TelCom Semiconductor Inc TC7136RCPL, TC7136RCLW, TC7136RCKW, TC7136CPL, TC7136ARCPL Datasheet

3-247

TELCOM SEMICONDUCTOR, INC.

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TC7136

TC7136A

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

* "A" parts have an improved reference TC

Package Code (see below):

TYPICAL APPLICATIONS

■ Thermometry

■ Bridge Readouts: Strain Gauges, Load Cells, Null

Detectors

■ Digital Meters: Voltage/Current/Ohms/Power, pH

■ Digital Scales, Process Monitors

■ Portable Instrumentation

ORDERING INFORMATION
PART CODE TC7136X X XXX

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

40-Pin Plastic DIP

44-Pin Plastic Quad Flat

Package Formed Leads

44-Pin Plastic Chip

Carrier PLCC

V

REF

+

TC7136

TC7136A

33

34

240 kΩ

10 kΩ

31

29

39 38 40

V

REF

–

0.47
µF

0.1 µF

V

–

1

OSC

3

OSC

2

OSC

TO ANALOG COMMON
(PIN 32)

1 CONVERSION/SEC

C

OSC

560 kΩ

180 kΩ

0.15 µF

0.01 µF

ANALOG

INPUT

+

–

C

REF

–

C

REF

+

V

IN

+

V

IN

–

ANALOG
COMMON

V

INT

V

BUFF

C

AZ

20
21
1

SEGMENT
DRIVE

9–19

22–25

POL

BP

V

+

MINUS SIGN

BACKPLANE

28

50 pF

LCD

1 MΩ

27

30

32

35

36

9V

+

R

OSC

26

TYPICAL OPERATING CIRCUIT

AVAILABLE PACKAGES

LOW POWER, 3-1/2 DIGIT ANALOG-T O-DIGITAL CONVERTERS

FEATURES

■ Fast Overrange Recovery, Guaranteed First

Reading Accuracy

■ Low Temperature Drift Internal Reference

TC7136 ....................................... 70 ppm/°C Typ

TC7136A.....................................35 ppm/°C Typ

■ Guaranteed Zero Reading With Zero Input

■ Low Noise....................................................15 µV

P-P

■ High Resolution .............................................. 0.05%

■ Low Input Leakage Current ......................1 pA Typ

10 pA Max

■ Precision Null Detectors With True Polarity at

Zero

■ High-Impedance Differential Input

■ Convenient 9V Battery Operation With

Low Power Dissipation ........................500 µW Typ

900 µW Max

GENERAL DESCRIPTION

The TC7136 and TC7136A are low-power, 3-1/2 digit
with liquid crystal display (LCD) drivers with analog-to­digital converters. These devices incorporate an "integra­tor output zero" phase which guarantees overrange
recovery. The performance of existing TC7126, TC7126A
and ICL7126-based systems may be upgraded with minor
changes to external, passive components.

The TC7136A has an improved internal zener refer­ence voltage circuit which maintains the analog common
temperature drift to 35 ppm/°C (typical) and 75 ppm/°C
(maximum). This represents an improvement of two to four
times over similar 3-1/2 digit converters. The costly, space­consuming external reference source may be removed.

The TC7136/A limits linearity error to less than 1 count
on 200 mV or 2V full-scale ranges. Roll-over error — the
difference in readings for equal magnitude but opposite
polarity input signals — is below ±1 count. High-impedance
differential inputs offer 1 pA leakage currents and a 1012Ω
input impedance. The differential reference input allows
ratiometric measurements for ohms or bridge transducer
measurements. The 15 µV

P-P

noise performance guaran­tees a "rock solid" reading. The auto-zero cycle guarantees
a zero display readout for a 0V input.

TC7136-6 10/18/96

3-248

TELCOM SEMICONDUCTOR, INC.

ABSOLUTE MAXIMUM RATINGS*

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 (TA ≤ 70°C) (Note 2)

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

Plastic Quad Flat Package ...............................1.00W

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

Operating Temperature Range

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

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

Storage Temperature Range .................–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: V

S

= 9V, f

CLK

= 16 kHz, and TA = +25°C, unless otherwise noted.

