GS4911B/GS4910B
HD/SD/Graphics Clock and
Timing Generator with GENLOCK
GS4911B/GS4910B Data Sheet
Key Features
Video Clock Synthesis
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Generates any video or graphics clock up to 165MHz
Pre-programmed for 8 video and 13 graphics clocks
Accuracy of free-running clock frequency limited only by
crystal reference
One differential and two single-ended video/graphics
clock outputs
Each clock may be individually delayed for skew control
Video output clock may be directly connected to
Gennum’s serializers for a SMPTE-compliant HD-SDI
output
Description
The GS4911B is a highly flexible, digitally controlled
clock synthesis circuit and timing generator with
genlock capability. It can be used to generate video and
audio clocks and timing signals, and allows multiple
devices to be genlocked to an input reference.
The GS4910B includes all the features of the GS4911B,
but does not offer audio clocks or AFS pulse generation.
The GS4911B/GS4910B will recognize input reference
signals conforming to 36 different video standards and
16 different graphic formats, and will genlock the output
timing information to the incoming reference. The
GS4911B/GS4910B supports cross-locking, allowing
the output to be genlocked to an incoming reference
that is different from the output video standard selected.
The user may select to output one of 8 different video
sample clock rates or 13 different graphic display clock
rates, or may program any clock frequency between
13.5MHz and 165MHz. The chosen clock frequency
can be further divided using internal dividers, and is
available on two video clock outputs and one LVDS
video clock output pair. The video clocks are frequency
and phased-locked to the horizontal timing reference,
and can be individually delayed with respect to the
timing outputs for clock skew control.
Eight user-selectable timing outputs are provided that
can automatically produce the following timing signals
for 35 different video formats and 13 different graphics
formats: HSync, Hblanking, VSync, Vblanking, F sync,
F digital, AFS (GS4911B only), DE, and 10FID. These
timing outputs may be locked to the input reference
signal for genlock timing and may be phase adjusted via
internal registers.
In addition, the GS4911B provides three audio sample
clock outputs that can produce audio clocks up to 512fs
with fs ranging from 9.7kHz to 96kHz. Audio to video
phasing is accomplished by an external 10FID input
reference, a 10FID signal specified via internal
registers, or a user-programmed audio frame
sequence.
The GS4911B/GS4910B is Pb-free, and the
encapsulation compound does not contain halogenated
flame retardant (RoHS Compliant).
36655 - 2
April 2006
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www.gennum.com
Audio Clock Synthesis (GS4911B only)
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Three audio clock outputs
Generates any audio clock up to 512*96kHz
Pre-programmed for 7 audio clocks
Timing Generation
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Generates up to 8 timing signals at a time
Choose from 9 pre-programmed timing signals: H and V
sync and blanking, F Sync, F Digital, AFS (GS4911B
only), Display Enable, 10FID, and up to 4 user-defined
timing signals
Pre-programmed to generate timing for 35 different video
formats and 13 different graphic display formats
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Genlock Capability
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Clocks may be free-running or genlocked to an input
reference with a variable offset step size of 100-200ps
(depending on exact clock frequency)
Variable timing offset step size of 100-200ps up to one
frame
Output may be cross-locked to a different input reference
Freeze operation on loss of reference
Optional crash or drift lock on application of reference
Automatic input format detection
General Features
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Reduces design complexity and saves board space -
9mm x 9mm package plus crystal reference replaces
multiple VCXOs, PLLs and timing generators
Pb-free and RoHS Compliant
Low power operation typically 300mW
1.8V core and 1.8V or 3.3V I/O power supplies
64-PIN QFN package
Applications
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Video cameras; Digital audio and/or video recording/play
back devices; Digital audio and/or video processing
devices; Computer/video displays; DVD/MPEG devices;
Digital Set top boxes; Video projectors; High definition
video systems; Multi-media PC applications
GENNUM [ GENNUM CORPORATION ]
