©2004 Fairchild Semiconductor Corporation
1
www.fairchildsemi.com
September 2005
FMS6400 Rev. 1A
FMS6400 Dual Channel Video Drivers with Integrated Filters and Composite Video Summer
FMS6400
Dual Channel Video Drivers with Integrated Filters and
Composite Video Summer
Features
■ 7.1 MHz 5th order Y,C filters with composite summer
■ Selectable for 0dB or 6dB gain
■ 50dB stopband attenuation at 27MHz on Y, C and CV outputs
■ Better than 0.1 dB flatness to 4.5MHz on Y,C and CV outputs
■ No external frequency selection components or clocks
■ < 5ns group delay deviation on Y, C and CV outputs
■ AC-Coupled Inputs
■ AC or DC-Coupled Outputs
■ Capable of PAL frequency selection components or clocks
■ 0.3% / 0.2° differential gain/phase on Y,C and CV channels
■ Integrated DC restore circuitry with low tilt
■ Lead (Pb) Free SOIC-8 Package
Applications
■ Cable and Satellite set top boxes
■ DVD players
■ Personal Video Recorders (PVR)
■ Video On Demand (VOD)
Description
The FMS6400 is a dual Y/C 5th order Butterworth lowpass
video filter optimized for minimum overshoot and flat group
delay. The device also contains a summing circuit to generate
filtered composite video. In a typical application, the Y and C
input signals from DACs are AC coupled into the filters. Both
channels have DC restore circuitry to clamp the DC input levels
during video sync. The Y and C channels use separate feed-
back clamps. The clamp pulse is derived from the Y channel.
All outputs are capable of driving 2V
pp
, AC or DC coupled, into
either a single or dual video load. A single video load consists of
a series 75Ω impedance matching resistor connected to a ter-
minated 75Ω line. This presents a total of 150Ω of loading to the
part. A dual load would be two of these in parallel which would
present a total of 75Ω to the part. The gain of the Y, C and CV
signals can be selected for 0dB or 6dB with 1V
pp
input levels. All
video channels are clamped during sync to establish the appro-
priate output voltage reference levels.
The FMS6400 typical cutoff frequency is 7.1MHz. Option for a
lower cutoff frequency of 5MHz is available. Please refer to the
FMS6400-1 datasheet for further information.
Block Diagrams
S
gM
Sync Strip
Reference and
Timing
250mV
1
gM
250mV
4
8
6
5
2
7
YIN
CIN
ASEL
COUT
CVOU
YOUT
0 or
6dB
3
GND
0 or
6dB
