FMS6141 — Low-Cost, Single-Channel 4
th
-Order Standard Definition Video Filter Driver
December 2006
FMS6141
Low-Cost, Single-Channel 4
th
-Order
Standard Definition Video Filter Driver
Features
Single 4th-Order 8MHz (SD) Filter
Drives Single, AC- or DC-coupled, Video Loads
(2V
pp
, 150Ω)
Drives Dual, AC- or DC-coupled, Video Loads
(2V
pp
, 75
Ω)
Transparent Input Clamping
AC- or DC-Coupled Input
AC- or DC-Coupled Output
DC-Coupled Output Eliminates AC-Coupling
Capacitors
Single Supply
Robust 8kV ESD Protection
Lead-Free Packages: SOIC-8 or SC70-5
Description
The FMS6141 Low-Cost Video Filter is intended to
replace passive LC filters and drivers with a low-cost
integrated device. The 4th-order filter provides improved
image quality compared to typical 2nd or 3rd-order
passive solutions.
The FMS6141 may be directly driven by a DC-coupled
DAC output or an AC-coupled signal. Internal diode
clamps and bias circuitry may be used if an AC-coupled
input is required (see Application Information for details).
The FMS6141’s output can drive an AC- or DC-coupled
single (150
Ω)
or dual (75
Ω)
load. DC-coupling the
output removes the need for output coupling capacitors.
The input DC level is offset approximately +280mV at
the output (see Application Information for details).
Related Applications Notes
AN-6041 PCB Layout Considerations for Video
Filter / Drivers
AN-6024 FMS6xxx Product Series Understanding
Analog Video Signal Clamps, Bias, DC-Restore,
and AC or DC Coupling Methods
Applications
Cable Set-Top Boxes
Satellite Set-Top Boxes
DVD Players
HDTVs
Personal Video Recorders (PVR)
Video On Demand (VOD)
Functional Block Diagram
VIDEOIN
Transparent Clamp
2X
VIDEOOUT
8MHz, 4th-order
Figure 1. FMS6141 Block Diagram
© 2006 Fairchild Semiconductor Corporation
FMS6141 Rev. 1.0.1
www.fairchildsemi.com
FMS6141 — Low-Cost, Single-Channel 4
th
-Order Standard Definition Video Filter Driver
Ordering Information
Part Number
FMS6141CS
FMS6141CSX
FMS6141S5X
Package
SOIC-8
SOIC-8
SC70-5
Pb-Free
Yes
Yes
Yes
Operating
Temperature Range
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
Packing Method
Tube
Tape and Reel
Tape and Reel
Pin Configurations
VIN 1
N/C
GND
N/C
2
3
4
FMS6141
SOIC-8
8
7
6
5
VOUT
VCC
N/C
N/C
GND
GND
1
2
FMS6141
SC70-5
4
VOUT
5
VCC
VIN 3
Figure 2. FMS6141 SOIC-8
Figure 3. FMS6141 SC70
Pin Definitions
Pin #
1
2
3
4
5
6
7
8
Name
V
IN
N/C
GND
N/C
N/C
N/C
V
CC
V
OUT
Description
Video input
No connect
Must be connected to ground
No connect
No connect
No connect
+5V supply, do not float
Filtered video output
Table 2. SC70 Pin Definitions
Pin#
1
2
3
4
5
Name
GND
GND
V
IN
V
OUT
V
CC
Description
Must be connected to ground
Must be connected to ground
Video input
Filtered video output
+5V supply, do not float
Table 1. SOIC Pin Definitions
© 2006 Fairchild Semiconductor Corporation
FMS6141 Rev. 1.0.1
www.fairchildsemi.com
2
FMS6141 — Low-Cost, Single-Channel 4
th
-Order Standard Definition Video Filter Driver
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
conditions for actual device operation.
Parameter
DC Supply Voltage
Analog and Digital I/O
Output Current, Do Not Exceed
Min.
-0.3
-0.3
Max.
6.0
V
CC
+0.3
50
Unit
V
V
mA
Recommended Operating Conditions
Parameter
Operating Temperature Range
V
CC
Range
Min.
-40
4.75
Typ.
5.0
Max.
85
5.25
Unit
°C
V
ESD Information
Parameter
Human Body Model (HBM)
Charged Device Model (CDM)
Value
8
1.5
Unit
kV
kV
Reliability Information
Symbol
T
J
T
STG
T
L
Θ
JA
Junction Temperature
Storage Temperature Range
Lead Temperature (Soldering, 10s)
Thermal Resistance
(JEDEC Standard Multi-Layer Test Boards, Still Air)
SOIC-8
SC70-5
115
332
-65
Parameter
Min.
