Vestigial Sideband Filters
VESTIGIAL SIDEBAND FILTERS
For Professional Applications
Replaces August 1992, version CT3447-1.2
DS5513-1.0 January 2002
Dynex Semiconductor's range of Surface Acoustic Wave
filters provide IF filtering for most current TV systems. The
filters are designed for use in TV modulators and transposers,
and are available without sound, with one sound channel, or
with stereo sound.
FEATURES
s
Filters for System B/G, I, M & K TV Standards
s
Linear Phase Characteristics
s
Low Amplitude and Group Delay Ripple
s
Sidelobe Levels Better Than 50dB
s
Hermetically Sealed Package
FILTER
DW1401-G
DW1404-G
DW1406-G
DW1408-G
DW1409-G
DW1411-G
DW2501-G
DW1502-I
DW1503-I
DW1505-I
DW9231-I
DW9232-I
DW1603-M
DW1605-M
DW1701-K
DW1702-K
SYSTEM
B/G
B/G
B/G
B/G
B/G
B/G
B/G
I
I
I
I
I
M
M
K
K
SOUND
None
1
None
Stereo
Stereo
None
1
1
1
1
None
None
1
None
1
REMARKS
PACKAGE STYLE
A
A
A
A
D
A
A
A
A
A
D
D
D
D
A
A
NICAM Sound Filter
NICAM Vision Filter
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Vestigial Sideband Filters
ELECTRICAL CHARACTERISTICS
Test Conditions (unless otherwise stated):
Temperature = +23°C
±2°C
Load and source impedances = 50Ω
SYSTEM B/G
FILTERS
Passband
Insertion Loss
Passband Ripple
Group Delay Ripple
Sound
DW1401-G
Typ
Max
DW1404-G
Typ
Max
DW1406-G
Typ
Max
DW1408-G
Typ
Max
DW1409-G
Typ
Max
DW1411-G
Typ
Max
DW2501-G
Typ
Max
Units
MHz
28
±0.5
50
dB
dB
ns p-p
-
34.4 to 39.4
29
±0.3
45
None
32
±0.5
60
33.65 to 38.9
29
±0.4
50
32
±0.5
60
34.4 to 39.4
30
±0.15
40
None
32
±0.2
50
33.15 to 38.9
29
32
±0.2
40
Stereo
33.65 to 39.15
29
32
±0.5
40
Stereo
33.15 to 39.65
24
33
±0.4
48
1 Channel
SYSTEM I
FILTERS
Passband
Insertion Loss
Passband Ripple
Group Delay Ripple
Sound
DW1502-I
Typ
Max
DW1503-I
Typ
Max
DW1505-I
Typ
Max
DW9231-I
Typ
Max
DW9232-I
Typ
Max
Units
MHz
dB
dB
ns p-p
-
34.25 to 41.25
29
±0.15
30
30
±0.25
40
33.4 to 40.9
29
±0.15
30
None
30
±0.2
40
29
30
±0.5
60
1 Channel
33.55 to 38.9
30
±0.3
40
1 Channel
32.1 to 33.0
30
±0.3
40
None
1 Channel
SYSTEM M
FILTERS
Passband
Insertion Loss
Passband Ripple
Group Delay Ripple
Sound
DW1603-M
Typ
Max
DW1605-M
Typ
Max
Units
MHz
dB
dB
ns p-p
-
SYSTEM K
FILTERS
Passband
Insertion Loss
Passband Ripple
Group Delay Ripple
Sound
DW1701-K
Typ
Max
DW1702-K
Typ
Max
Units
MHz
dB
dB
40
1 Channel
ns p-p
-
42.17 to 46.25
30
32
±0.5
50
None
40.75 to 46.5
26
29
±0.5
40
1 Channel
30.5 to 38.25
25
±0.5
40
None
26
29.0 to 38.5
32
±0.5
26
ABSOLUTE MAXIMUM RATINGS
Storage and Operating Temperature = -10°C to +70°C
Maximum Voltage = See Operating Note 1
Input Power = +20dBm
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Vestigial Sideband Filters
OPERATING NOTES
1. Coupling Capacitors
Although there is no DC path within the SAW filter it is advisable
to keep any applied DC voltage to <100mV.
Prolonged exposure to voltages in excess of this may adversely
affect the life of the filter. Short-term exposure to voltages up to
30 volts should not cause any problems.
2. Temperature Effects
The characteristics of SAW filters of this type behave in a simple
predictable manner with temperature. The temperature
coefficient of frequency is -90ppm/°C. For example the rejection
at 45°C and 40.15MHz will be the same as that at 25°C and
40.22MHz.
3. Mounting Precautions
In order to achieve the quoted rejections it is important to prevent
excessive direct breakthrough signals. Normal high frequency
precautions such as the use of continuous ground plane and
short component leads are necessary. It is most important that
the SAW filter is well grounded. All the earth leads on the
package should be connected to the ground plane by short
connections - plated through holes are ideal.
Direct breakthrough signals produce two main effects:
• Specified out of band rejections not achieved
• Passband ripple is excessive
A simple method to check that the grounding is adequate is to
connect the package directly to the ground plane temporarily,
and check that the frequency response does not change.
PLOTS
Fig.1 - DW1404-G
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