TDA8145 TV EAST/WEST CORRECTION CIRCUIT FOR SQUARE TUBES LOW DISSIPATION

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Cori Summers
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TV EAST/WEST CORRECTION CIRCUIT FOR SQUARE TUBES LOW DISSIPATION SQUARE GENERATOR FOR PARABOLIC CURRENT SPECIALLY DESIGNED FOR SQUARE CRT CORRECTION EXTERNAL KEYSTONE ADJUSTMENT (symmetry of the

1 TV EAST/WEST CORRECTION CIRCUIT FOR SQUARE TUBES LOW DISSIPATION SQUARE GENERATOR FOR PARABOLIC CURRENT SPECIALLY DESIGNED FOR SQUARE CRT CORRECTION EXTERNAL KEYSTONE ADJUSTMENT (symmetry of the parabola) INPUT FOR DYNAMIC FIELD CORRECTION (beam current change) STATIC PICTURE WIDTH ADJUSTMENT PULSE-WIDTH MODULATOR FINAL STAGE D-CLASS WITH ENERGY REDELIVERY PARASITIC PARABOLA SUPPRESSION, DURING FLYBACK TIME OF THE VERTICAL SAWTOOTH POWERDIP8 (Th = 0mm) (Plastic Package) ORDER CODE : DESCRIPTION The is a monolithic integrated circuit in a 8 pin minidip plastic package designed for use in the square CRT east-west pin-cushion correction by driving a diode modulator in TV and monitor applications PIN CONNECTIONS (top view) KEYSTONE CORRECTION INPUT 8 NON-INVERTING INPUT 00µA CURRENT SINK FRAME SAWTOOTH CURRENT INPUT PARABOLA OUTPUT INVERTING INPUT CURRENT REFERENCE + GND OUTPUT 8-0EPS October 998 /

2 SCHEMATIC DIAGRAM CURRENT LIMITER 8 COMPARATOR AND OUTPUT STAGE + Q Q - V BE Q Q Q V REF Q R Q Q8 Q D Q R R R OP R Q Q9 OUTPUT OP R Q R Q R8 Q0 I IN Q VS - VBE Q Q0 Q D D OP Q I REF GND Q8 Q9 R9 R0 R R R Z FULL-WAVE RECTIFIER PARABOLA NETWORK CURRENT REFERENCE 8-0EPS ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit V s Supply Voltage V I s Supply Current 00 ma P tot Power Dissipation at T amb = 0 C 00 mw T stg, T j Storage and Junction Temperature to 0 C 8-0TBL THERMAL DATA Symbol Parameter Value Unit R th (j c) Thermal Resistance Junction-ambient Max 00 C/W R th (j a) Thermal Resistance Junction-pin Max 0 C/W 8-0TBL ELECTRICAL CHARACTERISTICS (Tamb = o C, VS = V, Vfr = 0, S and S in "a" position, refer to the test circuit unless otherwise specified) Symbol Parameter Test Conditions Min Typ Max Unit Supply Voltage 0 V I S Supply Current ma V ref Internal Reference Voltage V I ref Internal Reference Current V ref /R 0 ma V (*) (A) Pin Output Voltage I fr = 0 µa 0 V V (*) (B) Pin Output Voltage I fr = 0 µa V 8-0TBL /

3 ELECTRICAL CHARACTERISTICS (Tamb = o C, VS = V, Vfr = 0, S and S in "a" position, refer to the test circuit unless otherwise specified) (continued) Symbol Parameter Test Conditions Min Typ Max Unit K K Parabola Coefficient (see Figure ) Parabola Coefficient (see Figure ) K = V A V B V A V C 0 K = V A V C V A V D 00 V (*) V = V E V F 0 0 mv I 8 Current Source S b 00 µa ATL Saturation Voltage I o = 00 ma Sink S b V ATH Saturation Voltage I o = 00 ma Source S c S b 08 V V F Forward Voltage I o = 00 ma S d S b V I fr Frame Sawtooth Current V fr = V pp µa 8-0TBL Figure : Test Circuit R R 0kΩ 0kΩ I FR V F ATH I O V FR R 0kΩ R kω R V REF 8 R8 0kΩ S I F d a b c -I O ATL a S b 8-0EPS Figure : Parabola Characteristics V (V) V A VB V C VD V E V F I FR (µa) 8-0EPS /

4 APPLICATION CIRCUIT WITH KEYSTONE CORRECTION Line Transformer (LT) LM L 0mH R Pin-cushion adjustment RT Pin Voltage V FRAME R = V FRAME µa PP kω kω R 8kΩ C 00nF C nf 8 Keystone Adj RT 00kΩ R kω C nf D N8 Hfly from LT R RT kω H Width 8-0EPS CIRCUIT OPERATION (see the schematic diagram) A differential amplifier OP is driven by a vertical frequency sawtooth current of ± µa which is produced via an external resistor from the sawtooth voltage The non inverting input of this amplifier is connected with a reference voltage corresponding to the DC level of the sawtooth voltage This DC voltage should be adjustable for the keystone correction The rectified output current of this amplifier drives the parabola network which provides a parabolic output current This output current produces the corresponding voltage due to the voltage drop across the external resistor at pin If the input is overmodulated (> 0µA) the internal current is limited to 0µA This limitation can be used for suppressing the parasitic parabolic current generated during the flyback time of the frame sawtooth A comparator OP is driven by the parabolic current The second input of the comparator is connected with a horizontal frequency sawtooth voltage the DC level of which can be changed by the external circuitry for the adjustment of the picture width The horizontal frequency pulse width modulated output signal drives the final stage It consists of a class D push pull output amplifier that drives, via an external inductor, the diode modulator /

5 PACKAGE MECHANICAL DATA 8 PINS - PLASTIC POWERDIP PM-DIP8EPS Dimensions Millimeters Inches Min Typ Max Min Typ Max A 00 a B B b b D E 88 0 e 000 e 000 e 000 F 080 I L 00 Z DIP8PWTBL Information furnished is believed to be accurate and reliable However, STMicroelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use No licence is granted by implication or otherwise under any patent or patent rights of STMicroelectronics Specifications mentioned in this publication are subject to change without notice This publication supersedes and replaces all information previously supplied STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics The ST logo is a registered trademark of STMicroelectronics 998 STMicroelectronics - All Rights Reserved Purchase of I C Components of STMicroelectronics, conveys a license under the Philips I C Patent Rights to use these components in a I C system, is granted provided that the system conforms to the I C Standard Specifications as defined by Philips STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco - The Netherlands Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - USA /

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