Microchip Technology ADM00423 Hoja De Datos
MCP16321/2
DS22285A-page 20
© 2011 Microchip Technology Inc.
5.0.6
INDUCTOR SELECTION
The MCP16321/2 is designed to be used with small
surface mount inductors. Several specifications should
be considered prior to selecting an inductor. To
optimize system performance, low ESR inductors
should be used.
surface mount inductors. Several specifications should
be considered prior to selecting an inductor. To
optimize system performance, low ESR inductors
should be used.
EQUATION 5-3:
INDUCTOR CURRENT
RIPPLE
RIPPLE
EXAMPLE 5-3:
MCP16321 PEAK
INDUCTOR CURRENT – 1A
INDUCTOR CURRENT – 1A
An inductor saturation rating minimum of 1.255A is
recommended. A trade-off between size, cost and
efficiency is made to achieve the desired results.
recommended. A trade-off between size, cost and
efficiency is made to achieve the desired results.
EXAMPLE 5-4:
MCP16322 PEAK
INDUCTOR CURRENT – 2A
INDUCTOR CURRENT – 2A
An inductor saturation rating minimum of 2.255A is
recommended. A trade-off between size, cost and
efficiency is made to achieve the desired results.
recommended. A trade-off between size, cost and
efficiency is made to achieve the desired results.
C
OUT
33 µF
None
V
IN
= 12V
V
OUT
= 3.3V
I
OUT
= 1A
L = 4.7 µH
Inductor ripple current = 509 mA
Inductor peak current = 1.255A
Inductor peak current = 1.255A
V
IN
= 12V
V
OUT
= 3.3V
I
OUT
= 2A
L = 4.7 µH
Inductor ripple current = 509 mA
Inductor peak current = 2.255A
Inductor peak current = 2.255A
TABLE 5-1:
CAPACITOR VALUE RANGE
Parameter
Min
Max
Δ
I
L
V
L
L
------
t
ON
×
=
I
LPK
Δ
I
L
2
---------
I
OUT
+
=
I
LPK
Δ
I
L
2
---------
I
OUT
+
=
TABLE 5-2:
MCP16321 RECOMMENDED
INDUCTORS
INDUCTORS
Part
Number
Value
(µH)
DCR
(
Ω)
I
SAT
(A)
Size
WxLxH
(mm)
Coilcraft
®
1008PS
4.7
0.35
1.7
3.81x3.78x2.74
LPS4012
4.7
0.175
1.8
4.1x4.1x1.2
LPS4018
4.7
0.125
1.9
4.1x4.1x1.8
LPS5015
4.7
0.15
1.8
5x5x1.5
MSS5121
4.7
0.095
1.66
5.1x5.1x2.2
LPS5030
4.7
0.083
2
5x5x3
MSS6122
4.7
0.065
1.82
6.1x6.1x2.2
MOS6020
4.7
0.05
1.94
6.8x6x2.4
Wurth Elektronik
®
744042
4.7
0.07
1.65
4.8x4.8x1.8
744068
4.7
0.072
1.55
8x8x1.1
7448944
4.7
0.0545
4.2
8x8x3.8
EPCOS
®
LTF5022T
4.7
0.073
2
5.2x5x2.2
VLC5020T
4.7
0.097
2
5x5x2
VLC6020T
4.7
0.079
1.8
6x6x2
VLCF5020T
4.7
0.122
1.7
5x5x2
VLF5014ST
4.7
0.12
1.7
4.8x4.6x1.4
TABLE 5-3:
MCP16322 RECOMMENDED
INDUCTORS
INDUCTORS
Part Number
Value
(µH)
DCR
(
Ω)
I
SAT
(A)
Size
WxLxH
(mm)
Coilcraft
®
MSS6132-472
4.7
0.056
2.84
6.1x6.1x3.2
LPS6225-472
4.7
0.065
3.2
6.2x6.2x2.5
MSS7341-502
4.7
0.024
3.16
7.3x7.3x4.1
DO1813H-472
4.7
0.054
2.6
8.89x6.1x5.0
Wurth Elektronik
®
7447785004
4.7
0.06
2.5
5.9x6.2x3.3
7447786004
4.7
0.057
2.8
5.9x6.2x5.1
7447789004
4.7
0.033
3.9
7.3x3.2x1.5
EPCOS
®
B82464G2
4.7
0.033
3.1
10.4x10.4x3.0
B82464A2
4.7
0.03
4.5
10.4x10.4x3.0