm)

TC7106/6A/7/7A-7 11/4/96

TC7106
TC7106A
TC7107
TC7107A

W

ORLDWIDE SALES AND SERVICE

3-1/2 Digit A/D Converters

AMERICAS

Corporate Office

2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: [phone] Fax: [phone]
Technical Support: 480-792-7627
Web Address: http://www.microchip.com

Rocky Mountain

2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: [phone] Fax: [phone]

Atlanta

500 Sugar Mill Road, Suite 200B
Atlanta, GA 30350
Tel: [phone] Fax: [phone]

Austin

Analog Product Sales
8303 MoPac Expressway North
Suite A-201
Austin, TX 78759
Tel: [phone] Fax: [phone]

Boston

2 Lan Drive, Suite 120
Westford, MA 01886
Tel: [phone] Fax: [phone]

Boston

Analog Product Sales
Unit A-8-1 Millbrook Tarry Condominium
97 Lowell Road
Concord, MA 01742
Tel: [phone] Fax: [phone]

Chicago

333 Pierce Road, Suite 180
Itasca, IL 60143
Tel: [phone] Fax: [phone]

Dallas

4570 Westgrove Drive, Suite 160
Addison, TX 75001
Tel: [phone] Fax: [phone]

Dayton

Two Prestige Place, Suite 130
Miamisburg, OH 45342
Tel: [phone] Fax: [phone]

Detroit

Tri-Atria Office Building
32255 Northwestern Highway, Suite 190
Farmington Hills, MI 48334
Tel: [phone] Fax: [phone]

Los Angele s

18201 Von Karman, Suite 1090
Irvine, CA 92612
Tel: [phone] Fax: [phone]

Mountain View

Analog Product Sales
1300 Terra Bella Avenue
Mountain View, CA 94043-1836
Tel: [phone] Fax: [phone]

All rights reserved. © 2001 Microchip Technology Incorporated. Printed in the USA. 1/01 Printed on recycled paper.

Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by
updates. It is your re sponsib ility to en sure that your applicati on mee ts with your specifica tions. No repr esentation or warra nty is given and no liability is
assumed by Micro chip Technology Incorporated with respe ct to the a ccuracy or use of such infor mati on, or infrin gemen t of patents or o th er int ell ec tua l
property rights arising from such use or otherwise. Use of Microchipís products as critical components in life support systems is not authorized except with
express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, except as maybe explicitly expressed herein, under any intellec­tual property rights. The Mi crochip logo and name are registered trad emarks of Microchip Technology Inc. in the U.S.A. and other countries. All rights
reserved. All other trademarks mentioned herein are the property of their respective companies.

New York

150 Motor Parkway, Suite 202
Hauppauge, NY 11788
Tel: [phone] Fax: [phone]

San Jose

Microchip Technology Inc.
2107 North First Street, Suite 590
San Jose, CA 95131
Tel: [phone] Fax: [phone]

Toronto

6285 Northam Drive, Suite 108
Mississa uga, Ontario L4V 1X5, Canada
Tel: [phone] Fax: [phone]

ASIA/PACIFIC

China - Beijing

Microchip Technology Beijing Office
Unit 915
New China Hong Kong Manhattan Bldg.
No. 6 Chaoyangmen Beidajie
Beijing, 100027, No. China
Tel: [phone] Fax: [phone]

China - Shanghai

Microchip Technology Shanghai Office
Room 701, Bldg. B
Far East Int ernational Plaza
No. 317 Xian Xia Road
Shanghai, 200051
Tel: [phone] Fax: [phone]

Hong Kong

Microchip Asia Pacific
RM 2101, Tower 2, Metroplaza
223 Hing Fong Road
Kwai Fong, N.T., Hong Kong
Tel: [phone] Fax: [phone]

India

Microchip Technology Inc.
India Liaison Office
Divyasree Chambers
1 Floor, Wing A (A3/A4)
No. 11, OíShaugnessey Road
Bangalore, 560 025, India
Tel: [phone] Fax: [phone]

Japan

Microchip Technology Intl. Inc.
Benex S-1 6F
3-18-20, Shinyokohama
Kohoku-Ku, Yokohama-shi
Kanagawa, 222-0033, Japan
Tel: [phone] Fax: [phone]

Korea

Microchip Technology Korea
168-1, Youngbo Bldg. 3 Floor
Samsung-Dong, Kangnam-Ku
Seoul, Korea
Tel: [phone] Fax: [phone]

ASIA/PACIFIC

(continued)

Singapore

Microchip Technology Singapore Pte Ltd.
200 Middle Road
#07-02 Prime Centre
Singapore, 188980
Tel: [phone] Fax: [phone]

Taiwan

Microchip Technology Taiwan
11F-3, N o. 20 7
Tung Hua North Road
Taipei, 105, Taiwan
Tel: [phone] Fax: [phone]

EUROPE

Australia

Microchip Technology Australia Pty Ltd
Suite 22, 41 Rawson Street
Epping 2121, NSW
Australia
Tel: [phone] Fax: [phone]

Denmark

Microchip Technology Denmark ApS
Regus Business Centre
Lautrup hoj 1-3
Ballerup DK-2750 Denmark
Tel: [phone] Fax: [phone]

France

Arizona Microchip Technology SARL
Parc díActivite du Moulin de Massy
43 Rue du Saule Trapu
Batiment A - ler Etage
91300 Massy, France
Tel: [phone] Fax: [phone]

Germany

Arizona Microchip Technology GmbH
Gustav-Heinemann Ring 125
D-81739 Munich, Germany
Tel: [phone] Fax: [phone]

Germany

Analog Product Sales
Lochhamer Strasse 13
D-82152 Martinsried, Germany
Tel: [phone] Fax: [phone]

Italy

Arizona Microchip Technology SRL
Centro Direzionale Colleoni
Palazzo Taurus 1 V. Le Colleoni 1
20041 Agrate Brianza
Milan, Italy
Tel: [phone] Fax: [phone]

United Kingdom

Arizona Microchip Technology Ltd.
505 Eskdale Road
Winnersh Triangle
Wokingham
Berkshire, England RG41 5TU
Tel: [phone] Fax: [phone]

01/09/01

© 2001 Microchip Technology Inc.

22

© 2001 Microchip Technology Inc. DS21455A