MP28313 – 2A, 16V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER

MP28313 Rev. 1.5

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10

9/27/2010

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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 Figure3

MP28313

SW

BST

C

L

BST

C

5V or 3.3V

OUT

External BST Diode

IN4148

+

Figure 3—Add Optional External Bootstrap

Diode to Enhance Efficiency

The recommended external BST diode is

IN4148, and the BST cap is 0.1~1µF.