MP24971DS-LF-Z Datasheet, PDF (12/14 Pages) MPS Industries, Inc. – 1.5A, 50V, 100kHz, 5V Fixed Output Step- Down Converter with Programmable Current Limit and Output Line-Drop Compensation

MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER
PC Board Layout
The high frequency paths for VIN, SW and
GND should be routed very close to the device
with short, direct, and wide traces. Place the
input capacitor as close as possible to the IN
and GND pins. Place the external feedback
resistors next to the FB pin. Keep the switching
node SW short and away from the feedback
network.
External Bootstrap Diode
An external bootstrap diode helps improve the
efficiency of the regulator when the system has
a 5V fixed input or the power supply generates
a 5V output. The bootstrap diode can be low-
cost, such as an IN4148 or a BAT54.
Add a diode for high duty-cycle operation (when
V_{OUT >65%).}
V_IN
D₁
NS
Vcc
R1
C₄
0O
0.1µF
C2
BST
SW
2.2µF
V_IN
VIN
C1
100µ F
C3
0.1µF
VOC
GND
MP24971
5V
BS
MP24971
SW
10nF
Figure 5—External Bootstrap Diode
Design Example
Below is a sample design that follows the
application guidelines for the specifications
below:
Parameter
Input Voltage
Output Voltage
Output Current Limit
Output OVP
Symbol
V_IN
V_OUT
I_OUT-L
V_OVP
Value
8 - 50
5
1.5
6
Units
V
V
A
V
Figure 6 shows the detailed application
schematic. The Typical Performance
Characteristics performance and circuit
waveforms are all based on this design. For
additional implentations, consult the Evaluation
Board Data Sheets.
L1
33µH
C₉
C₈
C7
100µF 22µF 0.1µF
R₆
100mO
D2
+
B 360A
R₂
402kO
R₅
100O
R₇
165O
C10
NS
C₁₁
0.1µF
VOUT
GND
GND
VOS
ISP
C5
10nF
R₃
1kO
ISN
C₆
10nF
R₄
1kO
R8
0O
Figure 6—Detailed Sample Application Schematic
MP24971 Rev. 1.01
www.MonolithicPower.com
12
1/6/2012
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