Datasheet

LT1568
14
1568f
Table 4. Resistor Values in Ohms, 4th Order Lowpass
Butterworth, Gain = 1
f
CUTOFF
(MHz) R11, R21 R31 R12, R22 R32
1 1.05k 1.58k 1.82k 887Ω
2 523Ω 787Ω 909Ω 432Ω
3 348Ω 523Ω 590Ω 294Ω
4 255Ω 383Ω 432Ω 215Ω
5 205Ω 309Ω 348Ω 174Ω
6 169Ω 255Ω 280Ω 143Ω
7 143Ω 221Ω 232Ω 124Ω
8 124Ω 196Ω 196Ω 107Ω
9 107Ω 174Ω 169Ω 97.6Ω
10 97.6Ω 158Ω 143Ω 88.7Ω
4th Order Lowpass Filter,
Dual Supply Operation
4th Order Lowpass Filter,
Single Supply Operation
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
+
INVA
SA
OUTA
OUTA
GNDA
NC
V
–
V
+
INVB
SB
OUTB
OUTB
GNDB
EN
V
–
0.1µF
V
IN
V
OUT
V
OUT
R11 R31
R22
R32 R12
R21
0.1µF
–5V
1568 TA05
5V
LT1568
BAT54S
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
+
INVA
SA
OUTA
OUTA
GNDA
NC
V
–
V
+
INVB
SB
OUTB
OUTB
GNDB
EN
V
–
0.1µF
V
IN
V
OUT
V
OUT
R11 R31
R22
R32 R12
R21
0.1µF
1568 TA06
V
+
LT1568
Amplitude Response
4th Order Lowpass Butterworth Lowpass, f
CUTOFF
= 1MHz
Transient Response
4th Order Lowpass Butterworth Lowpass, f
CUTOFF
= 1MHz
INPUT
500mV/DIV
OUTPUT
200mV/DIV
1µs/DIV
1568 TA14
FREQUENCY (MHz)
0.1
–60
GAIN (dB)
–48
–36
–24
–12
11020
1568 TA13
–72
–84
–96
–108
0
12
4th ORDER LOWPASS FILTER DESIG S
U