LT1568 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LT1568' PDF : 16 Pages View PDF
U
4th ORDER LOWPASS FILTER DESIG S
Table 5. Resistor Values in Ohms, 4th Order Lowpass
Chebyshev, ±0.25dB Passband Ripple, Gain = 1
fCUTOFF (MHz)
1
R11, R21
1.87k
R31
2.05k
R12, R22
2.21k
2
931Ω
1.05k
1.10k
3
604Ω
681Ω
698Ω
4
453Ω
511Ω
499Ω
5
357Ω
402Ω
383Ω
6
287Ω
332Ω
309Ω
7
243Ω
287Ω
255Ω
8
205Ω
249Ω
215Ω
9
178Ω
221Ω
182Ω
10
154Ω
196Ω
158Ω
R32
634Ω
324Ω
205Ω
154Ω
121Ω
100Ω
86.6Ω
76.8Ω
66.5Ω
61.9Ω
LT1568
Amplitude Response 4th Order Lowpass Chebyshev,
±0.25dB Passband Ripple, fCUTOFF = 1MHz
12
0
–12
–24
–36
–48
–60
–72
–84
–96
–108
0.1
1
FREQUENCY (MHz)
10 20
1568 TA13
Transient Response 4th Order Lowpass Chebyshev,
±0.25dB Passband Ripple, fCUTOFF = 1MHz
INPUT
500mV/DIV
OUTPUT
200mV/DIV
1µs/DIV
1568 TA16
Table 6. Resistor Values in Ohms, 4th Order Lowpass Bessel,
Gain = 1
fCUTOFF (MHz)
1
R11, R21
715Ω
R31
1.15k
R12, R22
1.91k
R32
324Ω
2
357Ω
562Ω
432Ω
365Ω
3
237Ω
374Ω
280Ω
243Ω
4
174Ω
280Ω
205Ω
187Ω
5
137Ω
221Ω
162Ω
147Ω
6
115Ω
187Ω
130Ω
124Ω
Amplitude Response
4th Order Lowpass Bessel, fCUTOFF = 1MHz
12
0
–12
–24
–36
–48
–60
–72
–84
–96
–108
0.1
1
FREQUENCY (MHz)
10 20
1568 TA17
Transient Response
4th Order Lowpass Bessel, fCUTOFF = 1MHz
INPUT
500mV/DIV
OUTPUT
200mV/DIV
1µs/DIV
1568 TA18
1568f
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
Share Link: 
