TDA4857PS NXP Semiconductors, TDA4857PS Datasheet - Page 10

• Manufacturer Part Number: TDA4857PS
• Manufacturer: NXP Semiconductors

Specifications of TDA4857PS

• Lead Free Status / Rohs Status: Not Compliant

Philips Semiconductors
The adjustments for vertical size and vertical position also
affect the waveforms of the horizontal pincushion, vertical
linearity (S-correction), vertical linearity balance, focus
parabola, pin unbalance and parallelogram correction.
The result of this interaction is that no re-adjustment of
these parameters is necessary after an adjustment of
vertical picture size or position.
Adjustment of vertical position, vertical linearity and
vertical linearity balance
Register VPOS provides a DC shift at the sawtooth
outputs VOUT1 and VOUT2 (pins 13 and 12) and the EW
drive output EWDRV (pin 11) in such a way that the whole
picture moves vertically while maintaining the correct
geometry.
Register VLIN is used to adjust the amount of vertical
S-correction in the output signal. This function can be
switched off by control bit VSC.
Register VLINBAL is used to correct the unbalance of the
vertical S-correction in the output signal. This function can
be switched off by control bit VLC.
Adjustment of vertical moire cancellation
To achieve a cancellation of vertical moire (also known as
‘scan moire’) the vertical picture position can be modulated
by half the vertical frequency. The amplitude of the
modulation is controlled by register VMOIRE and can be
switched off via control bit MOD.
Horizontal pincushion (including horizontal size,
corner correction and trapezium correction)
EWDRV (pin 11) provides a complete EW drive waveform.
The components horizontal pincushion, horizontal size,
corner correction and trapezium correction are controlled
by the registers HPIN, HSIZE, HCOR and HTRAP.
HTRAP can be set to zero by control bit VPC.
The pincushion (EW parabola) amplitude, corner and
trapezium correction track with the vertical picture size
(VSIZE) and also with the adjustment for vertical picture
position (VPOS). The corner correction does not track with
the horizontal pincushion (HPIN).
2001 Apr 11
I
PC monitors
2
C-bus autosync deflection controller for
10
Further the horizontal pincushion amplitude, corner and
trapezium correction track with the horizontal picture size,
which is adjusted via register HSIZE and the analog
modulation input HSMOD.
If the DC component in the EWDRV output signal is
increased via HSIZE or I
trapezium component of the EWDRV output will be
reduced by a factor of
The value 14.4 V is a virtual voltage for calculation only.
The output pin can not reach this value, but the gain (and
DC bias) of the external application should be such that the
horizontal deflection is reduced to zero when EWDRV
reaches 14.4 V.
HSMOD can be used for a DC controlled EHT
compensation by correcting horizontal size, horizontal
pincushion, corner and trapezium. The control range at
this pin tracks with the actual value of HSIZE. For an
increasing DC component V
signal, the DC component V
reduced by a factor of
equation.
The whole EWDRV voltage is calculated as follows:
V
V
Where:
V
f(HSIZE)
g(HSIZE, HSMOD)
h I
EWDRV
HCOR
HEHT
HREF
+ V
=
= 1.2 V + [V
------------------- -
120 A
=
I
=
HTRAP
HSMOD
1
------------------------------- -
I
HREF
–
V
---------------- -
14.4 V
)
I
HREF
HSIZE
f
g(HSIZE, HSMOD)]
=
0.69
HSIZE
=
70kHz
1
1
1
HSMOD
–
–
–
V
---------------- -
14.4 V
+ V
V
------------------------------------------------------------------------ -
V
------------------------------------------------------------------------- -
HSIZE
HEHT
HSIZE
HSIZE
HSIZE
HEHT
, the pincushion, corner and
caused by I
as shown in the previous
+
+
in the EWDRV output
V
V
TDA4857PS
f(HSIZE) + (V
Product specification
HEHT
HEHT
14.4 V
14.4
h(I
1
1
HSMOD
HREF
–
–
V
---------------- -
14.4 V
V
---------------- -
14.4 V
HSIZE
HSIZE
)
HPIN
will be
+