lt1568 Linear Technology Corporation, lt1568 Datasheet - Page 15

• Manufacturer Part Number: lt1568
• Description: Very Low Noise, High Frequency Active Rc, Filter Building Block
• Manufacturer: Linear Technology Corporation

4th ORDER LOWPASS FILTER DESIG S
Amplitude Response 4th Order Lowpass Chebyshev,
4th Order Lowpass Bessel, f
0.25dB Passband Ripple, f
–108
–108
–24
–36
–48
–60
–84
–96
–12
–72
–24
–36
–60
–84
–96
–12
–48
–72
12
12
0
0.1
0
0.1
Amplitude Response
FREQUENCY (MHz)
FREQUENCY (MHz)
1
1
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.
Table 5. Resistor Values in Ohms, 4th Order Lowpass
Chebyshev, 0.25dB Passband Ripple, Gain = 1
Table 6. Resistor Values in Ohms, 4th Order Lowpass Bessel,
Gain = 1
f
f
CUTOFF
CUTOFF
CUTOFF
CUTOFF
10
1568 TA13
10
1568 TA17
10
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
20
(MHz)
(MHz)
20
= 1MHz
= 1MHz
R11, R21
R11, R21
931
604
453
357
287
243
205
178
154
1.87k
715
357
237
174
137
115
U
2.05k
1.05k
681
511
402
332
287
249
221
196
562
374
280
221
187
1.15k
R31
R31
Transient Response 4th Order Lowpass Chebyshev,
500mV/DIV
200mV/DIV
500mV/DIV
200mV/DIV
OUTPUT
OUTPUT
R12, R22
R12, R22
INPUT
INPUT
4th Order Lowpass Bessel, f
2.21k
1.10k
698
499
383
309
255
215
182
158
432
280
205
162
130
1.91k
0.25dB Passband Ripple, f
Transient Response
86.6
76.8
66.5
61.9
634
324
205
154
121
100
324
365
243
187
147
124
R32
R32
1 s/DIV
1 s/DIV
CUTOFF
CUTOFF
1568 TA18
1568 TA16
= 1MHz
= 1MHz
LT1568
15
1568f