MP1584 – 3A, 1.5MHz, 28V STEP-DOWN CONVERTER
MPS CONFIDENTIAL AND PROPRIETARY INFORMATION – INTERNAL USE ONLY
Table 1—Inductor Selection Guide
Dimensions
Part Number
Wurth Electronics
7447789003
Inductance (µH) Max DCR (Ω) Current Rating (A)
L x W x H (mm3)
3.3
10
15
22
0.024
0.035
0.025
0.031
3.42
3.6
7.3x7.3x3.2
10x10x3.8
12x12x6
744066100
744771115
3.75
3.37
744771122
12x12x6
TDK
RLF7030T-3R3
RLF7030T-4R7
SLF10145T-100
SLF12565T-220M3R5
Toko
3.3
4.7
10
0.02
4.1
3.4
3
7.3x6.8x3.2
7.3x6.8x3.2
0.031
0.0364
0.0316
10.1x10.1x4.5
12.5x12.5x6.5
22
3.5
FDV0630-3R3M
FDV0630-4R7M
919AS-100M
919AS-160M
919AS-220M
3.3
4.7
10
16
22
0.031
0.049
4.3
3.3
4.3
3.3
3
7.7x7x3
7.7x7x3
0.0265
0.0492
0.0776
10.3x10.3x4.5
10.3x10.3x4.5
10.3x10.3x4.5
Output Rectifier Diode
Input Capacitor
The output rectifier diode supplies the current to
the inductor when the high-side switch is off. To
reduce losses due to the diode forward voltage
and recovery times, use a Schottky diode.
The input current to the step-down converter is
discontinuous, therefore a capacitor is required to
supply the AC current to the step-down converter
while maintaining the DC input voltage. Use low
ESR capacitors for the best performance. Ceramic
capacitors are preferred, but tantalum or low-ESR
electrolytic capacitors may also suffice.
Choose a diode whose maximum reverse
voltage rating is greater than the maximum
input voltage, and whose current rating is
greater than the maximum load current. Table 2
For simplification, choose the input capacitor
with RMS current rating greater than half of the
maximum load current.
lists
example
Schottky
diodes
and
manufacturers.
Table 2—Diode Selection Guide
Voltage/
Diodes
Current
Rating
Manufacturer
B340A-13-F
CMSH3-40MA
40V, 3A
40V, 3A
Diodes Inc.
Central Semi
MP1584 Rev. 1.0
4/7/2009
www.MonolithicPower.com
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
© 2009 MPS. All Rights Reserved.
11
MPS [ MONOLITHIC POWER SYSTEMS ]
