Wing Shing WS7107CPL, WS7106CPL Datasheet

Features

3 Digit LCD/LED Display A/D
Converters

1

2

/

WS7106 / WS7107

WS7107CPL

0 to70

40Ld PDIP

E40.6

WS7106CPL

0 to 70

40Ld PDIP

E40.6

Pinouts

WS7106CPL (PDIP)

WS7107CPL (PDIP)

- LCD WS7106, LED WS7107

The WS7106 and WS7107

The WS7106

WS

The WS7106 and WS

True differential
inputs and reference are useful in all systems, but give the
desiger an uncommon advantage when measuring load
cells, strain gauges and other bridge type transducers.
Finally, the true economy of single power supply operation
(WS7106), enables a high performance panel meter to built
with the addition of only 10 passive compoents and a disply.

• True Differential Input and Reference, Direct Display
Drive

• On Chip Clock and Reference

• No Additional Active Circuits Required

Guaranteed Zero Reading for 0V Input on All Scales

True Polarity at Zero for Precise Null Detection

Typically Less Than 10mW

•

•

•Low Noise - Less Than 15µV

•Low Power Dissipation -

Ordering Information

TEMP.

PART NO.

RANGE (oC) PACKAGE PKG. NO.

P-P

Description

power, 3

1

/2digit A/D converters. Included are seven seg-

ment decoders, display drivers, a reference, and a clock.

isdesignedtointerfacewithaliquidcrystaldis-

play (LCD) and includes a multiplexed backplane drive; the

7107willdirectlydriveaninstrumentsizelightemitting

diode (LED) display.

7107bringtogetheracombinationof

highaccuracy,versatility,andtrueeconomy.

arehighperformance,low

(10’ s)

(100’ s)

(1000) AB4

(MINUS)

Wing Shing Computer Components Co., (H.K.)Ltd. Tel:[phone] Fax:[phone]
Homepage: http://www.wingshing.com E-mail: [e-mail]

(1’ s)

V+
D1
C1
B1
A1
F1
G1
E1
D2
C2
B2
A2
F2
E2
D3
B3
F3
E3

POL

1
2
3
4
5
6
7
8

9
10
11
12
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

OSC 1
OSC 2
OSC 3
TEST
REF HI
REF LO

+

C

REF

-

C

REF

COMMON
IN HI
IN LO
A-Z
BUFF
INT
V­G2 (10’s)
C3

(100’ s)

A3
G3
BP/GND

Absolute Maximum Ratings Thermal Information

2

WS7106/WS710

Supply Voltage Thermal Resistance (typical, Note 2) θJA(℃/W)

WS7106, V+ to V-…………………………….15v PDIP Package……………………………………………. …… ………… 50

WS7107, V+ to GND…………………….……6V Maximum Junction Temperature…………………………………….. ………150℃
WS7107, V_ to GND……………………. ….-9V Maximum Storage Temperature Range………………….………..-65℃ to 150℃

Analog Input Voltage (Either Input) (Note 1)V+ to V­Reference Input Voltage (Either Input)V+ to V­Clock Input

WS7106TEST to V+
WS7107GND to V+

Operating Conditions

Temperature Range…………………………0℃ to 70℃

CAUTION: Stresses above those listed in “absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation
Of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.

Notes:

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

2. Θ

Is measured with the component mounted on an evaluation PC on board in fee air.

JA

Electrical specifications

PARAMETER

(Note 3)

TEST CONDITIONS MIN TYP MAX UNIT

SYSTEM PERFORMACE

Zero Input Reading VIN=0.0V, FULL Scale = 200mV -000.0 ±000.0 +000.0

Ratiometric Reading VIN = V

-V

Rollover Error

Difference in Reading for Equal Positive and

, V

REF

=+VIN=200mV

IN

= 100mV 999 999/1000 1000

REF

-1 0.2 +1 Counts

Digital

Reading

Digital

Reading

Negative Inputs Near Full Scale

Linearity

Common Mode Rejection Ratio V

Full Scale = 200mV or Full Scale = 2V Maximum

Deviation from Best Straight Line Fit (note 6)

= 1V, VIN = 0V, Full Scale = 200mv(Note 6) - 50 - μV/V

CM

-1 0.2 +1 Counts

End Power Supply Character V+ Supply Current VIN = 0 (Does Not Include LED Current for WS7107 - 0.5 1.8 mA

End Power Supply Character V- Supply Current WS7107 Only - 0.5 1.8 mA

COMMON Pin Analog Common Voltage

25kΩ Between Common and Positive Supply (With

Respect to + Supply)

2.4 3.0 3.2 V

Noise (PK-PK Value not exceeded 95% of time) VIN=0V Full Scale=200mV 15 uV

Input Leakage Current VIN=0V 1 10 pA

P-P

Analog COMMON Temperature Coefficient 25K between Common and V+ 0℃-70℃ 60 75 ppm/℃