Symbol Parameter Test Conditions Min Typ Max Unit

Input

Zero Input Reading VIN = 0V – 000.0 ±000.0 +000.0 Digital

Full Scale = 200 mV Reading
Zero Reading Drift VIN = 0V, 0°C ≤ TA ≤ +70°C — 0.2 1 µV/°C
Ratiometric Reading VIN = V

REF

, V

REF

= 100 mV 999 999/1000 1000 Digital

Reading

NL Nonlinearity Error Full Scale = 200 mV or 2V – 1 ±0.2 1 Count

Max Deviation From Best

Straight Line
Roll-Over Error –VIN = +VIN ≈ 200 mV – 1 ±0.2 1 Count

e

N

Noise VIN = 0V, Full Scale = 200 mV — 15 — µV

P-P

I

L

Input Leakage Current VIN = 0V — 1 10 pA

CMRR Common-Mode Rejection VCM = ±1V, VIN = 0V, — 50 — µV/V

Ratio Full Scale = 200 mV
Scale Factor Temperature VIN = 199 mV, 0°C ≤ TA ≤ +70°C — 1 5 ppm/°C

Coefficient Ext Ref Temp Coeff = 0 ppm/°C

Analog Common

V

CTC

Analog Common 250 kΩ Between Common and V

+

Temperature Coefficient 0°C ≤ TA ≤ +70°C TC7136A — 35 75 ppm/°C

"C" Commercial Temp TC7136 — 70 150 ppm/°C

Range Devices

– 25°C ≤ T

A

≤ +85°C TC7136A — 35 100 ppm/°C
"I" Industrial Temp TC7136 — 70 150 ppm/°C
Range Devices

V

C

Analog Common Voltage 250 kW Between Common and V

+

2.7 3.05 3.35 V

LCD Drive

V

SD

LCD Segment Drive Voltage V+ to V– = 9V 4 5 6 V

P-P

V

BD

LCD Backplane Drive Voltage V+ to V– = 9V 4 5 6 V

P-P

Power Supply

I

S

Power Supply Current VIN = 0V, V+ to V– = 9V (Note 6) — 70 100 µA

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

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

3. Refer to "Differential Input" discussion.

4. Backplane drive is in-phase with segment drive for "OFF" segment and 180° out-of-phase for "ON" segment. Frequency is 20 times
conversion rate. Average DC component is less than 50 mV.

5. See "Typical Operating Circuit".

6. A 48 kHz oscillator increases current by 20 µA (typical). Common current not included.

TC7136
TC7136A

LOW POWER, 3-1/2 DIGIT

ANALOG-TO-DIGITAL CONVERTERS

3-249

TELCOM SEMICONDUCTOR, INC.

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PIN CONFIGURATIONS

TC7136CPL

TC7136ACPL

(PDIP)

1
2
3
4

OSC

1

5
6
7
8

9
10
11
12

TEST
V

ANALOG
COMMON

C

AZ

V

+

D

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

2

C

2

B

2

A

2

F

2

E

2

D

3

B

3

F

3

E

3

AB

4

10's

100's

1000's

100's

OSC

2

OSC

3

+
REF

V

–
REF

C

+
REF

C

–
REF

V

+
IN

V

–

IN

V

BUFF

V

INT

V

–

G
C
A
G
BP

(BACKPLANE)

POL

(MINUS SIGN)

3

3

3

2

TC7136RCPL

TC7136ARCPL

(Reversed)

PDIP

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 PIN

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
(MINUS SIGN)

D

1

C

1

B

1

A

1

F

1

G

1

E

1

1's

10's

OSC

TEST

V

ANALOG

COMMON

C

AZ

OSC

2

OSC

+
REF

V

–
REF

C

+

REF

C

–
REF

V

+
IN

V

–
IN

V

BUFF

V

INT

V

–

G
C
A
G
BP

(BACKPLANE)

3

3

3

2

3

1

NC = NO INTERNAL CONNECTION

27

28

29

30

31

32

33

7

4

3

2

1

NC

TC7136CKW

TC7136ACKW

(PQFP)

