LC Filter Circuit Design
Designing low- and high-pass filters using off-the shelf components
Low pass filter
High pass filter
These low and high pass filter circuits serve a wide variety of filtering requirements. The
design features 3rd order Butterworth alignment, 50 Ohm characteristic impedance and
low insertion loss.
C1
C2
L1
L2
IN
OUT
IN
OUT
The S3LP and S3HP modules incorporate the components of this design into 1812-size
surface mount packages.
C1
L1
3-Pole Low Pass Filters
3-Pole High Pass Filters
–3 dB
cutoff
Coilcraft
–3 dB
cutoff
(MHz)
L1
2ꢀ
C1
C2
Coilcraft
L1
(nH)
L2
(nH)
C1 2ꢀ low pass filter
2ꢀ
2ꢀ high pass filter
(MHz)
L1 part number
L2 part number
(pF)
part number
L1 part number
(nH)
(pF)
(pF)
part number
3
6
10
13
15
0805HT-R79TGLB 0805HT-R79TGLB
0805HT-R79TGLB 0805HT-R79TGLB
0805HT-R63TGLB 0805HT-R63TGLB
0805HT-R63TGLB 0805HT-R63TGLB
0805HT-R50TGLB 0805HT-R50TGLB
790 2ꢀ
790 2ꢀ
630 2ꢀ
630 2ꢀ
500 2ꢀ
790 2ꢀ
790 2ꢀ
630 2ꢀ
630 2ꢀ
500 2ꢀ
2400
1200
680
470
390
S3LP305L
S3LP605L
S3LP106L
S3LP136L
S3LP156L
15
30
60
100
150
0805HT-R22TGLB
0805HT-R18TGLB
0805HT-68NTGLB
0805HT-39NTGLB
0805HT-27NTGLB
220
180
68
39
27
330
390
68
56
39
20
S3HP156L
S3HP306L
S3HP606L
S3HP107L
S3HP157L
68
56
39
20
30
45
60
70
95
0805HT-R18TGLB 0805HT-R18TGLB
0805HT-R18TGLB 0805HT-R18TGLB
0805HT-R12TGLB 0805HT-R12TGLB
0805HT-R10TGLB 0805HT-R10TGLB
0805HT-72NTGLB 0805HT-72NTGLB
180 2ꢀ
180 2ꢀ
120 2ꢀ
100 2ꢀ
72 2ꢀ
180 2ꢀ
180 2ꢀ
120 2ꢀ
100 2ꢀ
72 2ꢀ
220
120
100
91
S3LP306L
S3LP456L
S3LP606L
S3LP706L
S3LP956L
300
500
700
800
900
0805HT-15NTGLB
0805HT-6N8TGLB
0805HT-3N9TGLB
0805HT-3N9TGLB
0805HT-3N9TGLB
15
6.8
6.8
S3HP307L
S3HP507L
S3HP707L
S3HP807L
S3HP907L
6.8
3.9
3.9
3.9
5.6
4.5
3.0
2.2
5.6
4.5
3.0
2.2
62
100
110
150
200
230
0805HT-68NTGLB 0805HT-68NTGLB
0805HT-68NTGLB 0805HT-68NTGLB
0805HT-68NTGLB 0805HT-68NTGLB
0805HT-33NTGLB 0805HT-33NTGLB
0805HT-33NTGLB 0805HT-33NTGLB
68 2ꢀ
68 2ꢀ
68 2ꢀ
33 2ꢀ
33 2ꢀ
68 2ꢀ
68 2ꢀ
68 2ꢀ
33 2ꢀ
33 2ꢀ
56
56
33
30
24
S3LP107L
S3LP117L
S3LP157L
S3LP207L
S3LP237L
Notes:
All values are for reference only. Layout and substrate affect final performance.
3rd order Butterworth filter (refer to schematics). Ref. 50 Ohms.
Improved performance may be achieved by using other (typically larger) inductors.
Use the RF Inductor Finder tool to find alternatives.
300
350
400
450
500
0805HT-33NTGLB 0805HT-33NTGLB
0805HT-18NTGLB 0805HT-18NTGLB
0805HT-17NTGLB 0805HT-17NTGLB
0805HT-18NTGLB 0805HT-18NTGLB
0805HT-18NTGLB 0805HT-18NTGLB
33 2ꢀ
18 2ꢀ
17 2ꢀ
18 2ꢀ
18 2ꢀ
33 2ꢀ
18 2ꢀ
17 2ꢀ
18 2ꢀ
18 2ꢀ
15
15
12
10
S3LP307L
S3LP357L
S3LP407L
S3LP457L
S3LP507L
9.1
700
800
900
1000
1200
0805HT-8N2TGLB 0805HT-8N2TGLB
0805HT-8N2TGLB 0805HT-8N2TGLB
0805HT-4N7TGLB 0805HT-4N7TGLB
0805HT-3N9TGLB 0805HT-3N9TGLB
0805HT-3N9TGLB 0805HT-3N9TGLB
8.2 2ꢀ
8.2 2ꢀ
4.7 2ꢀ
3.9 2ꢀ
3.9 2ꢀ
8.2 2ꢀ
8.2 2ꢀ
4.7 2ꢀ
3.9 2ꢀ
3.9 2ꢀ
6.8
5.6
5.6
4.7
3.6
S3LP707L
S3LP807L
S3LP907L
S3LP108L
S3LP128L
1500
1600
1800
2000
2600
0805HT-3N9TGLB 0805HT-3N9TGLB
3.9 2ꢀ
2.2 5ꢀ
1.8 5ꢀ
1.8 5ꢀ
1.8 5ꢀ
3.9 2ꢀ
1.8 5ꢀ
1.8 5ꢀ
1.8 5ꢀ
1.8 5ꢀ
2.7
2.7
2.0
1.5
1.0
S3LP158L
S3LP168L
S3LP188L
S3LP218L
S3LP268L
0805HT-2N2TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
0805HT-2N2TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
3000
0805HT-1N8TJLB
0805HT-1N8TJLB
1.8 5ꢀ
1.8 5ꢀ
0.5
S3LP308L
Document R124-1 Revised 04/15/14