DEFLECTION PROCESSOR FOR MULTISYNC MONITORS

S1D2512X01

30

Starting from the vertical ramp, a parabola shaped current is generated for E/W correction, dynamic horizontal

phase control correction, and vertical dynamic focus correction.

The base of the parabola generator is an analog multiplier, the output current of which is equal to:

∆I = k × (V

2

typically centered on 3.5V. By changing the vertical position, the sawtooth shifts by

In order to keep a good screen geometry for any end user preference adjustment we implemented the geometry

tracking.

Due to large output stages voltage range (E/W, keystone, corner), the combination of tracking function with

maximum vertical amplitude, max or min vertical position and maximum gain on the DAC control may lead to the

For E/W part and dynamic horizontal phase control part, a sawtooth shaped differential current in the following

form is generated:

∆I’ = k’ × (V

2

Then

∆I and ∆I’are added together and converted into voltage for the E/W part.

Each of the three E/W components, and the two dynamic horizontal phase control ones may be inhibited by their

The E/W parabola is available on pin 24 via an emitter follower which has to be biased by an external resistor

(10K

Ω). Since stable in temperature, the device can be DC coupled with an external circuitry.

The vertical dynamic focus is available on output pin 10. Dynamic horizontal phase control current drives internally

the H-position, moving the Hfly position on the horizontal sawtooth in the

± 1.4% T

parallelogram.

EW

4

Dynamic Horizontal Phase Control

Function

When the Synchronization pulse is not present, an internal current source sets the free running frequency. For an

Typical free running frequency can be calculated by:

fo Hz

()

1.5 10

5

–

1

C

OSC

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