16
LT1632/LT1633
sn1632 16323fs
LT/TP 0998 4K • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1998
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear-tech.com
TYPICAL APPLICATION
U
–
+
A2
1/2 LT1632
V
IN
V
OUT
1632/33 F05
5V
5V
R2
1k
R9
1k
R8
5k
R11
10k
R10
10k
R6
1k
R1
500Ω
R5
1k
R7
1k
R
1.62k
R
1.62k
C
1000pF
C
1000pF
–
+
A1
1/2 LT1632
C2
4.7µF
C5
4.7µF
C1
2.2µF
Figure 5. Tunable Q Notch Filter
PART NUMBER DESCRIPTON COMMENTS
LT1211/LT1212 Dual/Quad 14MHz, 7V/µs, Single Supply Precision Op Amps Input Common Mode Includes Ground, 275µV V
OS(MAX)
,
6µV/°C Max Drift, Max Supply Current 1.8mA per Op Amp
LT1213/LT1214 Dual/Quad 28MHz, 12V/µs, Single Supply Precision Op Amps Input Common Mode Includes Ground, 275µV V
OS(MAX)
,
6µV/°C Max Drift, Max Supply Current 3.5mA per Op Amp
LT1215/LT1216 Dual/Quad 23MHz, 50V/µs, Single Supply Precision Op Amps Input Common Mode Includes Ground, 450µV V
OS(MAX)
,
6µV/°C Max Drift, Max Supply Current 6.6mA per Op Amp
LT1498/LT1499 Dual/Quad 10MHz, 6V/µs Rail-to-Rail Input and Output High DC Accuracy, 475µV V
OS(MAX)
, 4µV/°C Max Drift,
C-Load
TM
Op Amps Max Supply Current 2.2mA per Amp
LT1630/LT1631 Dual/Quad 30MHz, 10V/µs Rail-to-Rail Input and Output Op Amps High DC Accuracy, 525µV V
OS(MAX)
, 70mA Output Current,
Max Supply Current 4.4mA per Amp
C-Load is a trademark of Linear Technology Corporation.
RELATED PARTS
f
RC
Rk
CpF
VV
R
RR
V
A
O
ODC
V
=
=
=
=
+
=
=
1
2
162
1000
5
11
11 10
25
2
π
.
.
()
Tunable Q Notch Filter
A single supply, tunable Q notch filter as shown in Figure
5 is built with LT1632 to maximize the output swing. The
filter has a gain of 2, and the notch frequency (f
O
) is set by
the values of R and C. The resistors R10 and R11 set up the
DC level at the output. The Q factor can be adjusted by
varying the value of R8. The higher value of R8 will
decrease Q as depicted in Figure 6, because the output
induces less of feedback to amplifier A2. The value of R7
should be equal or greater than R9 to prevent oscillation.
If R8 is a short and R9 is larger than R7, then the positive
feedback from the output will create phase inversion at the
output of amplifier A2, which will lead to oscillation.
FREQUENCY (kHz)
40
20
0
–20
–40
GAIN (V
OUT
/V
IN
)(dB)
13632/33 F06
0 20 40 60 140 160 180 20080 100 120
INCREASING R8
DECREASING R8
Figure 6. Frequency Response
