Selected language     English  ▼

TDA4855 Datasheet(PDF) 9 Page - NXP Semiconductors

Part No. TDA4855
Description  Autosync Deflection Controller ASDC
Download  44 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  PHILIPS [NXP Semiconductors]

 9 page
background image
1996 Jul 18
Philips Semiconductors
Preliminary specification
Autosync Deflection Controller (ASDC)
To achieve a stabilized amplitude the free-running
frequency fosc(V), without adjustment, should be at least
10% lower than the minimum trigger frequency.
The contributions shown in Table 3 can be assumed.
Table 3
Calculation of fosc(V) total spread
Result for 50 to 110 Hz application:
Application hint: VAGC (pin 22) has a high input
impedance during scan, thus the pin must not be loaded
externally. Otherwise non-linearities in the vertical output
currents may occur due to the changing charge current
during scan.
Application hint: The full vertical sync range of 1 : 2.5 can
be made usable by incorporating an adjustment of the
free-running frequency. Also the complete sync range can
be shifted to higher frequencies (e.g. 70 to 160 Hz) by
reducing the value of CVCAP.
Adjustment of vertical size, vertical shift and
VPOS (pin 17) is the input for the DC adjustable vertical
picture shift. This pin provides a phase shift at the
sawtooth output 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.
The amplitude of the differential output currents at VOUT1
and VOUT2 can be adjusted via input VAMP (pin 18).
This can be a combination of a DC adjustment and a
dynamic waveform modulation.
VSCOR (pin 19) is used to adjust the amount of vertical
S-correction in the output signal.
The adjustments for vertical size and vertical shift also
affect the waveforms of the EW parabola and the vertical
S-correction. The result of this interaction is that no
Contributing elements:
Minimum frequency offset between fosc(V)
and lowest trigger frequency
Spread of IC
Spread of RVREF
Spread of CVCAP
osc V
50 Hz
42 Hz
readjustment of these parameters is necessary after an
adjustment of vertical picture size or position.
Application hint: VPOS is a current input, which provides
an internal reference voltage while IVPOS is in the specified
adjustment current range. By grounding VPOS (pin 17) the
symmetrical control range is forced to its centre value.
Application hint: VSCOR is a current input at 5 V.
Superimposed on this level is a very small positive-going
vertical sawtooth, intended to modulate an external
long-tailed transistor pair. This enables further optional DC
controls of functions which are not directly accessible such
as vertical tilt or vertical linearity (see Fig.17).
EW parabola (including horizontal size and trapezium
EWDRV (pin 11) provides a complete EW drive waveform.
EW parabola amplitude, DC shift (horizontal size) and
trapezium correction can be controlled via separate DC
EWPAR (pin 21) is used to adjust the parabola amplitude.
This can be a combination of a DC adjustment and a
dynamic waveform modulation.
The EW parabola amplitude also tracks with vertical
picture size. The parabola waveform itself tracks with the
adjustment for vertical picture shift (VPOS).
Additional effort has been taken to generate a smooth
waveform at the top of the parabola. This is to avoid ringing
in the horizontal output stage.
EWWID (pin 32) offers two modes of operation:
1. Mode 1
Horizontal size is DC controlled via EWWID (pin 32)
and causes a DC shift at the EWDRV output. Also the
complete waveform is 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 modulator stages which require a
voltage proportional to the line frequency.
2. Mode 2
EWWID (pin 32) is grounded. Then EWDRV is no
longer multiplied by the line frequency. The DC
adjustment for horizontal size must be added to the
input of the B+ control amplifier BIN (pin 5). This mode
is to be used for driving EW modulators which require
a voltage independent of the line frequency.
EWTRP (pin 20) is used to adjust the amount of trapezium
correction in the EW drive waveform.

Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42  43  44 

Datasheet Download

Related Electronics Part Number

Part NumberComponents DescriptionHtml ViewManufacturer
NTE7133Integrated Circuit Horizontal and Vertical Deflection Controller for VGA/XGA and Autosync Monitors 1 2 3 4 5 MoreNTE Electronics
TDA4841PSI2C-bus autosync deflection controller for PC monitors 1 2 3 4 5 MoreNXP Semiconductors
TDA4851Horizontal and vertical deflection controller for VGA/XGA and autosync monitors 1 2 3 4 5 MoreNXP Semiconductors
TDA4852Horizontal and vertical deflection controller for autosync monitors 1 2 3 4 5 MoreNXP Semiconductors
TDA4856I2C-bus autosync deflection controller for PC monitors 1 2 3 4 5 MoreNXP Semiconductors
TDA4857PSI2C-bus autosync deflection controller for PC monitors 1 2 3 4 5 MoreNXP Semiconductors
TDA4858Economy Autosync Deflection Controller EASDC 1 2 3 4 5 MoreNXP Semiconductors
LM1290Autosync Horizontal Deflection Processor 1 2 3 4 5 MoreNational Semiconductor (TI)
NTE7132Integrated Circuit Horizontal and Vertical Deflection Controller for VGA/XGA and Multi-Frequency Monitors 1 2 3 4 5 MoreNTE Electronics
NTE7134Integrated Circuit Horizontal and Vertical Deflection Controller for Monitors 1 2 3 4 5 MoreNTE Electronics

Link URL

Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Bookmark   |   Link Exchange   |   Manufacturer List
All Rights Reserved© 2003 - 2017    

Mirror Sites
English :  ,  |   Chinese :  |   German :  |   Japanese :  |   Russian :
Korean :   |   Spanish :  |   French :  |   Italian :  |   Portuguese :  |   Polish :