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FMS6408
Features
Triple Video Filter Driver for RGB and YUV Signals
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 2V
pp
, AC or DC coupled,
into either a single (150
Ω
) or dual (75
Ω
) 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).
• 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
IN
MUX
(A/B)
BYPASS (BYPASS/FILTER)
YINA
YINB
8MHz
*
6d
B
YOUT
gM
250mV
Sync Processing
UINA
UINB
8MHz
*
6d
B
UOUT
gM
250mV or
1.125V *
VINA
VINB
8MHz
*
6d
B
VOUT
gM
* Factory Selected Clamp
and Peaking Levels
250mV or
1.125V *
REV. 2C August 31, 2004
DATA SHEET
FMS6408
Electrical Specifications
(T
C
= 25˚C, V
i
= 1V
pp
, V
CC
= 5.0V, all inputs AC coupled with 0.1
µ
F, all outputs AC coupled with 220
µ
F into 150
Ω
,
referenced to 400kHz, 0dB peaking option; unless otherwise noted)
Symbol
I
CC
V
i
V
il
V
ih
V
CLAMP
PSRR
Parameter
Supply Current
1
Input Voltage Max
Digital Input Low
1
Digital Input High
1
Clamp Voltage
2
Power Supply Rejection Ratio
Bypass, A_NB
Bypass, A_NB
YUV/RGB/CV Inputs
PbPr/C Inputs
DC
0
2.0
250
1.125
-40
Conditions
V
CC
no load
Min
Typ
52
1.4
0.8
V
CC
Max Units
86
mA
V
pp
V
V
mV
V
dB
AC Electrical Specifications
(T
C
= 25˚C, V
i
= 1V
pp
, V
CC
= 5.0V, all inputs AC coupled with 0.1
µ
F, all outputs AC coupled with 220
µ
F into 150
Ω
,
referenced to 400kHz, 0dB peaking option; unless otherwise noted)
Symbol
A
PB
AV
LF
∆
AV
HF
Parameter
Passband Response
1
Delta High Frequency at 5MHz
(All Channels)
3
Conditions
4.2MHz
0dB Peaking Option
0.4dB Peaking Option
0.9dB Peaking Option
1.3dB Peaking Option
f
C
f
SBh
dG
d
θ
THD
SNR
H
DIST
V
DIST
t
pd
GD
t
SKEW
A
V(match)
T
CLAMP
X
TALK
IN
MUXISO
f
1dBWB
-3dB Bandwidth
Stopband Rejection (All Channels)
1
Differential Gain
Differential Phase
Total Harmonic Distortion
Line-Time Distortion
Field-Time Distortion
Propagation Delay (All Channels)
Group Delay (All Channels)
t
pd
Skew Between Any 2 Channels
Channel Gain Matching
1
Crosstalk (Channel-to-Channel)
Input Mux Isolation
Bypass Mode -1dB Bandwidth
All Channels
at 27MHz
All Channels
All Channels
at 3.58MHz
18
µ
s, 100 IRE Bar
130 Lines, 18
µ
s, 100 IRE Bar
400kHz
to 3.58MHz (NTSC)
at 400kHz
400kHz
at 1.0MHz
at 1.0MHz
1.4V
pp
Output All Channels
48
Min
-0.5
5.6
Typ
0
5.9
0.3
0.7
1.2
1.6
7.6
52
0.2
0.5
0.2
75
TBD
TBD
65
14
2
0
5
-65
-85
25
5
6.2
Max Units
dB
dB
dB
dB
dB
dB
MHz
dB
%
°
%
dB
Low Frequency Gain (All Channels)
1
at 400kHz
SNR All Channels (NTC7 Weighted) 4.2MHz Lowpass, 100kHz Highpass
%
%
ns
ns
ns
%
ms
dB
dB
MHz
Clamp Response Time (All Channels) Settled to 10mV, Initial Condition 0V
Notes
1. 100% tested at 25°C.
