DA6251.002

27 October, 2017

17 (21)

PRINTED CIRCUIT BOARD (PCB) LAYOUT CONSIDERATIONS

In PCB layout design the input (CIN) and output (COUT) capacitors should be placed as close to the MAS6251

(U1) as possible and routed with low inductance connection to ground plane. See figure 17 below for a PCB layout

example of figure 3 application circuit which includes output voltage adjustment resistors R1 and R2.

Figure 17. PCB layout example

Table 6. PCB layout example component details

Ref

Manuf. part

Value

Rating

Case

inch (metric)

Dimensions

(LxWxT)

U1

MAS6251AA1Q13

MAS6251

QFN-16 3x3

3.0x3.0x0.75 mm

L1

LQM2MPN2R2MEH

2.2

H

0.7A (Isat)

0806 (2016)

2.0x1.6x0.7 mm

CIN

GRM188R60J106KE47D

10

F

6.3V (X5R)

0603 (1608)

1.6x0.8x0.9 mm

COUT

C0603X5R1E104K030BB

100nF

25V (X5R)

0201 (0603)

0.6x0.3x0.3 mm

CS

470pF

25V (X5R)

0201 (0603)

0.6x0.3 mm

RB

33k



0201 (0603)

0.6x0.3 mm

RF

1.5M



0201 (0603)

0.6x0.3 mm

R1

274k



0201 (0603)

0.6x0.3 mm

R2

10M



0201 (0603)

0.6x0.3 mm