LC Filter Circuit Design
Designing low- and high-pass filters using off-the shelf components
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.
The S3LP and S3HP modules incorporate the components of this design into 1812-size
surface mount packages.
Low pass filter
IN
L1
L2
OUT
IN
High pass filter
C1
C2
OUT
C1
L1
3-Pole Low Pass Filters
–3 dB
cutoff
(MHz)
3
6
10
13
15
30
45
60
70
95
100
110
150
200
230
300
350
400
450
500
700
800
900
1000
1200
1500
1600
1800
2000
2600
3000
L1 part number
0805HT-R79TGLB
0805HT-R79TGLB
0805HT-R63TGLB
0805HT-R63TGLB
0805HT-R50TGLB
0805HT-R18TGLB
0805HT-R18TGLB
0805HT-R12TGLB
0805HT-R10TGLB
0805HT-72NTGLB
0805HT-68NTGLB
0805HT-68NTGLB
0805HT-68NTGLB
0805HT-33NTGLB
0805HT-33NTGLB
0805HT-33NTGLB
0805HT-18NTGLB
0805HT-17NTGLB
0805HT-18NTGLB
0805HT-18NTGLB
0805HT-8N2TGLB
0805HT-8N2TGLB
0805HT-4N7TGLB
0805HT-3N9TGLB
0805HT-3N9TGLB
0805HT-3N9TGLB
0805HT-2N2TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
L2 part number
0805HT-R79TGLB
0805HT-R79TGLB
0805HT-R63TGLB
0805HT-R63TGLB
0805HT-R50TGLB
0805HT-R18TGLB
0805HT-R18TGLB
0805HT-R12TGLB
0805HT-R10TGLB
0805HT-72NTGLB
0805HT-68NTGLB
0805HT-68NTGLB
0805HT-68NTGLB
0805HT-33NTGLB
0805HT-33NTGLB
0805HT-33NTGLB
0805HT-18NTGLB
0805HT-17NTGLB
0805HT-18NTGLB
0805HT-18NTGLB
0805HT-8N2TGLB
0805HT-8N2TGLB
0805HT-4N7TGLB
0805HT-3N9TGLB
0805HT-3N9TGLB
0805HT-3N9TGLB
0805HT-2N2TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
0805HT-1N8TJLB
L1
(nH)
790 ±2%
790 ±2%
630 ±2%
630 ±2%
500 ±2%
180 ±2%
180 ±2%
120 ±2%
100 ±2%
72 ±2%
68 ±2%
68 ±2%
68 ±2%
33 ±2%
33 ±2%
33 ±2%
18 ±2%
17 ±2%
18 ±2%
18 ±2%
8.2 ±2%
8.2 ±2%
4.7 ±2%
3.9 ±2%
3.9 ±2%
3.9 ±2%
2.2 ±5%
1.8 ±5%
1.8 ±5%
1.8 ±5%
1.8 ±5%
L2
C1 ±2%
(nH)
(pF)
790 ±2%
2400
790 ±2%
1200
630 ±2%
680
630 ±2%
470
500 ±2%
390
180 ±2%
220
180 ±2%
120
120 ±2%
100
100 ±2%
91
72 ±2%
62
68 ±2%
56
68 ±2%
56
68 ±2%
33
33 ±2%
30
33 ±2%
24
33 ±2%
15
18 ±2%
15
17 ±2%
12
18 ±2%
10
18 ±2%
9.1
8.2 ±2%
6.8
8.2 ±2%
5.6
4.7 ±2%
5.6
3.9 ±2%
4.7
3.9 ±2%
3.6
3.9 ±2%
2.7
1.8 ±5%
2.7
1.8 ±5%
2.0
1.8 ±5%
1.5
1.8 ±5%
1.0
1.8 ±5%
0.5
Coilcraft
low pass filter
part number
S3LP305L
S3LP605L
S3LP106L
S3LP136L
S3LP156L
S3LP306L
S3LP456L
S3LP606L
S3LP706L
S3LP956L
S3LP107L
S3LP117L
S3LP157L
S3LP207L
S3LP237L
S3LP307L
S3LP357L
S3LP407L
S3LP457L
S3LP507L
S3LP707L
S3LP807L
S3LP907L
S3LP108L
S3LP128L
S3LP158L
S3LP168L
S3LP188L
S3LP218L
S3LP268L
S3LP308L
3-Pole High Pass Filters
–3 dB
cutoff
(MHz)
15
30
60
100
150
300
500
700
800
900
L1 part number
0805HT-R22TGLB
0805HT-R18TGLB
0805HT-68NTGLB
0805HT-39NTGLB
0805HT-27NTGLB
0805HT-15NTGLB
0805HT-6N8TGLB
0805HT-3N9TGLB
0805HT-3N9TGLB
0805HT-3N9TGLB
L1
±2%
(nH)
220
180
68
39
27
15
6.8
3.9
3.9
3.9
C1
±2%
(pF)
330
68
56
39
20
6.8
5.6
4.5
3.0
2.2
C2
±2%
(pF)
390
68
56
39
20
6.8
5.6
4.5
3.0
2.2
Coilcraft
high pass filter
part number
S3HP156L
S3HP306L
S3HP606L
S3HP107L
S3HP157L
S3HP307L
S3HP507L
S3HP707L
S3HP807L
S3HP907L
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.
