1999 Dec 22

5

Philips Semiconductors

Product specification

Full bridge vertical deflection output circuit

in LVDMOS with east-west amplifier

TDA8358J

Guard circuit

A guard circuit with output pin GUARD is provided.

The guard circuit generates a HIGH-level during the

flyback period. The guard circuit is also activated for one

of the following conditions:

• During an open-loop condition.

The guard signal can be used for blanking the picture tube

and signalling fault conditions. The vertical

synchronization pulses of the guard signal can be used by

an On Screen Display (OSD) microcontroller.

Damping resistor compensation

HF loop stability is achieved by connecting a damping

significantly different. Both the resistor current and the

resulting in a too low deflection coil current at the start of

the scan.

The difference in the damping resistor current values

during scan and flyback have to be externally

compensated in order to achieve a short settling time.

connected between pins OUTA and COMP. The value of

where:

at flyback.

East-west amplifier

The east-west amplifier is a current driver sinking the

current of a diode modulator circuit. A feedback

the input and output of the inverting east-west amplifier in

order to convert the east-west correction input current into

an output voltage. The output voltage of the east-west

circuit at pin OUTEW is given by:

R

CMP

V

FB

V

loss FB

()

–

V

P

–

() R

D1

×

R

S

300

+

()

×

V

FB

V

loss FB

()

–

I

coil peak

()

R

coil

×

–

() R

M

×

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