Typ.
Max.
150
150
300
Unit
°C
°C
°C
°C/W
°C/W
© 2006 Fairchild Semiconductor Corporation
FMS6141 Rev. 1.0.1
www.fairchildsemi.com
3
FMS6141 — Low-Cost, Single-Channel 4
th
-Order Standard Definition Video Filter Driver
DC Specifications
T
A
= 25°C, V
CC
= 5.0V, R
S
= 37.5Ω; input is AC coupled with 0.1µF; output is AC coupled with 220µF into a 150Ω
load; unless otherwise noted.
Symbol
I
CC
V
IN
PSRR
Parameter
Supply Current
(1)
Video Input Voltage Range
Power Supply Rejection Ratio
No load
Conditions
Referenced to GND if DC-
coupled
DC
Min.
Typ.
7
1.4
40
Max.
12
Unit
mA
V
pp
dB
Note:
1. 100% tested at 25°C.
AC Electrical Specifications
T
A
= 25°C, V
CC
= 5.0V, R
S
= 37.5Ω; input is AC coupled with 0.1µF; output is AC coupled with 220µF into a 150Ω
load; unless otherwise noted.
Symbol
AV
f
1dB
f
C
f
SB
dG
dφ
THD
SNR
t
pd
Parameter
Channel Gain
(1)
-1dB Bandwidth
(1)
-3dB Bandwidth
Attenuation (Stopband Reject)
Differential Gain
Differential Phase
Output Distortion (all channels)
Signal-to-Noise Ratio
Propagation Delay
Conditions
Min.
5.6
4.0
Typ.
6.0
6.5
7.7
42
0.4
0.4
Max.
6.4
Unit
dB
MHz
MHz
dB
%
°
%
dB
ns
f = 27MHz
V
OUT
= 1.8V
pp
, 1MHz
NTC-7 weighting; 100kHz to
4.2MHz
Delay from input to output,
4.5MHz
0.4
75
55
Note:
1. 100% tested at 25°C.
© 2006 Fairchild Semiconductor Corporation
FMS6141 Rev. 1.0.1
www.fairchildsemi.com
4
FMS6141 — Low-Cost, Single-Channel 4
th
-Order Standard Definition Video Filter Driver
Application Information
Input Considerations
The FMS6141 Low-Cost Video Filter provides 6dB (2X)
gain from input to output. The device provides an
internal diode clamp to support AC-coupled input
signals. In this configuration, a 0.1µF ceramic capacitor
is used to AC couple the input signal. If the input signal
does not go below ground, the clamp is inactive; but if
the input signal goes below ground, the clamp circuitry
sets the bottom of the sync tip (or lowest voltage) to just
below ground. The input level set by the clamp,
combined with the internal DC offset, keeps the output
signal within an acceptable range. This clamp feature
also allows the FMS6141’s input to be directly driven
(DC-coupled) by a ground referenced DAC output.
Figure 4 shows typical DC voltage levels for the input
and output signals when driven by a DC-coupled DAC
output or an AC-coupled and clamped Y, CV signal.
1.0 -> 1.02V
0.65 -> 0.67V
0.3 -> 0.32V
0.0 -> 0.02V
Vin
2.28V
1.58V
0.88V
0.28V
Vout
Figure 4. Typical DC Voltage Levels
Output Considerations
The FMS6141’s output is DC offset from the input by
280mv; therefore V
OUT
= 2 • V
IN
+280mv. This offset is
required to obtain optimal performance from the output
driver and is held at the minimum value to decrease the
standing DC current into the load. Since the FMS6141
has a 2x (6dB) gain, the output is typically connected via
a 75Ω-series, back-matching resistor followed by the
75Ω video cable. Due to the inherent divide-by-two of
this configuration, the blanking level at the load of the
video signal is always less than 1V. When AC-coupling
the output, ensure that the coupling capacitor of choice
passes the lowest frequency content in the video signal
and that line time distortion (video tilt) is kept as low as
possible. The selection of the coupling capacitor is a
function of the subsequent circuit’s input impedance and
the leakage current of the input being driven. To obtain
the highest quality output video signal, the series
termination resistor must be placed as close to the
device’s output pin as possible. This greatly reduces
parasitic capacitance and inductance effects on the
FMS6141’s output driver. The distance from the device’s
pin to the series termination resistor should be no
greater than 0.1 inches, as shown in Figure 5.
Figure 5. Resistor Placement
© 2006 Fairchild Semiconductor Corporation
FMS6141 Rev. 1.0.1
www.fairchildsemi.com
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
