LTC1565-31
650kHz Continuous Time,
Linear Phase Lowpass Filter
FEATURES
s
s
s
s
s
s
s
s
s
DESCRIPTIO
7th Order, 650kHz Linear Phase Filter in an SO-8
Differential Inputs and Outputs
Operates on a Single 5V or a
±5V
Supply
Low Offset: 5mV Typical
75dB THD and SNR
78dB SNR
Shutdown Mode
Requires No External Components
Requires No External Clock Signal
APPLICATIO S
s
s
s
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CDMA Base Stations
Data Communications
Antialiasing Filters
Smoothing or Reconstruction Filters
Matched Filter Pairs
Replacement for LC Filters
The LTC
®
1565-31 is a 7th order, continuous time, linear
phase lowpass filter. The selectivity of the LTC1565-31,
combined with its linear phase and dynamic range, make it
suitable for filtering in data communications or data acqui-
sition systems. The filter attenuation is 36dB at 2× f
CUTOFF
and at least 72dB for frequencies above 3× f
CUTOFF
. Unlike
comparable LC filters, the LTC1565-31 achieves this selec-
tivity with a linear phase response in the passband.
With 5% accuracy of the cutoff frequency, the LTC1565-31
can be used in applications requiring pairs of matched filters,
such as transceiver I and Q channels. Furthermore, the
differential inputs and outputs provide a simple interface for
these wireless systems.
With a single 5V supply and a 2V
P-P
input, the LTC1565-31
features an impressive spurious free dynamic range of 75dB.
The maximum signal-to-noise ratio is 78dB and it is achieved
with a 2.5V
P-P
input signal.
The LTC1565-31 features a shutdown mode where power
supply current is typically less than 10µA.
For W-CDMA, 3G, CDMA 2000 and other cellular and
noncellular cutoff frequencies or single-ended I/O, please
contact LTC Marketing for additional information.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
Frequency Response
10
2.0
GAIN
1.9
1.8
1.7
1.6
DELAY
1.5
1.4
1.3
1.2
1.1
1.0
10
5
10
6
FREQUENCY (Hz)
0.9
10
7
1565 G01
Single 5V Supply, Differential 650kHz Lowpass Filter
V
IN+
V
IN–
1
2
+IN
–IN
+OUT
–OUT
8
7
V
OUT+
GAIN (dB)
V
OUT–
5V
5V
0.1µF
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
10
4
LTC1565-31
3
0.1µF
4
GND
V
–
6
V
+
5
SHDN
15645-31 TA01
U
DELAY (µs)
U
U
1
LINER [ LINEAR TECHNOLOGY ]
