LTC1059
1
1059fd
■
Sinewave Oscillators
■
Sweepable Bandpass/Notch Filters
■
Full Audio Frequency Filters
■
Tracking Filters
■
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
High Performance
Switched Capacitor Universal Filter
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.
Wide Range 2nd Order Bandpass/Notch Filter with Q = 10
1059 TA01a
1
2
3
4
5
6
7
14
13
12
11
10
9
8
–8V
8V
LTC1059
NOTCH OUT
BP OUT
50k
50k
7.15k
T
2
L CLOCK IN ≤ 2MHz
V
IN
DC-200kHz
BP
N/AP/HP
INV1
S1
S
A
V
+
LSh
LP
V
02
INV2
AGND
V
–
50/100/HOLD
CLK
TYPICAL APPLICATIO
U
APPLICATIO S
U
FEATURES
DESCRIPTIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
LTCMOS trademark of Linear Technology Corporation.
Center Frequency and Q Error
IDEAL CENTER FREQUENCY (kHz)
0
CENTER FREQUENCY ERROR NORMALIZED
TO 5kHz MEASUREMENT (%)
10
20
25 45
1058 TA01b
515
30
35
40
1.2
1.0
0.8
0.6
0.4
0.2
0
30
25
20
15
10
5
0
T
A
= 25°C
CLOCK
CENTER FREQUENCY
35.35
1
=
CENTER
FREQUENCY
ERROR
Q ERROR
DEVIATION FROM IDEAL Q OF 10 (%)
