LTC1063_09 Datasheet, PDF (1/16 Pages) Linear Technology – DC Accurate, Clock-Tunable 5th Order Butterworth Lowpass Filter

LTC1063
DC Accurate, Clock-Tunable
5th Order Butterworth
Lowpass Filter
FEATURES
■ _{Clock-Tunable Cutoff Frequency}
■ _{1mV DC Offset (Typical)}
■ _{80dB CMRR (Typical)}
■ _{Internal or External Clock}
■ _{50µVRMS Clock Feedthrough}
■ _{100:1 Clock-to-Cutoff Frequency Ratio}
■ _{95µVRMS Total Wideband Noise}
■ _{0.01% THD at 2VRMS Output Level}
■ _{50kHz Maximum Cutoff Frequency}
■ _{Cascadable for Faster Roll-Off}
■ _{Operates from ±2.375 to ±8V Power Supplies}
■ _{Self-Clocking with 1 RC}
■ _{Available in 8-Pin DIP and 16-Pin SO Wide Packages}
U
APPLICATIO S
■ _Audio
■ _{Strain Gauge Amplifiers}
■ _{Anti-Aliasing Filters}
■ _{Low Level Filtering}
■ _{Digital Voltmeters}
■ _{60Hz Lowpass Filters}
■ _{Smoothing Filters}
■ _{Reconstruction Filters}
, LTC and LT are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
DESCRIPTIO
The LTC^®1063 is the first monolithic filter providing both
clock-tunability, low DC output offset and over 12-bit DC
accuracy. The frequency response of the LTC1063 closely
approximates a 5th order Butterworth polynomial. With
appropriate PCB layout techniques the output DC offset is
typically 1mV and is constant over a wide range of clock
frequencies. With ±5V supplies and ±4V input voltage
range, the CMR of the device is 80dB.
The filter cutoff frequency is controlled either by an inter-
nal or external clock. The clock-to-cutoff frequency ratio is
100:1. The on-board clock is power supply independent,
and it is programmed via an external RC. The 50µV_RMS
clock feedthrough is considerably reduced over existing
monolithic filters.
The LTC1063 wideband noise is 95µV_RMS, and it can
process large AC input signals with low distortion. With
±7.5V supplies, for instance, the filter handles up to
4V_RMS (92dB S/N ratio) while the standard 1kHz THD is
below 0.02%; 80dB dynamic ranges (S/N +THD) is ob-
tained with input levels between 1V_RMS and 2.3V_RMS.
The LTC1063 is available in 8-pin miniDIP and 16-pin SO
wide packages. For a linear phase response, see LTC1065
data sheet.
TYPICAL APPLICATIO
2.5kHz 5th Order Lowpass Filter
V_IN** ¹
8
2
7
V_OUT
LTC1063
3
6
5V
– 5V
4
5
0.1µF
0.1µF ^*19.1k
200pF*
* SELF-CLOCKING SCHEME
** IF THE INPUT VOLTAGE CAN EXCEED V⁺,
CONNECT A SIGNAL DIODE BETWEEN PIN 1 AND V⁺.
1063 TA01
10
0
–10
– 20
– 30
– 40
– 50
– 60
– 70
– 80
– 90
1
Frequency Response
10
FREQUENCY (kHz)
100
1063 TA02
1063fa
1