FMS6408 Datasheet, PDF (1/9 Pages) Fairchild Semiconductor – Triple Video Filter Driver for RGB and YUV Signals

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FMS6408
Triple Video Filter Driver for RGB and YUV Signals
Features
• 7.6MHz 5th order RGB/YUV/YC CV filters
• 50dB stopband attenuation at 27MHz on all outputs
• Better than 0.5dB flatness to 4.2MHz on all outputs
• No external frequency selection components or clocks
• AC coupled inputs and AC or DC coupled outputs
• Supports both NTSC and PAL luminance bandwidth
• Continuous time low pass filters for video anti-aliasing
or reconstruction applications
• <1% differential gain with 0.5° differential phase on
all channels
• Integrated DC restore circuitry with low tilt
Applications
• Cable set top boxes
• Satellite set top boxes
• Terrestrial set top boxes
• DVD players
• Personal Video Recorders (PVR)
• Video On Demand (VOD)
Functional Block Diagram
INMUX (A/B)
Description
The FMS6408 provides three video signal paths including a
two-input mux, a video filter and a 6dB gain output driver.
The filter bandwidth supports RGB and YUV signals in
either NTSC or PAL formats.
The video filters approximate a 5th order Butterworth low
pass characteristic optimized for minimum overshoot and
flat group delay to provide excellent image quality. Four
different peaking options are available. The video filters can
be bypassed if desired.
In a typical application, the RGB or YUV DAC outputs are
AC coupled into the filters through the input mux. All
channels have DC restore circuitry to clamp the DC input
levels during video sync. The clamp pulse derived from the
selected Y input controls three independent feedback clamps.
All outputs are capable of driving 2Vpp, AC or DC coupled,
into either a single (150Ω) or dual (75Ω) video load. The
FMS6408 clamp levels can be factory programmed for YUV
/RGB (250mV for all channels), YC / YPbPr (250mV on
channel 1 and 1.125V on channels 2 and 3) or YC CV
(250mV on channels 1 and 3 and 1.125V on channel 2).
BYPASS (BYPASS/FILTER)
YINA
YINB
8MHz_*
gM
250mV
6dB
YOUT
Sync Processing
UINA
UINB
8MHz_*
gM
250mV or
1.125V *
VINA
VINB
8MHz_*
gM
250mV or
* Factory Selected Clamp
1.125V *
and Peaking Levels
6dB
UOUT
6dB
VOUT
REV. 2C August 31, 2004