LTC1164-5 Datasheet, PDF (1/16 Pages) Linear Technology – Low Power 8th Order Pin Selectable Butterworth or Bessel Lowpass Filter

FEATURES
■ _{Pin Selectable Butterworth or Bessel Response}
■ _{4mA Supply Current with ±5V Supplies}
■ _{fCUTOFF up to 20kHz}
■ _{100µVRMS Wideband Noise}
■ _{THD < 0.02% (50:1, VS = ±7.5V, VIN = 2VRMS)}
■ _{Operates with a Single 5V Supply (1VRMS Input}
Range)
■ _{60µVRMS Clock Feedthrough (Single 5V Supply)}
■ _{Operates up to ±8V Supplies}
■ _{TTL/CMOS-Compatible Clock Input}
■ _{No External Components}
■ _{Available in 14-Pin DIP and 16-Pin SO Wide}
Packages
U
APPLICATIO S
■ _{Anti-Aliasing Filters}
■ _{Battery-Operated Instruments}
■ _{Telecommunications Filters}
■ _{Smoothing Filters}
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
LTC1164-5
Low Power 8th Order
Pin Selectable Butterworth
or Bessel Lowpass Filter
DESCRIPTIO
The LTC^®1164-5 is a monolithic 8th order filter; it approxi-
mates either a Butterworth or a Bessel lowpass response.
The LTC1164-5 features clock-tunable cutoff frequency
and low power consumption (4.5mA with ±5V supplies
and 2.5mA with single 5V supply).
Low power operation is achieved without compromising
noise or distortion performance. With ±5V supplies and
10kHz cutoff frequency, the operating signal-to-noise
ratio is 86dB and the THD throughout the passband is
0.015%. Under the same conditions, a 77dB signal-to-
noise ratio and distortion is obtained with a single 5V
supply while the clock feedthrough is kept below the noise
level. The maximum signal-to-noise ratio is 92dB.
The LTC1164-5 approximates an 8th order Butterworth
response with a clock-to-cutoff frequency ratio of 100:1
(Pin 10 to V ^–) or 50:1 double-sampled (Pin 10 to V ⁺ and
Pin 1 shorted to Pin 13). Double-sampling allows the input
signal frequency to reach the clock frequency before any
aliasing occurrence. An 8th order Bessel response can
also be approximated with a clock-to-cutoff frequency
ratio of 140:1 (Pin 10 to ground). With ±7.5V supply, ±5V
supply and single 5V supply, the maximum clock fre-
quency of the LTC1164-5 is 1.5MHz, 1MHz and 1MHz
respectively. The LTC1164-5 is pin-compatible with the
LTC1064-2 and LTC-1064-3.
TYPICAL APPLICATIO
Butterworth 20kHz Anti-Aliasing Filter
1
14
V_IN
2
13
3
12
–8V
WIDEBAND NOISE = 110µV_RMS
8V
4 _LTC1164-5 11
5
10
CLK = 1MHz ^{THD IN PASSBAND < 0.02% AT VIN = 2VRMS}
NOTE: THE CONNECTION FROM PIN 7 TO PIN 14
TO V⁺
SHOULD BE MADE UNDER THE PACKAGE.
NC
6
7
9
V_OUT
FOR 50:1 OPERATION CONNECT PIN 1 TO PIN 13
AS SHOWN. FOR 100:1 OR 150:1 OPERATION PINS 1
8
AND 13 SHOULD FLOAT. THE POWER SUPPLIES
SHOULD BE BYPASSED BY A 0.1µF CAPACITOR AS
1164-5 TA01
CLOSE TO THE PACKAGE AS POSSIBLE.
0
–10
– 20
– 30
– 40
– 50
– 60
– 70
– 80
1
Frequency Response
10
FREQUENCY (kHz)
100
1164-5 TA02
11645fc
1