MP2357

– 0.5A, 24V, 1.4MHz STEP-DOWN CONVERTER IN A TSOT23-6

MP2357 Rev. 1.0

www.MonolithicPower.com

8

6/13/2013

MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.

© 2013 MPS. All Rights Reserved.

Figure2

―PCB Layout

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.3

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.

Table 2

—Suggested Surface Mount Inductors

Manufacturer

Part Number

Inductance(µH)

Max DCR(Ω)

Current

Rating (A)

Dimensions

Toko

A921CY-4R7M

4.7

0.027

1.66

6 x 6.3 x 3

Sumida

CDRH4D28C/LD

4.7

0.036

1.5

5.1 x 5.1 x 3

Wurth Electronics

744062005

4.7

0.060

2.2

5.9 x 6.2 x 3.3

TYPICAL APPLICATION CIRCUIT

Figure 4

—1.4MHz, 3.3V Output at 500mA Step-Down Converter