Document R124-1
Revised 04/15/14
LC Filter Circuit Design
Designing low- and high-pass filters using off-the shelf components
These low-pass filter circuits serve a wide variety of filtering requirements. The design fea-
tures 7th order elliptic alignment, 50 Ohm characteristic impedance and low insertion loss.
The P7LP modules incorporate the components of this design.
IN
C1
C2
L1
C3
C4
L2
C5
C6
L3
C7
OUT
7-Pole Low Pass Filters
–3 dB
cutoff
(MHz)
0.30
0.50
0.60
0.62
0.80
0.90
1.0
1.3
1.5
2.0
3.0
4.2
4.5
5.0
6.0
9.0
10
15
17
20
30
45
60
70
88
90
100
150
200
220
250
300
400
500
L1 part number
1812LS-333XJLB
1812LS-183XJLB
1812LS-183XJLB
1008LS-153XJLB
1812LS-123XJLB
1812LS-123XJLB
1812CS-103XJLB
1008CS-472XJLB
1008LS-682XJLB
1008LS-332XJLB
1008LS-332XJLB
1008CS-182XJLB
1008CS-152XJLB
1008CS-182XJLB
1008CS-222XJLB
1008CS-102XJLB
1008CS-102XJLB
1008CS-681XJLB
1008CS-911XJLB
1008CS-561XJLB
1008CS-331XJLB
1008CS-221XJLB
1008CS-151XJLB
1008CS-151XJLB
1008CS-121XJLB
1008CS-121XJLB
1008CS-101XJLB
1008CS-620XJLB
1008CS-470XJLB
1008CS-330XJLB
1008CS-150XJLB
1008CS-270XJLB
1008CS-180XJLB
1008CS-100XJLB
L2 part number
1812LS-333XJLB
1812LS-223XJLB
1812LS-183XJLB
1008LS-153XJLB
1812LS-123XJLB
1812LS-123XJLB
1812CS-103XJLB
1008CS-472XJLB
1008LS-682XJLB
1008LS-332XJLB
1008LS-332XJLB
1008CS-182XJLB
1008CS-621XJLB
1008CS-222XJLB
1008CS-272XJLB
1008CS-102XJLB
1008CS-102XJLB
1008CS-681XJLB
1008CS-911XJLB
1008CS-561XJLB
1008CS-221XJLB
1008CS-181XJLB
1008CS-151XJLB
1008CS-151XJLB
1008CS-121XJLB
1008CS-121XJLB
1008CS-101XJLB
1008CS-680XJLB
1008CS-470XJLB
1008CS-330XJLB
1008CS-120XJLB
1008CS-180XJLB
1008CS-120XJLB
0805CS-060XJLB
L3 part number
1812LS-273XJLB
1812LS-183XJLB
1812LS-153XJLB
1008LS-153XJLB
1812LS-153XJLB
1812LS-103XJLB
1812CS-822XJLB
1008CS-472XJLB
1008LS-562XJLB
1008LS-332XJLB
1008LS-272XJLB
1008CS-182XJLB
1008CS-821XJLB
1008CS-182XJLB
1008CS-222XJLB
1008CS-102XJLB
1008CS-102XJLB
1008CS-561XJLB
1008CS-911XJLB
1008CS-471XJLB
1008CS-221XJLB
1008CS-181XJLB
1008CS-121XJLB
1008LS-121XJLB
1008CS-121XJLB
1008LS-101XJLB
1008CS-850XJLB
1008CS-500XJLB
1008CS-390XJLB
1008CS-330XJLB
1008CS-270XJLB
1008CS-180XJLB
1008CS-120XJLB
0805CS-060XJLB
L1
±5%
(nH)
33000
18000
18000
15000
12000
12000
10000
4700
6800
3300
