MP8757–18V, HIGH CURRENT SYNCHRONOUS BUCK CONVERTER

MP8757 Rev. 1.0

www.MonolithicPower.com

19

5/1/2018

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9

SW

17

16

14

EN

PGND

VCC

13

PG

VIN

12

15

GND

19

VIN

20

PGND

21

PGND

1

2

3

5

6

7

8

4

To

AGND

11

10

VOUT

AGND KELVIN

CONNECT TO PGND

AT VCC CAP

VIN

VOUT

DO NOT CONNECT

TO PGND HERE

FB

At least two layers should be applied for Vin

and PGND and place >20 vias close to the

part for a better thermal performance

18

PGND

AGND

AGND

--Top Layer

--Via

--Bottom Layer

--Inner PGND Layer

--Inner Layer2

--Via For AGND

PGND

BST

NC

NC

NC

NC

Figure 13

—Recommend Layout

Recommend Design Example

Some design examples are provided below when

the ceramic capacitors are applied:

Table 2

—Design Example

(V)

Cout

(F)

L

(

μH)

R4

(

Ω)

C4

(F)

R1

(k

Ω)

R2

(k

Ω)

1.05

22

μx3

1.2

NS

220p

59

82

1.2

22

μx3

1.2

NS

220p

100

102

1.35

22

μx3

1.2

NS

220p

100

82

3.3

22ux4

2

1M

220p

88.7

18

5

22ux4

2

1M

220p

150

18

The detailed application schematic is shown in

Figure 14 and Figure 15 for 1.35V and 5V

applications when low ESR caps are applied.

The typical performance and circuit waveforms

have been shown in the Typical Performance

Characteristics

section.

For

more

possible

applications of this device, please refer to related

Evaluation Board Data Sheets.