FMS6406 Precision S-Video Filter with Summed Composite Output, Sound Trap, and Group Delay Compensation
August 2006
FMS6406
Precision S-Video Filter with Summed Composite
Output, Sound Trap, and Group Delay Compensation
Features
■
7.6MHz 5th-order Y,C filters with composite summer
■
14dB notch at 4.425MHz to 4.6MHz for sound trap
■
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■
■
■
■
■
■
■
■
■
Description
The FMS6406 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, an audio trap and
group delay compensation circuit. The audio trap removes
video information in the spectral location of the subsequent
RF audio carrier. The group delay circuit predistorts the
signal to compensate for the inherent receiver IF filter’s
group delay distortion.
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 feedback
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 75W impedance matching resistor
connected to a terminated 75W line, this presents a total
of 150W of loading to the part. A dual load would be two of
these in parallel which would present a total of 75W to the
part. The gain of the Y, C and CV signals is 6dB with 1V
pp
input levels. All video channels are clamped during sync
to establish the appropriate output voltage reference levels.
capable of handling stereo
50dB stopband attenuation at 27MHz on Y, C,
and CV outputs
Better than 0.5dB flatness to 4.2MHz on Y, C,
and CV outputs
Equalizer and notch filter for driving RF modulator with
group delay of -180ns
No external frequency selection components or clocks
< 5ns group delay on Y, C, and CV outputs
AC coupled inputs
AC or DC coupled outputs
Capable of PAL frequency for Y, C, CV
Continuous Time Low Pass Filters
<1.4% differential gain with 0.7° differential phase
on Y, C, and CV channels
Integrated DC restore circuitry with low tilt
Applications
■
Cable set-top boxes
■
Satellite set-top boxes
■
DVD players
Block Diagram
Sync Strip
Reference
and Timing
VCC
7
Y
IN
1
6dB
8
Y
OUT
gM
250mV
Σ
+
6
CV
OUT
EQ_NOTCH
+
gM
250mV
6dB
Notch
Group
Delay
2
C
IN
4
5
3
C
OUT
GND
Ordering Information
Part Number
FMS6406CS
FMS6406CSX
Package
SOIC-8
SOIC-8
Pb-Free
Yes
Yes
Operating Temp
Range
0°C to +70°C
0°C to +70°C
Packaging
Method
Tube
Tape and Reel
© 2006 Fairchild Semiconductor Corporation
www.fairchildsemi.com
FMS6406 Rev. 4.0.4
FMS6406 Precision S-Video Filter with Summed Composite Output, Sound Trap, and Group Delay Compensation
FMS6406 Pin Configuration
Y
IN
EQ_NOTCH
GND
C
IN
Pin Assignments
Pin#
Pin
Y
IN
Type
Input
Description
Luminance (Luma) Input: In a typical
system, this pin is connected to the
Luma or composite video output pin
from the external video encoder.
Composite video output to RF
modulator/driver.
Ground
Chrominance (Chroma) Input: In a
typical system, this pin is connected
to the Chroma output pin from the
external video encoder.
Filtered Chrominance Video Output
from the C
IN
channel.
Composite Video Output: This pin is
the sum of Y
OUT
and C
OUT
.
+5V supply.
Filtered Luminance Video Output
from the Y
IN
channel.
1
2
3
4
8
Y
OUT
V
CC
CV
OUT
C
OUT
1
FMS6406
8-pin
SOIC
7
6
5
2
3
4
EQ_NOTCH
GND
C
IN
Output
Input
Input
5
6
7
8
C
OUT
CV
OUT
V
CC
Y
OUT
Output
Output
Input
Output
© 2006 Fairchild Semiconductor Corporation
www.fairchildsemi.com
FMS6406 Rev. 4.0.4
FMS6406 Precision S-Video Filter with Summed Composite Output, Sound Trap, and Group Delay Compensation
Absolute Maximum Ratings
The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The
device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are
not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table defines the conditi-
ons for actual device operation.
Parameter
V
CC
Analog and Digital I/O
Output Channel - Any One Channel (Do Not Exceed)
Min.
-0.3
-0.3
Max.
6
V
CC
+ 0.3
100
Unit
V
V
mA
Notes:
Functional operation under any of these conditions is NOT implied. Performance and reliability are guaranteed only if operating conditions are not exceeded.
