Datasheet

LTC1064-3
1
10643fa
FEATURES
APPLICATIO S
U
DESCRIPTIO
U
TYPICAL APPLICATIO
U
■
Antialiasing Filters
■
Smoothing Filters
■
Tracking High Frequency Lowpass Filters
■
8th Order Filter in a 14-Pin Package
■
95kHz Maximum Corner Frequency
■
No External Components
■
75:1, 150:1 and 120:1 Clock to Cutoff Frequency
Ratio
■
60µV
RMS
Total Wideband Noise
■
0.03% THD or Better
■
Operates from ±2.37V to ±8V Power Supplies
■
Low Total Output DC Offset
Low Noise, High Frequency,
8th Order Linear Phase Lowpass Filter
The LTC
®
1064-3 is a monolithic 8th order lowpass Bessel
filter, which provides a linear phase response over its
entire passband. An external TTL or CMOS clock pro-
grams the filter’s cutoff frequency. The clock to cutoff
frequency ratio is 75:1 (Pin 10 at V
+
) or 150:1 (Pin 10 at
V
–
) or 120:1 (Pin 10 at GND). The maximum cutoff
frequency is 95kHz. No external components are needed.
The LTC1064-3 features low wideband noise and low
harmonic distortion even for input voltages up to 3V
RMS
.
In fact the LTC1064-3 overall performance competes with
equivalent multiple op amp RC active realizations. The
LTC1064-3 is available in a 14-pin DIP or 16-pin surface
mounted SOL package. The LTC1064-3 is fabricated using
LTC’s enhanced analog CMOS Si-gate process.
The LTC1064-3 is pin compatible with the LTC1064-1,
LTC1064-2 and LTC1064-4.
8th Order Clock Sweepable Lowpass Bessel Filter Measured Frequency Response
LTC1064-3
1
2
3
4
5
6
7
14
13
12
11
10
9
8
OUT C
NC
V
–
f
CLK
75/150
V
OUT
NC
V
+
NC
V
IN
AGND
AGND
NC
INV A
1064 TA01a
NOTE: THE POWER SUPPLIES SHOULD BE BYPASSED BY A 0.1µF
OR LARGER CAPACITOR CLOSE TO THE PACKAGE. THE CONNECTI0N
BETWEEN PIN 7 AND PIN 14 SHOULD BE MADE UNDER THE IC PACKAGE.
CLOCK = 7MHz
V
+
–8V
8V
0.1µF
0.1µF
V
IN
V
OUT
FREQUENCY (kHz)
10
0
–15
–30
–45
–60
–75
–90
–105
1064-3 TA01b
100 1000
V
OUT
/V
IN
(dB)
V
S
= ±7.5V, f
CLK
= 7MHz, PIN 10 TO V
+
,
f
–3dB
= 95kHz, GROUP DELAY = 6µs
, LTC and LT are registered trademarks of Linear Technology Corporation.