MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER

MP1583 Rev. 3.1

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10

6/20/2011

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D1

C4

R3

C5

R4

L1

SGND

PGND

C6

C2

C3

C1

Top Layer

Bottom Layer

Figure 3―PCB Layout (Double Layer)

External Bootstrap Diode

An external bootstrap diode may enhance the

efficiency of the regulator, the applicable

conditions of external BST diode are:

Duty cycle is high: D=

IN

OUT

V

V

>65%

In these cases, an external BST diode is

recommended from the output of the voltage

regulator to BST pin, as shown in Fig.4

MP1583

SW

BST

C

L

BST

C

5V or 3.3V

OUT

External BST Diode

IN4148

+

Figure 4—Add Optional External Bootstrap

Diode to Enhance Efficiency

The recommended external BST diode is

IN4148, and the BST cap is 0.1~1µF.