KB2511B View Datasheet(PDF) - Samsung
Part Name
Description
MFG CO.
KB2511B Datasheet PDF : 35 Pages
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KB2511B
DEFLECTION PROCESSOR FOR MULTISYNC MONITORS
VERTICAL PART
Geometric Corrections
The principle is represented in figure 17.
Parabola
Generator
VDCMID(3.5V)
2
I
V.Focus
AMP
Horizontal
Dynamic Focus
+
10
Dynamic focus
23
Vertical
Ramp VOUT
EW amp +
VDCMID
24
(3.5V)
keystone
EW output
sidepin
VDCMID
amp
+
To horizontal
phase
(3.5V)
Parallelogram
Sidepin balance
output current
Figure 17. Geometric Correcitions Principle
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• ( VOUT - VDCMID ) 2
Where Vout is the vertical output ramp(typically between 2 and 5V) and VDCMID is 3.5V(for VREF-V=8V). The VOUT
sawtooth is typically centered on 3.5V. By changing the vertical position, the sawtooth shifts by ±0.3V.
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, FOCUS), the combination of tracking function with maximum verti-
cal amplitude max or min vertical position and maximum gain on the DAC control may lead to the output stages
saturation. This must be avoided by limiting the output voltage by appropriate I2C registers values.
For E/W part and Dynamic Horizontal phase control part, a sawtooth shaped differential current in the following
form is generated:
∆I’ = k’ • ( VOUT - VDCMID )2
Then ∆I and ∆I’are added together and converted into voltage for the E/W part.
Each of the two E/W components or the two Dynamic horizontal phase control ones may be inhibited by their own
I2C select bit.
The E/W parabola is available on pin 24 by the way of an emitter follower which has to be biased by an external
resistor (10KΩ). It can be DC coupled with external circuitry.
Vertical dynamic focus is combined with horizontal one 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% Th both on side
pin balance and parallelogrm.
30
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