Rainbow Electronics MAX8982X - Manual (Page 69)

Power-Management ICs for
ICERA E400/E450 Platform
MAX8982A/MAX8982X
69
Applications Information
Inductor Selection
The step-down converters operate with inductors of 1FH
to 4.7FH. Low inductance values are physically smaller,
but require faster switching, which results in some effi-
ciency loss. The inductor’s DC current rating only needs
to match the maximum load current of the application
plus 100mA because the step-down converters feature
zero current overshoot during startup and load transients.
For optimum voltage positioning load transients, choose
an inductor with DC series resistance in the 30m
W
to 100m W range. For higher efficiency at heavy load
(above 200mA) or minimal load regulation (but some
transient overshoot), the resistance should be kept
below 100m
W. For light load applications up to 200mA,
a higher resistance is acceptable with very little impact
on performance.
Recommended inductors are listed in Table 60.
Table 60. Recommended Inductors
MANUFACTURER SERIES
INDUCTANCE
(FH)
DC RESISTANCE
(I typ)
CURRENT
RATING (mA)
D T = +40NC RISE
DIMENSIONS
L x W x H (mm)
TOKO
MDT2520-CR
1.0 0.06 1550
2.5 x 2.0 x 1.0
1.5 0.08 1400
2.2 0.09 1350
3.3 0.10 1300
DE2810C
Flat Wire
1.5 0.06 2000
3.0 x 2.8 x 1.0
2.2 0.085 1600
3.3 0.130 1300
4.7 0.180 1100
DE2812C
Flat Wire
1.5 0.050 2600
3.0 x 2.8 x 1.2
2.0 0.067 2300
3.3 0.100 1700
4.7 0.130 1500
DEM3518C 2.2 0.040 2550 3.9 x 3.7 x 1.8
DEM2818C* 2.2 0.039 2200 3.0 x 3.0 x 1.8
Hitachi-Metals
KSLI-252010AG
1 0.050 2600
2.5 x 2.0 x 1.0
2.2 0.100 1800
3.3 0.100 1800
4.7 0.115 1700
KSLI-201610AG
1 0.090 1900
2.0 x 1.6 x 1.0
2.2 0.140 1500
3.3 0.180 1300
4.7 0.200 1300
KSLI-201210AG
1 0.120 1500
2.0 x 1.2 x 1.0
2.2 0.190 1300
3.3 0.230 1200
4.7 0.270 1100
KSLI-252012AG-2R2** 2.2 0.1 1900 2.5 x 2.0 x 1.2