FMS6366_05 Datasheet, PDF (8/12 Pages) Fairchild Semiconductor – Selectable YPbPr HD/SD 4:2:2 Video Filter Driver

General Description
The FMS6366 offers comprehensive filtering for set top box or
DVD applications. This part consists of triple 4:2:2 6th order filters
with selectable 30/15MHz or 8/4MHz frequencies for YPbPr and
a dual 8MHz filter for YC with a composite summer. Two-to-one
multiplexers are provided on the triple filters as well as provisions
for auxiliary input to the composite channel. The triple filters are
intended for YPbPr signals. All channels accept DC coupled
ground-referenced 1V_pp signals. The filters output 2V_pp signals
into AC coupled terminated loads.
The FMS6366 is a next generation filter solution from Fairchild
Semiconductor addressing the expanding filtering needs for set
top boxes, and DVD players. The product provides selectable
4:2:2 HD/SD filtering on the YPbPr channels. Thus, the
FMS6366 addresses the requirement for a single set top box to
be compatible with a variety of resolution standards. Additionally,
the product provides additional filters for Y, C, and Composite
Video (CV) outputs. Multiplexers on the YPbPr and CV channels
provide further flexibility.
For DVD applications, the product provides filtering and output
drive amplification for 6 channels of outputs. These include Y1,
Pb, Pr, Y2, C, and CV outputs.
For Set top boxes, this product provides two channels of filtered
video with the flexibility of selectable high order filtering for multi-
ple resolution standards. Additional flexibility is provided by the
Y (Luma) and C (Chroma) filters with a composite summer.
All channels provide 6dB gain, accept 1V ground referenced
inputs, and drive AC coupled loads.
Functional Description
DC Levels
At any given time, the input signal’s DC levels must be between
0.0V and 1.3V to utilize the optimal headroom and to avoid clip-
ping at the outputs. The Y channels accept 1V_pp signals with the
sync tip at ground. The Pb, Pr and C channels should be cen-
tered around 0.5V. This will ensure that the filter will utilize the
optimal headroom and avoid clipping.
DC-Coupled Output Applications
The 220uF capacitor coupled with the 150Ω termination forms a
high pass filter that blocks the DC while passing the video fre-
quencies and avoiding tilt. Lower values such as 10uF cause
unacceptable tilt in the output signal. By AC coupling, the aver-
age DC level is zero. Thus, the output voltages of all channels
will be centered around zero.
DC coupling the output of the FMS6366 is allowable, but not
recommended. There are several trade-offs: The average DC
level on the outputs will be 2V. Each output will dissipate an
additional 40mW nominally. The application will need to accom-
modate a 1V DC offset sync tip. Also, it is recommended to limit
one 150Ω load per output.
The FMS6366 is specified to operate with output currents typi-
cally less than 50mA, more than sufficient for a dual (75Ω) video
load. Internal amplifiers are current limited to a maximum of
100mA and should withstand brief duration short circuit condi-
tions, however this capability is not guaranteed.
Driving Digital Pins
The FMS6366 digital inputs are compatible with most 3.3V and
5V logic. Verify that the V_ih and V_il are within the specified limits.
Applications
A typical application for the FMS6366 is shown in Figure 16.
DAC
A_NB
HD / N_SD
16
2
PbINA
RT = 37.5Ω
RSOURCE = RT
23
26
VCC
20
VCC
0.1μF
+5V
1μF
RT = 37.5Ω
3
PbINB
4
Y1INA
24
PrOUT
FMS6366
5
Y1INB
23
Y1OUT
75Ω
220μF
75Ω Video Cable
75Ω
75Ω
220μF
75Ω Video Cable
75Ω
RT = 37.5Ω
6
PrINA
7
PrINB
8
YC / N_AUX
9, 10, 15, 17
NC
RT = 37.5Ω
12
AUXIN
RT = 37.5Ω
14
Y2IN
22
PbOUT
75Ω
220μF
75Ω Video Cable
75Ω
21
Y2OUT
75Ω
220μF
75Ω Video Cable
75Ω
19
COUT
75Ω
0.1μF
75Ω Video Cable
75Ω
18
CVOUT
75Ω
220μF
75Ω Video Cable
75Ω
RT = 37.5Ω
13
CIN
VSS VSS VSS VSS
11 16 25 27
Figure 16. Typical Application Diagram
Digital Delay Compensation
FMS6366
Y
Luminance
Propagation
Delay
Chroma
Pr
8-10
A/D
Shift ^8-10
Register
8-10
A/D
Video
Processing
Pb
8-10
A/D
Figure 17. Digital Delay Compensation for
anti-alias 4:2:2 filters
www.fairchildsemi.com
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FMS6366 Rev. 2C