LTC1059_15 Datasheet, PDF (1/8 Pages) Linear Technology – High Performance Switched Capacitor Universal Filter

LTC1059
High Performance
Switched Capacitor Universal Filter
FEATURES
■ _{All Filter Parameters Guaranteed Over Temperature}
■ _{Wide Center Frequency Range (0.1Hz to 40kHz)}
■ _{Low Noise, Wide Dynamic Range}
■ _{Guaranteed Operation for ±2.37V and ±5V Supply}
■ _{Low Power Consumption}
■ _{Guaranteed Clock-to-Center Frequency Accuracy of}
0.8%
■ _{Guaranteed Low Offset Voltages Over Temperature}
■ _{Very Low Center Frequency and Q Tempco}
■ _{Clock Input T}²_{L or CMOS Compatible}
■ _{Separate Highpass (or Notch or Allpass), Bandpass,}
Lowpass Outputs
U
APPLICATIO S
■ _{Sinewave Oscillators}
■ _{Sweepable Bandpass/Notch Filters}
■ _{Full Audio Frequency Filters}
■ _{Tracking Filters}
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTCMOS trademark of Linear Technology Corporation.
DESCRIPTIO
The LTC^®1059 consists of a general purpose, high perfor-
mance, active filter building block and an uncommitted op
amp. The filter building block together with an external
clock and 2 to 5 resistors can produce various 2nd order
functions which are available at its three output pins. Two
out of three always provide lowpass and bandpass func-
tions while the third output pin can produce notch or
highpass or allpass. The center frequency of these func-
tions can be tuned from 0.1Hz to 40kHz and is dependent
on an external clock or an external clock and a resistor
ratio. The filter can handle input frequencies up to 100kHz.
The uncommitted op amp can be used to obtain additional
allpass and notch functions, for gain adjustment or for
cascading techniques.
Higher than 2nd order filter functions can be obtained by
cascading the LTC1059 with the LTC1060 dual universal
filter or the LTC1061 triple universal filter. Any classical
filter realization (such as Butterworth, Cauer, Bessel and
Chebyshev) can be formed.
The LTC1059 can be operated with single or dual supplies
ranging from ±2.37V to ±8V (or 4.74V to 16V single
supply).
The LTC1059 is manufactured by using Linear Technology’s
enhanced LTCMOS^TM silicon gate process.
TYPICAL APPLICATIO
Wide Range 2nd Order Bandpass/Notch Filter with Q = 10
50k
V_IN ^50k
DC-200kHz
7.15k
8V
NOTCH OUT
BP OUT
1 _BP
LP ¹⁴
LTC1059
2 _{N/AP/HP V02} 13
3 _INV1
INV2 ¹²
4 _S1
AGND ¹¹
5 _SA
V^{– 10} –8V
6 _{V+ 50/100/HOLD} 9
7 _LSh
CLK ⁸
T²L CLOCK IN ≤ 2MHz
1059 TA01a
Center Frequency and Q Error
1.2
30
T_A = 25°C
1.0
CLOCK
= ^35.35
CENTER FREQUENCY 1
25
0.8
20
0.6
15
CENTER
FREQUENCY
0.4
ERROR
10
0.2
0
0
5
Q ERROR
0
5 10 15 20 25 30 35 40 45
IDEAL CENTER FREQUENCY (kHz)
1058 TA01b
1059fd
1