LTC1064-2
Low Noise, High Frequency,
8th Order Butterworth Lowpass Filter
FEATURES
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DESCRIPTIO
8th Order Filter in a 14-Pin Package
140kHz Maximum Corner Frequency
No External Components
50:1 and 100:1 Clock to Cutoff Frequency Ratio
80µV
RMS
Total Wideband Noise
0.03% THD or Better
Operates from
±2.37V
to
±8V
Power Supplies
The LTC
®
1064-2 is a monolithic 8th order lowpass
Butterworth filter, which provides a maximally flat pass-
band. The attenuation slope is –48dB/octave and the
maximum attenuation is in excess of 80db. An external
TTL or CMOS clock programs the filter’s cutoff frequency.
The clock to cutoff frequency ratio is 100:1 (Pin 10 at
V
–
) or 50:1 (Pin 10 at V
+
). The maximum cutoff frequency
is 140kHz. No external components are needed.
The LTC1064-2 features low wideband noise and low
harmonic distortion even for input voltages up to 3V
RMS
.
In fact the LTC1064-2 overall performance competes with
equivalent multiple op amp RC active realizations. The
LTC1064-2 is available in a 14-pin DIP or 16-pin surface
mounted SW package. The LTC1064-2 is fabricated using
LTC’s enhanced analog CMOS Si-gate process.
The LTC1064-2 is pin compatible with the LTC1064-1.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
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Antialiasing Filters
Smoothing Filters
Tracking High Frequency Lowpass Filters
TYPICAL APPLICATIO
8th Order Clock Sweepable
Lowpass Butterworth Filter
1
14
OUT C
LTC1064-2
2
13
NC
V
IN
NC
3
8V
4
5
6
7
V
OUT
/V
IN
(dB)
Measured Frequency Response
0
V
S
=
±7.5V
–15
–30
AGND
V
+
AGND
NC
R
IN
A
V
–
f
CLK
50/100
V
OUT
NC
12
11
10
9
8
–8V
CLOCK = 5MHz
–45
–60
–75
–90
–105
1064 TA01a
0
100
NOTE: THE POWER SUPPLIES SHOULD BE BYPASSED BY A 0.1µF
CAPACITOR CLOSE TO THE PACKAGE. THE NC PINS 1, 6, 8,
AND 13 SHOULD BE PREFERABLY GROUNDED.
U
200 300 400 500
FREQUENCY (kHz)
600
700
1064-2 TA01b
U
U
10642fa
1
LINER [ LINEAR TECHNOLOGY ]
