TDA9105 ST Microelectronics, TDA9105 Datasheet - Page 20

• Manufacturer Part Number: TDA9105
• Description: DEFLECTION PROCESSOR FOR MULTISYNC MONITORS
• Manufacturer: ST Microelectronics

TDA9105
OPERATING DESCRIPTION (continued)
Geometric Corrections (continued)
Figure 20 : Geometric Corrections Principle
For E/Wpart and Dynamic Horizontal phase control
part, a sawtooth shaped differential current in the
following form is generated: I’ = k’ (V
Then I and I’ are added together and converted
into voltage.
These two parabola are respectively available on
Pin 37 and Pin 40 by the way of an emitter follower
which has to be biased by an external resistor
(10k ). They can be DC coupled with external
circuitry.
EW
K
K
20/32
1
1
’ is adjustable by KEYST control (Pin 38)
is adjustable by EW amp control (Pin 39)
VERTICAL RAMP
V
OUT
= 2.5V + K
+ K
ANALOG MULTIPLIER
1
(V
VDCIN
RAMP
1
’ (V
2
RAMP
RAMP
- V
DCIN
-V
- V
)
VDCIN
VDCIN
DCIN
2
DCIN
).
)
SIDEPIN AMP
KEY BALANCE
KEYSTONE
EW AMP
Dyn. Hor.
Phase Control
K
K
For vertical dynamic focus part, only a constant
amplitude parabola is generated in the form :
The output connection is the same as the two other
corrections (Pins 37-40).
It is important to note that the parasitic parabola
during the discharge of the vertical oscillator ca-
pacitor is suppressed.
2
2
’ is adjustable by KEYBAL control (Pin 41)
is adjustable by SPB amp control (Pin 42)
V
OUT
= 6V - 0.75 x (V
V
SIDE PIN BAL. OUT
VERT. DYN. FOCUS OUT
OUT
EW OUT
= 4V + K
+ K
2
AMP
(V
2
RAMP
’ (V
- V
RAMP
DCIN
- V
DCIN
)
- V
2
.
DCIN
)
2
)