Reliability Information
Parameter
Junction Temperature
Storage Temperature Range
Lead Temperature (Soldering, 10s)
Thermal Resistance (q
JA
), JEDEC Standard Multi-layer
Test Boards, Still Air
115
-65
Min.
Typ.
Max.
150
+150
300
Unit
°C
°C
°C
°C/W
Recommended Operating Conditions
Parameter
Operating Temperature Range
V
CC
Range
GND
Min
0
+4.75
Typ
+5.0
0
Max
70
+5.25
Unit
°C
V
V
© 2006 Fairchild Semiconductor Corporation
www.fairchildsemi.com
FMS6406 Rev. 4.0.4
FMS6406 Precision S-Video Filter with Summed Composite Output, Sound Trap, and Group Delay Compensation
Electrical Characteristics
T
c
= 25°C, V
i
= 1V
pp
, V
CC
= 5V, all inputs AC-coupled with 0.1μF, all outputs are AC-coupled with 220μF into
150Ω, referenced to 400kHz; unless otherwise noted.
Symbol Parameter
I
CC
AV
YCCV
AV
EQ
C
sync
Y
sync
CV
sync
EQ
sync
T
CLAMP
f
FLAT
f
C
f
SB
V
i
I
SC
dG
dq
THD
X
TALK
PSRR
SNR
Supply Current
1
Low Frequency Gain (Y
OUT
, C
OUT
, CV
OUT
)
1
Low Frequency Gain (EQ_NOTCH)
1
C
OUT
Output Level (during Sync)
1
Y
OUT
Output Level (during Sync)
1
CV
OUT
Output Level (during Sync)
1
EQ_NOTCH Output Level (during Sync)
1
Clamp Response Time (Y Channel)
Gain Flatness to 4.2MHz
2
(Y
OUT
, C
OUT
, CV
OUT
)
-3dB Bandwidth
1
Stopband Attenuation
1
(Y
OUT
, C
OUT
, CV
OUT
)
Input Signal Dynamic Range
Output Short Circuit Current
4
(Any One Channel)
Differential Gain
2
Differential Phase
2
Output Distortion (All Channels)
Crosstalk (Channel-to-Channel)
PSRR (All Channels)
SNR Y, C Channel
2
SNR CV Channel
2
SNR EQ_NOTCH Channel
2
t
pd
GD
t
SKEW
t
CLGCV
t
CLDCV
GD
EQ
t
CLGEQ
t
CLDEQ
dG
EQ
dq
EQ
MCF
AV
PK
Atten1
Atten2
Atten3
t
PASS
Propagation Delay (Y, C, CV)
Group Delay (Y, C, CV)
2
Skew Between Y
OUT
and C
2
OUT
Conditions
V
CC
no load
at 400kHz
at 400kHz
Sync present on Y
IN
(after 6dB gain)
Sync present on Y
IN
(after 6dB gain)
Sync present on Y
IN
(after 6dB gain)
Sync present on Y
IN
(after 6dB gain)
Settled to within 10mV
Min
50
5.8
5.7
1.0
Typ Max Units
80
6.0
6.0
1.1
0.35
0.35
0.35
5
110
6.2
6.4
1.3
0.5
0.5
0.5
0.5
mA
dB
dB
V
V
V
V
ms
dB
MHz
dB
V
pp
mA
3
1.5
%
°
%
dB
dB
dB
dB
dB
ns
5
2
102
10
-165
105
-165
1
0.75
0.5
0.5
ns
ns
%
ns
ns
%
ns
%
%
dB
dB
dB
dB
dB
35
ns
-0.5
Y, C, CV Channels
at 27MHz
All Channels/AC coupled
Y, C, CV, EQ_NOTCH to GND
Y, C, CV
Y, C, CV
V
OUT
= 1.8V
pp
at 3.58MHz
at 3.58MHz
DC
NTC-7 weighting 4.2MHz lowpass
NTC-7 weighting 4.2MHz lowpass
NTC-7 weighting 4.2MHz lowpass
at 400kHz
at 3.58MHz (NTSC)
at 1MHz
f = 3.58MHz (ref to Y
IN
at 400kHz)
f = 3.58MHz (ref to Y
IN
at 400kHz)
f = 3.58MHz (ref to Y
IN
at 400kHz)
f = 3.58MHz (ref to Y
