TDA2579C View Datasheet(PDF) - Philips Electronics

Part Name

Description

Manufacturer

TDA2579C

Synchronization circuit with synchronized vertical divider system for 60 Hz

Philips Electronics 

Philips Semiconductors

Synchronization circuit with synchronized

vertical divider system for 60 Hz

Preliminary specification

TDA2579C

FEATURES

Synchronization and horizontal part

• Horizontal sync separator and noise inverter

• Horizontal oscillator

• Horizontal output stage

• Horizontal phase detector (sync to oscillator)

• Triple current source in the phase detector with

automatic selection

• Normal phase detector time constant is increased to fast

during the vertical blanking period (external switching for

VTR conditions not necessary)

• Slow phase detector time constant and gated sync pulse

operation are automatically switched on by an internal

sync pulse noise level detection circuit

• Fast phase detector time is switched on for locking

• Time constant externally switchable

• Inhibit of horizontal phase detector and video transmitter

identification circuit during equalizing pulses and vertical

sync pulse

• Inhibit of horizontal phase detector during separated

vertical sync pulse

• Second phase detector for storage compensation of the

line output stage

• 3-level sandcastle pulse generator

• Automatic adaption of the burst key pulse width

• Video transmitter identification circuit

• Stabilizer and supply circuit for starting the horizontal

oscillator and output stage directly from the mains

rectifier

• Horizontal output current with constant duty factor value

of 55%

• Duty factor of the horizontal output pulse is 55% when

the horizontal flyback pulse is absent.

Vertical part

• fV = 60 Hz (M) system

• Vertical synchronization pulse separator without

external components and two integration times

• Zener diode reference voltage source for the vertical

sawtooth generator and vertical comparator

• Divider system with three different reset enable windows

• Synchronization is set to 528 divider ratio when no

vertical sync pulse and no video transmitter is identified

• Divider window is forced to wide window when a vertical

sync pulse is detected within the window provided by

reset divider and end of vertical blanking period, on

condition that the voltage on pin 18 is ≤1.2 V

• Divider ratio is 528 (fV = 60 Hz) for DC signal on pin 5

• Linear negative-going sawtooth generated via the

divider system (no frequency adjustment)

• Comparator with low DC level feedback signal

• Output stage driver

• fV = 60 Hz identification output combined with mute

function

• Start of vertical blanking is shifted to the start of the

pre-equalizing pulses when the divider ratio is between

522 and 528 lines per picture

• Guard circuit which generates the vertical blanking

pulse level on the sandcastle output pin 17 when the

feedback level at pin 2 is not within the specified limits.

GENERAL DESCRIPTION

The TDA2579C is an integrated circuit generating all

requirements for synchronization of its horizontal oscillator

and output stage plus those of the vertical part which

comprises a divider system, sawtooth generator,

comparator and output stage.

The TDA2579C is almost identical to the TDA2579B.

It is optimized for the M (60 Hz) TV system.

ORDERING INFORMATION

EXTENDED TYPE

NUMBER

TDA2579C

PINS

18

PACKAGE

PIN POSITION

MATERIAL

DIL

plastic

CODE

SOT102

January 1994

2

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