2. Mode selection for YUV/RGB vs. PbPr/YC vs. YC CV operation based on factory programming
3. Peaking Options boost gain by 0dB, 0.4dB, 0.9dB, or 1.3dB from 4.2MHz to 5MHz based on factory programming
2
REV. 2C August 31, 2004
FMS6408
DATA SHEET
Factory Programming Options
(See Ordering Information Table on Page 9 for current options)
Part Name
FMS6408-1
FMS6408-2
FMS6408-3
FMS6408-4
FMS6408-5
FMS6408-6
FMS6408-7
FMS6408-8
FMS6408-9
FMS6408-10
FMS6408-11
FMS6408-12
Part Number
FMS6408MTC141_NL
FMS6408MTC142_NL
FMS6408MTC143_NL
FMS6408MTC144_NL
FMS6408MTC145_NL
FMS6408MTC146_NL
FMS6408MTC147_NL
FMS6408MTC148_NL
FMS6408MTC149_NL
FMS6408MTC1410_NL
FMS6408MTC1411_NL
FMS6408MTC1412_NL
Clamping
Mode
YPbPr/YC
YPbPr/YC
YPbPr/YC
YPbPr/YC
YUV/RGB
YUV/RGB
YUV/RGB
YUV/RGB
YC/CV
YC/CV
YC/CV
YC/CV
Peaking
Mode (dB)
0
0.4
0.9
1.3
0
0.4
0.9
1.3
0
0.4
0.9
1.3
Y
OUT
Level
(mV)
250
250
250
250
250
250
250
250
250
250
250
250
U
OUT
Level
(V)
1.125
1.125
1.125
1.125
250
250
250
250
1.125
1.125
1.125
1.125
V
OUT
Level
(V)
1.125
1.125
1.125
1.125
250
250
250
250
250
250
250
250
Note
These factory programming options allow a single die to be configured for multiple operating modes.
Absolute Maximum Ratings
(beyond which the device may be damaged)
Parameter
V
CC
Analog and Digital
Output Current Any One Channel (Do not exceed)
Input Source Resistance (R
S
)
Min
-0.3
-0.3
Max
6
V
CC
+ 0.3
50
300
Units
V
V
mA
Ω
Note
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 (
θ
JA
),
JEDEC Standard Multi-layer Test Boards, Still Air
90
-65
Min
Typ
Max
+150
+150
+300
Units
°C
°C
°C
°C/W
Recommended Operating Conditions
Parameter
Temperature Range
V
CC
Range
Min
0
+4.75
+5.0
Typ
Max
70
+5.25
Units
°C
V
REV. 2C August 31, 2004
3
DATA SHEET
FMS6408
Typical Performance Characteristics
(T
C
= 25˚C, V
i
= 1V
pp
, V
CC
= 5.0V, all inputs AC coupled with 0.1
µ
F, all outputs AC coupled with 220
µ
F into 150
Ω
,
referenced to 400kHz, 0dB peaking option; unless otherwise noted)
SD Frequency Response
10
0
1
2
SD Group Delay vs. Frequency
60
40
Gain (10dB/div)
-20
Mkr
Freq.
Gain
Delay (ns)
-10
20
0
-20
-40
1
-30
-40
-50
Ref
400kHz 6dB
1 6.91MHz -1dB BW
2
3
7.8MHz
27MHz
-3dB BW
-43.24dB
3
f
SBSD
= Gain
(ref)
– Gain
(3)
= 49.24dB
1 = 7.6MHz (31.88ns)
-60
30
400kHz
5
10
15
20
25
30
400kHz
5
10
15
20
25
Frequency (MHz)
SD Noise vs. Frequency
-50
-60
0.2
Frequency (MHz)
SD Differential Gain
NTSC
Differential Gain (%)
0
-0.2
-0.4
-0.6
-0.8
-70
Noise (dB)
-80
-90
-100
-110
-120
0
1.0
2.0
3.0
4.0
5.0
6.0
Min = -0.61
Max = 0.00
ppMax = 0.61
1st
2nd
3rd
4th
5th
6th
Frequency (MHz)
SD Differential Phase
0.05
7
Bypass Mode Frequency Response
V
O
= 1.4
pp
Differential Phase (deg)
0
6
Gain (1dB/div)
5
1
-0.05
-0.10
-0.15
-0.20
1st
2nd
3rd
4th
5th
6th
4
2
3
2
1
0
400kHz 5
10
15
20
25
30
35
40
45
Mkr
Ref
1
2
Frequency
400kHz
28.75MHz
36.94MHz
Gain
6dB
-1dB BW
-3dB BW
Min = -0.13
Max = 0.00
ppMax = 0.13
Frequency (MHz)
Bypass Mode Group Delay vs. Freq.
