MAX8649 Maxim Integrated Products, MAX8649 Datasheet - Page 29

• Manufacturer Part Number: MAX8649
• Description: 1.8A Step-Down Regulator
• Manufacturer: Maxim Integrated Products

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Calculate the inductor value (L
ing formula:
This sets the peak-to-peak inductor current ripple to 1/4
the maximum output current. The oscillator frequency,
f
Table 12. Recommended Inductors
OSC
MANUFACTURER
Hitachi Metals
Taiyo Yuden
, is 3.25MHz, and the duty cycle, D, is:
Coilcraft
TOKO
FDK
TDK
1.8A Step-Down Regulator with Differential
L
IDEAL
Applications Information
______________________________________________________________________________________
=
D
4
I
KSLI-2520AG
KLSI-2016AG
MIPSA2520D
OUT MAX
=
×
VLS3015T
Multilayer
Multilayer
CKP3216
Multilayer
DE2812C
LPS3008
LPS3010
SERIES
NR3015
V
V
IN
OUT
V
(
IN
×
D
IDEAL
Inductor Selection
Remote Sense in 2mm x 2mm WLP
)
×
×
(
f
1-
OSC
) using the follow-
D
)
INDUCTANCE
(µH)
0.75
0.56
0.56
0.80
0.68
1.0
1.5
2.2
1.0
1.5
0.5
1.3
1.6
2.0
1.0
1.5
2.2
1.0
1.5
1.0
2.2
1.2
1.5
2.0
1.0
1.5
2.2
1.0
1.5
1.8
2.2
Given L
is 0.25 x I
x I
the inductor exceeds the peak inductor current, and
the rated maximum DC inductor current exceeds the
maximum output current (
ues smaller than L
tor size; however, if much smaller values are used,
peak inductor current rises and a larger output capaci-
tance may be required to suppress output ripple.
Larger inductance values than L
obtain higher output current, but typically require a
physically larger inductor size. See Table 12 for rec-
ommended inductors.
DC RESISTANCE
OUT(MAX)
(Ω typ)
0.075
0.075
0.115
0.048
0.070
0.032
0.044
0.050
0.067
0.072
0.092
0.125
0.134
0.070
0.080
0.085
0.120
0.150
0.09
0.09
0.13
0.11
0.10
0.09
0.06
0.11
0.13
0.14
0.03
0.04
IDEAL
OUT(MAX)
. Make sure that the saturation current of
, the peak-to-peak inductor ripple current
CURRENT RATING
IDEAL
. The peak inductor current is 1.125
can be used to reduce induc-
(mA)
1800
1800
1400
1500
1500
1100
2000
2000
2000
2000
1100
1000
2100
1800
2000
1400
2300
1800
1500
1400
1800
1600
1400
1150
2300
1800
1600
1300
1200
900
OUT(MAX)
IDEAL
). Inductance val-
L x W x H (mm)
can be used to
DIMENSIONS
2.5 x 2.0 x 1.0
2.0 x 1.6 x 1.0
2.5 x 2.0 x 0.5
3.2 x 1.6 x 0.9
3.0 x 3.0 x 1.5
3.0 x 3.0 x 1.5
3.2 x 3.0 x 1.2
3.0 x 3.0 x 0.8
3.0 x 3.0 x 1.0
29