3300
1800
1500
1800
2200
1000
1000
680
910
560
330
220
150
150
120
120
100
62
47
33
15
27
18
10
L2
±5%
(nH)
33000
22000
18000
15000
12000
12000
10000
4700
6800
3300
3300
1800
620
2200
2700
1000
1000
680
910
560
220
180
150
150
120
120
100
68
47
33
12
18
12
6.8
L3
±5%
(nH)
27000
18000
15000
15000
15000
10000
8200
4700
5600
3300
2700
1800
820
1800
2200
1000
1000
560
910
470
220
180
120
120
120
100
85
50
39
33
27
18
12
6.8
C1
C2
±5%
±5%
(pF)
(pF)
6800
510
3300
270
3300
270
3300
240
2200
150
2200
200
1800
160
1500
110
1200
100
1200
100
620
50
620
50
600
210
390
30
240
200
220
3000
200
16
130
10
120
6
100
10
100
15
47
8.2
30
2.7
27
2.2
20
1.6
20
1.6
20
1.8
100
1
8.2
1
8.2
1
1.2
10
8.2
1.5
6.5
1
4.7
1
C3
±5%
(pF)
15000
6800
6800
6800
5600
5600
4700
1800
3300
3300
1500
1200
710
910
620
560
510
330
180
270
140
68
68
600
50
50
47
30
200
200
8.2
10
9.1
5.6
C4
±5%
(pF)
3300
1800
1800
1000
750
820
680
620
510
510
300
300
1200
130
90
120
100
75
27
39
75
47
24
1000
10
10
7.5
4.7
3
3
17
7
5.1
6.2
C5
±5%
(pF)
15000
6800
6800
6800
5600
5600
4700
1800
3300
3300
1500
1200
560
910
560
560
510
300
180
270
120
56
600
600
47
47
47
30
200
200
10
9.5
8.2
4.3
C6
±5%
(pF)
1500
910
910
910
560
6800
560
1800
360
360
180
180
800
110
75
100
600
36
27
3000
56
3000
9.1
7.5
6.2
6.2
6
3.3
2.2
2.2
2.7
5.1
3.9
4.3
C7
Coilcraft
±5%
low pass filter
(pF)
part number
5600
P7LP-304L
2200
P7LP-504L
2200
P7LP-604L
2200
P7LP-624L
1800
P7LP-804L
1800
P7LP-904L
1500
P7LP-105L
1500
P7LP-135L
1000
P7LP-155L
1000
P7LP-205L
510
P7LP-305L
50
P7LP-425L
250
P7LP-455L
300
P7LP-505L
220
P7LP-605L
200
P7LP-905L
160
P7LP-106L
100
P7LP-156L
120
P7LP-176L
100
P7LP-206L
70
P7LP-306L
3000
P7LP-456L
27
P7LP-606L
200
P7LP-706L
18
P7LP-886L
18
P7LP-906L
16
P7LP-107L
10
P7LP-157L
6.8
P7LP-207L
6.8
P7LP-227L
6
P7LP-257L
5.6
P7LP-307L
4.7
P7LP-407L
3
P7LP-507L
Notes:
All values are for reference only. Layout and substrate affect final performance.
7th order elliptic filter (refer to schematics). Ref. 50 Ohms.
Use 0805 NPO/COG capacitors. Higher cut-off frequencies may require tighter tolerance.
Improved performance may be achieved by using other (typically larger) inductors. Use the
RF Inductor Finder
tool to find alternatives.
Document R124-2
Revised 04/15/14
