TDA9109 STMicroelectronics, TDA9109 Datasheet - Page 22

• Manufacturer Part Number: TDA9109
• Description: Multimedia Misc DISC BY STM 11/99
• Manufacturer: STMicroelectronics
• Type: Low Cost Deflection Processorr

Specifications of TDA9109

• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Package / Case: SPDIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TDA9109/S
OPERATING DESCRIPTION (continued)
III.2 - I
S and C correction shapes can then be added to
this ramp. These frequency independent S and C
corrections are generated internally. Their ampli-
tudes are adjustable by their respective I
ters. They can also be inhibited by their select bits.
Finally, the amplitude of this S and C corrected
ramp can be adjusted by the vertical ramp ampli-
tude control register.
The adjusted ramp is available on Pin 23 (V
drive an external power stage.
The gain of this stage can be adjusted ( 25%)
depending on its register value.
The mean value of this ramp is driven by its own
I
VPOS = 7/16 V
Usually VOUT is sent through a resistive divider to
the inverting input of the booster. Since VPOS
derives from V
non-inverting input of the booster should also de-
rive from V
plication Diagram).
III.3 - Vertical Moiré
By using the vertical moiré, VPOS can be modu-
lated from frame to frame. This function is intended
to cancel the fringes which appear when line to line
interval is very close to the CRT vertical pitch.
The amplitude of the modulation is controlled by
register VMOIRE on sub-address 0C and can be
switched-off via the control bit D7.
III.4 - Basic Equations
In first approximation, the amplitude of the ramp on
Pin 23 (VOUT) is :
V
with :
- V
- V
- V
- VPOS is calculated by : VPOS = V
The current available on Pin 22 is :
with : C
22/30
2
C register (vertical position). Its value is
OUT
on Pin 22, typically 3.5V)
value and +1 for maximum
with V
register value and +1 for maximum
DCMID
OSC
AMP
- VPOS = (V
f : synchronization frequency.
2
= -1 for minimum vertical amplitude register
C Control Adjustments
= V
OSC
P
= 7/16 V
equals -1 for minimum vertical position
REF-V
22
: capacitor connected on Pin 22 and
I
OSC
(ramp with fixed amplitude)
REF-V
REF-V
to optimize the accuracy (see Ap-
OSC
REF
3
8
, the bias voltage sent to the
- V
V
(middle value of the ramp
300mV.
REF
DCMID
C
) (1 + 0.25 (V
OSC
DCMID
f
2
+ 0.3 V
C regis-
OUT
AMP
) to
))
P
III.5 - Geometric Corrections
The principle is represented in Figure 16.
Starting from the vertical ramp, a parabola-shaped
current is generated for E/W correction (also known
as Pin Cushion correction), dynamic horizontal
phase control correction, and vertical dynamic Fo-
cus correction.
The parabola generator is made by an analog
multiplier, the output current of which is equal to :
where VOUT is the vertical output ramp (typically be-
tween 2 and 5V) and V
One more multiplier provides a current proportional
to (V
The VOUT sawtooth is typically centered on 3.5V.
By changing the vertical position, the sawtooth
shifts by 0.3V.
In order to have good screen geometry for any end
user adjustment, the TDA9109/S has the "geome-
try tracking" feature, which allows generation of a
dissymetric parabola depending on the vertical
position.
Due to the large output stage voltage range (E/W,
Keystone, Corner), the combination of tracking
function with maximum vertical amplitude, maxi-
mum or minimum vertical position and maximum
gain on the DAC control may lead to the output
stage saturation. This must be avoided by limiting
the output voltage with apropriate I
values.
For the E/W part and the dynamic horizontal phase
control part, a sawtooth-shaped differential current
in the following form is generated :
Then
voltage for the E/W part.
Each of the three E/W components, and the two
dynamic horizontal phase controls may be inhibited
by their own I
The E/W parabola is available on Pin 24 via an
emitter follower output stage which has to be bi-
ased by an external resistor (10k
Since stable in temperature, the device can be DC
coupled with an external circuitry.
The vertical dynamic focus is available on Pin 10.
The dynamic horizontal phase control drives inter-
nally the H-position, moving the HFLY position on
the horizontal sawtooth in the range of
both for side pin balance and parallelogram.
OUT
I and
- V
DCMID
2
I = k (V
I’ = k’ (V
C select bit.
I’ are added and converted into
)
4
for corner correction.
DCMID
OUT
OUT
is 3.5V (for V
- V
- V
DCMID
DCMID
)
2
)
2
to ground).
REF-V
C registers
1.4% T
= 8V).
H