16
14
12
Delay (ns)
10
8
6
4
2
1 = 25MHz (8.99ns)
1
0
400kHz 5
10
15
20
25
30
35
40
45
Frequency (MHz)
4
REV. 2C August 31, 2004
FMS6408
DATA SHEET
Pin Configuration
Pin#
Y
INA
U
INA
V
INA
Pin
Y
INA
U
INA
V
INA
GND
Y
INB
U
INB
V
INB
IN
MUX
(A/B)
V
OUT
GND
U
OUT
BYPASS
(Bypass/Filter)
Y
OUT
V
CC
Type
Input
Input
Input
Input
Input
Input
Input
Input
Output
Input
Output
Input
Output
Input
Description
Y (Luminance) or Green input A, must be
connected to a signal which includes sync
U or Blue input A
V or Red input A
Must be tied to ground, do not float
Y (Luminance) or Green input B, must be
connected to a signal which includes sync
U or Blue input B
V or Red input B
Mux select, A = ‘1’, B = ‘0’, must be
externally tied high or low
V or Red output
Must to be tied to ground, do not float
U or Blue output
Filter bypass, BYPASS = ‘1’, FILTER = ‘0’,
must be externally tied high or low
Y or Green output
+5V supply
1
2
3
4
5
6
7
14
V
CC
Y
OUT
BYPASS
U
OUT
GND
V
OUT
1
2
3
4
5
6
FMS6408
14-pin
TSSOP
13
12
11
10
9
8
GND
Y
INB
U
INB
V
INB
IN
MUX
(A/B)
7
8
9
10
11
12
13
14
Functional Description
Introduction
This product is a three channel monolithic continuous time
video filter designed for reconstructing YUV, YC CV or
RGB signals from a video D/A source. Inputs should be AC
coupled while outputs can be either AC or DC coupled.
The reconstruction filters approximate a 5th order Butter-
worth response optimized for minimum overshoot and flat
group delay. This provides a maximally flat response in
terms of delay and amplitude. Each of the three outputs is
capable of driving 2V
pp
into 75Ω loads.
All channels are clamped during the sync interval to set the
appropriate dc output level. Sync tip clamping greatly reduces
the effective input time constant allowing the use of small
low cost input coupling capacitors. The input will settle to
10mV in 2ms for typical DC shifts present in the video signal.
In most applications the input coupling capacitors are 0.1µF.
The inputs typically sink 1uA of current during active video.
For YUV signals, this translates into a 2mV tilt in a horizon-
tal line at the Y output. During sync, the clamp restores this
leakage current by sourcing an average of 20µA over the
clamp interval. Any change in the coupling capacitor values
will affect the amount of tilt per line. Any reduction in tilt
will come with an increase in settling time.
Sync processing is based on the Y/G input channel in all
operating modes.
Inputs
The inputs will typically be driven by either a low impedance
source of 1V
pp
or the output of a 75Ω terminated line driven
by the output of a current DAC. In either case, the inputs
must be capacitively coupled to allow the sync-detect and
DC restore circuitry to operate properly.
Outputs
The outputs are low impedance voltage drivers which can
handle either a single or dual load. A single load consists of
a 75Ω series termination resistor feeding a 75Ω terminated
line for a total load at the part of 150Ω. Even when two loads
are present (75Ω) the driver will produce a full 2V
pp
signal
at its output pin. The driver can also be used to drive an AC
coupled single or dual load. When driving a dual load either
output will still function if the other output connection is
inadvertently shorted providing these loads are AC coupled.
REV. 2C August 31, 2004
5
单片机
