TDA4855 Datasheet, PDF (2/44 Pages) NXP Semiconductors – Autosync Deflection Controller ASDC

Philips Semiconductors
Autosync Deflection Controller (ASDC)
Preliminary specification
TDA4855
FEATURES
Concept features
• Full Horizontal (H) plus Vertical (V) autosync capability
• Completely DC controllable for analog and digital
concepts
• Excellent geometry control functions (e.g. automatic
correction of East-West (EW) parabola during
adjustment of vertical size and vertical shift)
• Flexible Switched Mode Power Supply (SMPS) function
block for feedback and feed forward converters
• Horizontal focus parabola with amplitude control
• X-ray protection
• Start-up and switch-off sequence for safe operation of
all power components
• Very good vertical linearity
• Internal supply voltage stabilization
• SDIP32 package.
Synchronization inputs
• Can handle all sync signals (Horizontal, Vertical,
Composite and Sync-on-video)
• Combined output for video clamping, vertical blanking
and protection blanking.
Horizontal section
• Extremely low jitter
• Frequency locked loop for smooth catching of line
frequency
• Simple frequency preset of f_min and f_max by external
resistors
• DC controllable wide range linear picture position
• Soft start for horizontal driver.
Vertical section
• Vertical amplitude independent of frequency
• Automatic correction of picture height for VGA350 and
VGA400 modes
• DC controllable picture height, picture position and
S-correction
• Differential current outputs for DC coupling to vertical
booster.
EW section
• Output for DC adjustable EW parabola with smoothed
top
• DC controllable picture width and trapezium correction
• Optional tracking of EW parabola with line frequency
• Prepared for additional DC controls of vertical linearity,
EW-corner, EW pin balance, EW parallelogram, vertical
focus by extended application.
GENERAL DESCRIPTION
The TDA4855 is a high performance and efficient solution
for autosync monitors. The concept is fully DC controllable
and can be used in applications with a microcontroller and
stand-alone in rock bottom solutions.
The TDA4855 provides synchronization processing, H + V
synchronization with full autosync capability, and very
short settling times after mode changes. External power
components are given a great deal of protection. The IC
generates the drive waveforms for DC-coupled vertical
boosters such as TDA486X and TDA8351.
The TDA4855 provides extended functions e.g. as a
flexible SMPS block and an extensive set of geometry
control facilities, providing excellent picture quality.
Together with the Philips TDA488X video processor family
a very advanced system solution is offered.
1996 Jul 18
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