SGS Thomson Microelectronics TEA2031A Datasheet

COLOR TV EA S T-WEST CO RR ECT IO N

.

BUILD IN FRAME PARABOLA FROM EXTER­NAL SA W-TOOTH

.

P A RA BO L A CORRECTI O N A DJUSTMENT

.

KEYST ONE CO RRECT ION AD JUSTME NT

.

LINE SI ZE A DJ US TM EN T

.

LINE DYNAMIC CORRECTION POSSIBILITY
(beam current)

.

D CLASS OUTPUT MODULATOR WITH
BUILD IN RECOVERY DIODE

.

50 OR 60Hz OPERATION

.

LOW DISSI PATION

.

FEW EXTERNAL COMPONENTS

DESCRIPTION

The TEA2031A is intended to ensure frame rate
modulated parabolic and keystone corrections to
the horizontal deflection circuitry of 110
sets.

The linear frame saw-tooth is applied to appropri­ate circuitry from which a corresponding parabolic
waveforms is obtained. This waveform is then fed
to a comparator together with the linear line saw­tooth for co mparison. Comparator ’s output drives
the output power stage which is capable of sinking
the external coil currents of up to 0.5A.

An internal recovery diode feeds back to the power
supply the coil f ly-back current pulses of as high as

0.5A.

o

color TV

TEA2031A

DIP8

(Plastic Package)

ORDER CODE : TEA2031A

PIN CONNECTIONS

1 AND 2 CAN BE INVERTED

May 1993

MULTIPLIER INPUT 1
MULTIPLIER INPUT 2

CURRENT REFERENCE

GROUND

1
2
3
4

8

COMPARATOR INPUT 2

7

MULTIPLIER OUTPUT AND COMPARATOR INPUT 1
V POWER SUPPLY

6

CC

5

OUTPUT

2031A-01.EPS

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TEA2031A

BLOCK DIAG RAM

100k

Ω

Line SAW-TOOTH

50µA

120µA

+24V

V

CC

6587

Comparator

V

CC

6.8mH
To DIODE

MODULATOR

Multiplier

i

1

1234

Ω

Ω

39k

39k

DC

Frame

SAW-TOOTH

GENERAL DES CRI PTI O N

The TEA2031A is int ended to provide to 110o color
TV sets a parabolic and keystone fr ame rate modu­lated correction in addition to the main horizontal
scanning.

A stable 6.3V internal reference provides current
and voltage references to the whole I C.

Pins 1 and 2 are two symmetrical inputs of an
on-chip multiplier circuit and are internally held at

6.3V reference potential level. Current inputs to
these pins are drawn from external sources via
appropriate resistors. The frame saw-tooth wave­form which has a peak-to-peak value of around 3
volts and a mean value of about 2.5 volt s, supplies
the required current via a series resistor t o pin 1.
Likewise, the current to pin 2 is drawn through a
series resistor from an ext ernal dc voltage s ource.
These series resistors can have values of around
40kΩ resulting in input currents of approximately

0.1mA ± modulation current.
Pin 7 should be loaded to ground through a 100kΩ

resistor which as a result will produce a parabola

12

6.3V

Ω

22k

2

TEA2031A

K . (I - I )

V

REF

i

2

of 5 volts peak-to-peak at pin 7. This parabola is
symmetrical if the DC current flowing into pin 2 is
equal to the mean input current of pin 1. Otherwise,
the parabola becomes dissymmetrical and pro­duces a keystone effect correction.

The line saw-tooth at pin 8 is obtained by feeding
the line fly-back voltage through an integrator net­work formed by a diode and a grounded capacitor
(see typical application diagram). The DC compo­nent of the line saw-tooth is compe nsated by an
internal current sinking source ; so that the mean
DC values of line saw-tooth and frame parabola
voltages are equal.

Line saw-tooth and frame parabola signals are
applied to a comparator whose output is in the form
of width modulated pulses. During every pulse
duration, the output (pin 5) can sink external coil
currents of up to 0.5A associated with diode modu­lator of the main horizontal scanning circuit.

An internal recovery diode feeds back the fly -back
energy of the coil to the power supply. This diode
can carry currents of up to 0.5A.

2031A-02.EPS

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