Datasheet

13
LTC1562
1562fa
TYPICAL APPLICATIONS
U
(Basic)
Quad 3rd Order Butterworth Lowpass Filter, Gain = –1
Quad 3rd Order
Butterworth f
–3dB
f
–3dB
f
–3dB
f
–3dB
f
–3dB
f
–3dB
f
–3dB
Lowpass Filters 20kHz 40kHz 60kHz 80kHz 100kHz 120kHz 140kHz
C
IN
220pF 1000pF 1000pF 1000pF 1000pF 1000pF 1000pF
R
INA
44.2k 4.32k 3.16k 2.43k 1.96k 1.87k 1.69k
R
INB
205k 57.6k 24.3k 13.0k 8.06k 5.11k 3.4k
R
Q
249k 61.9k 27.4k 15.4k 10.0k 6.98k 5.11k
R2 249k 61.9k 27.4k 15.4k 10.0k 6.98k 5.11k
All four sections have identical R
INA
, R
INB
and C
IN
values. All resistor values are ±1%
FREQUENCY (Hz)
10k
GAIN (dB)
10
0
–10
–20
–30
–40
–50
–60
100k 1M
1562 TA05b
f
–3dB
= 100kHz
1
2
3
5
6
8
9
10
20
19
18
16
15
13
12
11
INV B
V1 B
V2 B
V
+
SHDN
V2 A
V1 A
INV A
INV C
V1 C
V2 C
V
–
AGND
V2 D
V1 D
INV D
LTC1562
R
IN1B
R
IN1A
R
IN3A
V
IN1
V
IN3
C
IN1
V
IN2
1562 TA05a
V
OUT2
V
OUT3
V
OUT4
V
OUT1
R
IN3B
–5V
5V
R
Q1
R21
R23
0.1µF
0.1µF
R
Q3
R24
R
Q4
R
Q2
R22
C
IN2
C
IN3
R
IN2B
R
IN2A
V
IN4
C
IN4
R
IN4B
R
IN4A
SCHEMATIC INCLUDES PIN NUMBERS FOR 20-PIN PACKAGE.
PINS 4, 7, 14, 17 (NOT SHOWN) ALSO CONNECT TO V
–
Amplitude Response