Scale Factor Temperature Coefficient VIN=199mV 0℃-70℃Ext. ref. 0ppm/℃ 60 75 ppm/℃

Zero Reading Drift VIN=0℃V-70℃ 0.2 1 uV/℃

DISPLAY DRIVER WS7106 ONLY

Peak-to-Peak Segment Drive Voltage

Peak-to-Peak Backplane Drive Voltage

V+ = to V- = 9V (Note 5) 4 5 6 V

Electrical Specifications (Continued)

WS7106 / WS7107

WS7107 ONLY

2. Back plane drive is in phase with segment drive for 'off' segment, 180 degrees out of phase for 'on' segment. Frequency is 20
times conversion rate. Average DC component is less than 50mV

WS7106

WS7107

FIGURE 1. WS

FIGURE 2. WS

3

DISPLAY DRIVER

(Note 1)

1.

3. Not tested, Quaranteed by design.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Segment Sinking Current V+ = 5V, Segment Voltage = 3V

(Except Pins 19 and 20) 58- mA
Pin 19 Only 10 16 - mA
Pin 20 Only 47- mA

NOTES:

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

Typical Applications and Test Circuits

+ -

R

C

+

C

REF

5

1

-

REF

COM

C

DISPLAY

R

1

R

R

3

4039383736353433323130

OSC 1

OSC 2

V+

D1C1B1

123456789

4

C

4

TEST

OSC 3

REF HI

REF LO

A1F1G1E1D2C2B2

IN

C

5

C

2

IN HI

IN LO

101112

9V

+

-

R

2

C

3

28

29

27262524232221

V-

INT

A-Z

BUFF

F2

E2

A2

D3

13

14151617181920

DISPLAY

G2

B3

C1 = 0.1µF

= 0.47µF

C

2

= 0.22µF

C

C3

A3

G3

BP

F3

E3

AB4

POL

3

C

= 100pF

4

= 0.02µF

C

5

= 24kΩ

R

1

R

= 47kΩ

2

= 100kΩ

R

3

= 1kΩ

R

4

R

= 1MΩ

5

7106TESTCIRCUITANDTYPICALAPPLICATIONWITHLCDDISPLAYCOMPONENTSSELECTEDFOR200mV

FULL SCALE

+5V -5V

R

1

C

R

C

4

OSC 3

TEST

4

REF HI

+

C

REF LO

F1

G1

R

3

4039383736353433323130

OSC 1

OSC 2

V+D1C1B1A1
123456789

+ -

IN

R

5

C

5

R

2

COM

DISPLAY

C

IN HI

IN LO

101112

1

-

REF

REF

C

E1D2C2B2A2F2E2D3B3F3E3

C

2

3

28

29

27262524232221

INT

A-Z

BUFF

13

14151617181920

V-

DISPLAY

G2

C1 = 0.1µF

= 0.47µF

C

2

= 0.22µF

C

C3

A3

G3

GND

AB4

POL

3

C

= 100pF

4

= 0.02µF

C

5

= 24kΩ

R

1

R

= 47kΩ

2

= 100kΩ

R

3

= 1kΩ

R

4

R

= 1MΩ

5

7107TESTCIRCUITANDTYPICALAPPLICATIONWITHLEDDISPLAYCOMPONENTSSELECTEDFOR200mV

FULL SCALE

Design Information Summary Sheet

WS7106 / WS7107

WS

WS7106 DISPLAY: LCD

WS7107 POWER SUPPLY: DUAL +5.0V

_

WS7107 DISPLAY: LED

4

• OSCILLATOR FREQUENCY

= 0.45/RC

f

OSC

C

> 50pF; R

OSC

f

(Typ) = 48kHz

OSC

• OSCILLATOR PERIOD

= RC/0.45

t

OSC

• INTEGRATION CLOCK FREQUENCY

CLOCK

= f

OSC

f

• INTEGRATION PERIOD

= 1000 x (4/f

t

INT

• 60/50Hz REJECTION CRITERION

t

INT/t60Hz

or t

• OPTIMUM INTEGRATION CURRENT

= 4µA

I

INT

• FULL SCALE ANALOG INPUT VOLTAGE

(Typ) = 200mV or 2V

V

lNFS

• INTEGRATE RESISTOR

V

R

INT

---------------- -=

I

INFS

INT

• INTEGRATE CAPACITOR

t

()I

C

INT

INT

--------------------------------=

V

INT

• INTEGRATOR OUTPUT VOLTAGE SWING

t

()I

V

•V

INT

INT

INT

--------------------------------=

C

INT

MAXIMUM SWING:

