TDA9105 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'TDA9105' PDF : 32 Pages View PDF
TDA9105
OPERATING DESCRIPTION (continued)
Geometric Corrections (continued)
Figure 20 : Geometric Corrections Principle
ANALOG MULTIPLIER
VERTICAL RAMP
2
VDCIN
VDCIN
EW AMP
KEYSTONE
VERT. DYN. FOCUS OUT
EW OUT
SIDEPIN AMP
VDCIN
SIDE PIN BAL. OUT
KEY BALANCE
For E/Wpart and Dynamic Horizontal phase control
part, a sawtooth shaped differential current in the
following form is generated: ∆I’ = k’ (VRAMP -VDCIN).
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
(10kΩ). They can be DC coupled with external
circuitry.
EW
VOUT = 2.5V + K1’ (VRAMP - VDCIN)
+ K1 (VRAMP - VDCIN)2
K1 is adjustable by EW amp control (Pin 39)
K1’ is adjustable by KEYST control (Pin 38)
Dyn. Hor.
VOUT = 4V + K2’ (VRAMP - VDCIN)
Phase Control
+ K2 (VRAMP - VDCIN)2
K2 is adjustable by SPB amp control (Pin 42)
K2’ is adjustable by KEYBAL control (Pin 41)
For vertical dynamic focus part, only a constant
amplitude parabola is generated in the form :
VOUT = 6V - 0.75 x (VAMP - VDCIN)2.
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.
20/32
Share Link: 
