LTC1064
Low Noise, Fast, Quad
Universal Filter Building Block
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FEATURES
DESCRIPTION
The LTC®1064 consists of four high speed, low noise
switched-capacitor filter building blocks. Each filter build-
ing block, together with an external clock and three to five
resistors can provide various 2nd order functions like
lowpass, highpass, bandpass and notch. The center fre-
quency of each 2nd order function can be tuned with an
external clock, or a clock and resistor ratio. For Q ≤ 5, the
center frequency range is from 0.1Hz to 100kHz. For Q ≤
3, the center frequency range can be extended to 140kHz.
Up to 8th order filters can be realized by cascading all four
2nd order sections. Any classical filter realization (such as
Butterworth,Cauer,BesselandChebyshev)canbeformed.
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Four Filters in a 0.3-Inch Wide Package
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One Half the Noise of the LTC1059/LTC1060/
LTC1061 Devices
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Maximum Center Frequency: 140kHz
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Maximum Clock Frequency: 7MHz
Clock-to-Center Frequency Ratio of 50:1 and 100:1
Simultaneously Available
Power Supplies: ±2.375V to ±8V
Low Offsets
Low Harmonic Distortion
Customized Version with Internal Resistors
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Available
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A customized monolithic version of the LTC1064 includ-
ing internal thin film resistors can be obtained for high
volume applications. Consult LTC Marketing for details.
APPLICATIONS
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Anti-Aliasing Filters
Wide Frequency Range Tracking Filters
Spectral Analysis
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The LTC1064 is manufactured using Linear Technology’s
enhanced LTCMOSTM silicon gate process.
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Loop Filters
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTCMOS is a trademark of Linear Technology Corporation.
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TYPICAL APPLICATION
Clock-Tunable 8th Order Cauer Lowpass Filter with fCUTOFF up to 100kHz
13k
66.5k
R
H2
102k
Gain vs Frequency
PIN 12
22.1k
1
2
24
23
22
21
20
19
18
17
16
15
14
13
V
INV B
HPB/NB
BPB
INV C
HPC/NC
BPC
IN
10k
10k
0
–15
18.25k
10.7k
12.1k
17.4k
3
R
4
L2
LPB
LPC
26.7k
–30
5
SB
SC
–45
f
= 5MHz
CLK
6
–
AGND
V
RIPPLE = ±0.1dB
–8V
–60
0.1µF
LTC1064
7
+
8V
V
CLK
50/100
LPD
5MHz
8V
–75
0.1µF
10k
f
= 1MHz
8
CLK
SA
–90
RIPPLE = ±0.05dB
V
OUT
9
LPA
–105
–120
–135
41.2k
12.7k
14k
49.9K
11.5K
10
11
12
BPA
BPD
HPA/NA
INV A
HPD
1k
10k
100k
1M
(FROM
INV D
INPUT FREQUENCY (Hz)
R
, R )
H2 L2
121k
10k
1064 TA02
FOR f
CLK
= 5MHz, ADD C1 = 10pF BETWEEN PINS 4, 1
C2 = 10pF BETWEEN PINS 21, 24
WIDEBAND NOISE 140µV
RMS
1064 TA01
C3 = 27pF BETWEEN PINS 9, 12
1