(V- + 0.5V) < V

> 50kΩ

OSC

/4

)

OSC

lNT/t60Hz

()

INT

()

INT

INT

= Integer

< (V+ - 0.5V), V

(Typ) = 2V

INT

• DISPLAY COUNT

V

IN

COUNT 1000

×=

---------------

V

REF

• CONVERSION CYCLE

t

CYC

t

CYC

when f

= t
= t

OSC

CL0CK

x 16,000

OSC

= 48kHz; t

x 4000

CYC

= 333ms

• COMMON MODE INPUT VOLTAGE

(V- + 1V) < V

< (V+ - 0.5V)

lN

• AUTO-ZERO CAPACITOR

0.01µF < C

AZ

< 1µF

• REFERENCE CAPACITOR

0.1µF < C

•V

COM

REF

< 1µF

Biased between Vi and V-.

COM

≅ V+ - 2.8V

•V

Regulation lost when V+ to V- < ≅6.8V
If V
the V

is externally pulled down to (V+ to V-)/2,

COM

circuit will turn off.

COM

7106 POWER SUPPLY:SINGLE 9V

V+ - V- = 9V
Digital supply is generated internally

≅ V+ - 4.5V

V

GND

•

Type: Direct drive with digital logic supply amplitude.

•

V+ = +5V to GND
V- = -5V to GND
Digital Logic and LED driver supply V+ to GND

•

Type: Non-Multiplexed Common Anode

Typical Integrator Amplifier Output Waveform (INT Pin)

AUTO ZERO PHASE

(COUNTS)
2999 - 1000

SIGNAL INTEGRATE

PHASE FIXED
1000 COUNTS

TOTAL CONVERSION TIME = 4000 x t

DE-INTEGRATE PHASE

0 - 1999 COUNTS

= 16,000 x t

CLOCK

OSC

Detailed Description

WS7106 / WS7107

WS7106 and

WS

WS7106 AND WS7107

5

Analog Section

Figure3showstheAnalogSectionforthe

7107.Eachmeasurementcycleisdividedintothree
phases. They are (1) auto-zero (A-Z), (2) signal integrate
(INT) and (3) de-integrate (DE).

Auto-Zer o Phase

During auto-zero three things happen. First, input high and
low are disconnected from the pins and internally shorted to
analog COMMON. Second, the reference capacitor is
charged to the reference voltage. Third, a feedback loop is
closed around the system to charge the auto-zero capacitor
C

to compensate for offset voltages in the buffer amplifier,

AZ

integrator,and comparator. Since the comparator is included
in the loop, the A-Z accuracy is limited only by the noise of
the system. In any case, the offset referred to the input is
less than 10µV.

Signal Integrate Phase

During signal integrate, the auto-zero loop is opened, the
internal short is removed, and the internal input high and low
are connected to the external pins. The converter then
integrates the differential voltage between IN HI and IN LO
for a fixed time. This differential voltage can be within a wide
common mode range: up to 1V from either supply. If, on the
other hand, the input signal has no return with respect to the
converter power supply, IN LO can be tied to analog
COMMON to establish the correct common mode voltage. At

the end of this phase, the polarity of the integrated signal is
determined.

De-Integrate Phase

The final phase is de-integrate, or reference integrate. Input
low is internally connected to analog COMMON and input
high is 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.
Specifically the digital reading displayed is:

V



IN

---------------

DISPLAY COUNT = 1000

.



V



REF

Differential Input

The input can accept differential voltages anywhere within the
common mode range of the input amplifier,or specifically from

0.5V below the positive supply to 1V above the negative sup­ply. In this range, the system has a CMRR of 86dB typical.
Howev er, care must be exercised to assure the integrator out­put does not saturate. A worst case condition would be a large
positive common mode voltage with a near full scale negative
differential input voltage. The negative input signal drives the
integrator positive when most of its swing has been used up
by the positive common mode voltage. For these critical appli­cations the integrator output swing can be reduced to less
than the recommended 2V full scale swing with little loss of
accuracy. The integrator output can swing to within 0.3V of
either supply without loss of linearity.

IN HI

COMMON

IN LO

STRAY STRAY

REF HI

+

C

REF

V+

31

32

30

34

10µA

INT

A-Z

INT

C

REF

REF LO

36

A-Z A-Z

DE- DE+

A-Z AND DE(±)

FIGURE 3.ANALOG SECTION OF

35

DE-DE+

R

INT

-

C

REF

33

-

+

INPUT

HIGH

N

V-

BUFFER

28 29 27

-

+

V+

1

2.8V

C

AZ

A-Z INT

INTEGRATOR

6.2V

INPUT
LOW

A-Z

-

+

COMPARATOR

C

INT

-

+

TO
DIGITAL
SECTION