IN
at 400kHz)
f = 3.58MHz (ref to Y
IN
at 400kHz)
EQ_NOTCH Channel
EQ_NOTCH Channel
EQ_NOTCH from 400kHz to 3.75MHz
EQ_NOTCH from >3.75MHz to 4.2MHz
EQ_NOTCH at 4.425MHz
EQ_NOTCH at 4.5MHz
EQ_NOTCH at 4.6MHz
f = 400kHz to f = 3MHz
-0.5
-0.5
14
20
14
-35
-5
-2
98
-10
-195
95
-195
70
70
65
6.7
40
0
7.6
50
1.4
85
1.4
0.7
0.3
-50
50
75
75
70
112
0
0
100
0
-180
100
-180
0.3
0.3
0
0
Chroma-Luma Gain CV
OUT1
Chroma-Luma Delay CV
OUT1
Group Delay EQ_NOTCH
1
Chroma-Luma Gain EQ_NOTCH
1
Chroma-Luma Delay EQ_NOTCH
1
Differential Gain
2
Differential Phase
2
Modulator Channel Flatness
1,3
Gain Peaking
1
Notch Attenuation 1
1
Notch Attenuation 2
1
Notch Attenuation 3
1
Passband Group Delay, EQ_NOTCH
1
Notes:
1. 100% tested at 25°C.
2. Guaranteed by characterization.
3. Tested down to 400kHz, but guaranteed by design to 200kHz.
4. Sustained short circuit protection limited to 10 seconds.
© 2006 Fairchild Semiconductor Corporation
4
www.fairchildsemi.com
FMS6406 Rev. 4.0.4
FMS6406 Precision S-Video Filter with Summed Composite Output, Sound Trap, and Group Delay Compensation
Typical Performance Characteristics
T
c
= 25°C, V
i
= 1V
pp
, V
CC
= 5V, all inputs AC-coupled with 0.1μF, all outputs are AC-coupled with 220μF into
150Ω, referenced to 400kHz; unless otherwise noted.
10
0
-10
12
140
120
100
1
-20
-30
-40
-50
Mkr Frequency
Ref
400kHz
1
2
3
6.53MHz
7.87MHz
27MHz
Gain
6dB
Delay (ns)
30
Gain (dB)
80
60
40
20
0
400kHz
1 = 8.2MHz (111.35ns)
-60
400kHz
f
SB
= Gain
(ref)
– Gain
(3)
= 50.66dB
-3dB BW
-44.66dB
-1dB BW
3
5
10
15
20
25
5
10
15
20
25
30
Figure . Frequency Response Y
OUT
10
0
-10
12
Frequency (MHz)
Figure . Group Delay vs. Frequency Y
OUT
140
120
100
1
Frequency (MHz)
-20
-30
-40
-50
Mkr Frequency
Ref
400kHz
1
2
3
6.68MHz
7.87MHz
27MHz
Gain
6dB
Delay (ns)
30
Gain (dB)
80
60
40
20
0
400kHz
1 = 8.2MHz (111.16ns)
-60
400kHz
f
SB
= Gain
(ref)
– Gain
(3)
= 50.41dB
-3dB BW
-44.41dB
-1dB BW
3
5
10
15
20
25
5
10
15
20
25
30
Frequency (MHz)
Frequency (MHz)
Figure . Frequency Response C
OUT
10
0
-10
12
Figure 4. Group Delay vs. Frequency C
OUT
140
120
100
1
-20
-30
-40
-50
Mkr Frequency
Ref
400kHz
1
2
3
6.53MHz
7.72MHz
27MHz
Gain
-1dB BW
6dB
3
Delay (ns)
30
Gain (dB)
80
60
40
20
0
400kHz
1 = 8.2MHz (112.84ns)
-60
400kHz
f
SB
= Gain
(ref)
– Gain
(3)
= 49.49dB
-3dB BW
-43.49dB
5
10
15
20
25
5
10
15
20
25
30
Frequency (MHz)
Frequency (MHz)
Figure . Frequency Response CV
OUT
Figure 6. Group Delay vs. Frequency CV
OUT
© 2006 Fairchild Semiconductor Corporation
www.fairchildsemi.com
FMS6406 Rev. 4.0.4
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