12 13 14 15 17 18

G

44 43 42 41 39 3840

REF HI

COM

16

37AZ36

BUFF35INT34V

19 20 21 22

D

26

8

+

25

9

24

10

23

11

IN HI

5
6

C

OSC

TEST

NC

NC

V

3

3

D2C2B2A

2F2E2

NC

OSC

2

OSC

1

REF LO

REFCREF

C

IN LO

–

2

3

A

3

G

3

BP
POL

AB

4

E

3

F

3

B

3

33

34

35

36

37

38

39

13

10

9

8

7

COMMON

REF LO

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3

AB

4

POL

NC

BP

IN HI

NC

IN LO

B

6543 1442

A

OSC

22

43

OSC42OSC41TEST40REF HI

25 26 27 28

F

E

G

A

C

G

3214

AZ

2

3115

BUFF

2

3016

INT

E

2917

D

NC

11

12

NC

C

D

3

2

F

A

2

2

2

B

3

3

3

3

3

2

TC7136CLW

TC7136ACLW

(PLCC)

1

2

3

V

–

1B1C1D1V+

F

1

G

1

E

1

D

1

C

1

B

1

A

1F1G1E1

+

–

REF

C

REF

C

+

–

LOW POWER, 3-1/2 DIGIT
ANALOG-TO-DIGITAL CONVERTERS

TC7136

TC7136A

3-250

TELCOM SEMICONDUCTOR, INC.

TC7136
TC7136A

LOW POWER, 3-1/2 DIGIT

ANALOG-TO-DIGITAL CONVERTERS

COMMON

TC7136/A PIN DESCRIPTION

Pin No.

40-Pin PDIP

Normal (Reverse) Name Description

1 (40) V

+

Positive supply voltage.

2 (39) D

1

Activates the D section of the units display.

3 (38) C

1

Activates the C section of the units display.

4 (37) B

1

Activates the B section of the units display.

5 (36) A

1

Activates the A section of the units display.

6 (35) F

1

Activates the F section of the units display.

7 (34) G

1

Activates the G section of the units display.

8 (33) E

1

Activates the E section of the units display.

9 (32) D

2

Activates the D section of the tens display.

10 (31) C

2

Activates the C section of the tens display.

11 (30) B

2

Activates the B section of the tens display.

12 (29) A

2

Activates the A section of the tens display

13 (28) F

2

Activates the F section of the tens display.

14 (27) E

2

Activates the E section of the tens display.

15 (26) D

3

Activates the D section of the hundreds display.

16 (25) B

3

Activates the B section of the hundreds display.

17 (24) F

3

Activates the F section of the hundreds display.

18 (23) E

3

Activates the E section of the hundreds display.

19 (22) AB

4

Activates both halves of the 1 in the thousands display.
20 (21) POL Activates the negative polarity display.
21 (20) BP Backplane drive output.
22 (19) G

3

Activates the G section of the hundreds display.
23 (18) A

3

Activates the A section of the hundreds display.
24 (17) C

3

Activates the C section of the hundreds display.
25 (16) G

2

Activates the G section of the tens display.
26 (15) V

–

Negative power supply voltage.
27 (14) V

INT

The integrating capacitor should be selected to give the maximum voltage

swing that ensures component tolerance build-up will not allow the integrator

output to saturate. When analog common is used as a reference and the

conversion rate is 3 readings per second, a 0.047 µF capacitor may be used.

The capacitor must have a low dielectric constant to prevent roll-over errors.

See Integrating Capacitor section for additional details.
28 (13) V

BUFF

Integration resistor connection. Use a 180 kΩ for a 200 mV full-scale range

and a 1.8 MΩ for 2V full-scale range.
29 (12) C

AZ

The size of the auto-zero capacitor influences the system noise. Use a 0.47 µF

capacitor for a 200 mV full scale, and a 0.1 µF capacitor for a 2V full scale. See

paragraph on Auto-Zero Capacitor for more details.
30 (11) V

IN

–

The low input signal is connected to this pin.
31 (10) V

IN

+

The high input signal is connected to this pin.
32 (9) ANALOG This pin is primarily used to set the analog common-mode voltage for battery

operation or in systems where the input signal is referenced to the power

supply. See paragraph on Analog Common for more details. It also acts as a

reference voltage source.