TDA4853 Datasheet, PDF (12/60 Pages) NXP Semiconductors – I2C-bus autosync deflection controllers for PC/TV monitors

Philips Semiconductors
I²C-bus autosync deflection controllers for
PC/TV monitors
Product specification
TDA4853; TDA4854
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).
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_HSMOD, the pincushion, corner and
trapezium component of the EWDRV output will be
reduced by a factor of 1 – ^V-----H---^S---^I-^Z---^E-----⁺----V-----^H--1-^E---4^H---.^T--4-^---1-----^–-----V-1------4--^H----.--^S--4----^I--^Z----V--^E----^--
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_HSIZE in the EWDRV output
signal, the DC component V_HEHT caused by I_HSMOD will be
reduced by a factor of 1 – ^V-1---4-H--.-^S-4--^I-^Z--V-^E- as shown in the equation
above.
The whole EWDRV voltage is calculated as follows:
V_EWDRV = 1.2 V + [V_HSIZE + V_HEHT × f(HSIZE) + (V_HPIN +
V_HCOR + V_HTRAP) × g(HSIZE, HSMOD)] × h(I_HREF)
Where:
V_HEHT = _1-I--^H-2--^S-0--^M----_µ^O----A^D-- × 0.69
f(HSIZE) = 1 – ^V-1---4-H--.-^S-4--^I-^Z--V-^E-
g(HSIZE, HSMOD)
=
1
–
V_HSIZE
+
V_HEHT


1
–
V-1---4-_{H--.-S-4--I-Z--V-E- }
-----------------------------1----4---.--4-----V-------------------------------
h(I_HREF) = _I--H----_R---_E-I--^HF---^R---_f^E--₌-^F--₇--₀--_k--_H--_z
Two different modes of operation can be chosen for the
EW output waveform via control bit FHMULT:
1. Mode 1
Horizontal size is controlled via register HSIZE and
causes a DC shift at the EWDRV output. The complete
waveform is also multiplied internally by a signal
proportional to the line frequency [which is detected
via the current at HREF (pin 28)]. This mode is to be
used for driving EW diode modulator stages which
require a voltage proportional to the line frequency.
2. Mode 2
The EW drive waveform does not track with the line
frequency. This mode is to be used for driving EW
modulators which require a voltage independent of the
line frequency.
Output stage for asymmetric correction waveforms
[ASCOR (pin 20)]
This output is designed as a voltage output for
superimposed waveforms of vertical parabola and
sawtooth. The amplitude and polarity of both signals can
be changed via registers HPARAL and HPINBAL.
Application hint: The TDA4854 offers two possibilities to
control registers HPINBAL and HPARAL.
1. Control bit ACD = 1
The two registers now control the horizontal phase by
means of internal modulation of the PLL2 horizontal
phase control. The ASCOR output (pin 20) can be left
unused, but it will always provide an output signal
because the ASCOR output stage is not influenced by
the control bit ACD.
2. Control bit ACD = 0
The internal modulation via PLL2 is disconnected.
In order to obtain the required effect on the screen,
pin ASCOR must now be fed to the DC amplifier which
controls the DC shift of the horizontal deflection. This
option is useful for applications which already use a
DC shift transformer.
If the tube does not need HPINBAL and HPARAL, then pin
ASCOR can be used for other purposes, i.e. for a simple
dynamic convergence.
1999 Jul 13
12