Data Sheet

ADMP521

Rev. A | Page 11 of 16

PCB DESIGN AND LAYOUT

The recommended PCB land pattern for the ADMP521 should

be laid out to a 1:1 ratio to the solder pads on the microphone

package, as shown in Figure 15. Take care to avoid applying solder

paste to the sound hole in the PCB. A suggested solder paste

stencil pattern layout is shown in Figure 16.

The response of the ADMP521 is not affected by the PCB hole

size as long as the hole is not smaller than the sound port of the

microphone (0.25 mm, or 0.010”, in diameter). A 0.5 mm to 1 mm

(0.020 inch to 0.040 inch) diameter for the hole is recommended.

Take care to align the hole in the microphone package with the

hole in the PCB. The exact degree of the alignment does not affect

the microphone performance as long as the holes are not partially

or completely blocked.

4× 0.40 × 0.60

(0.30)

0.90

(0.30)

ø1.70

3.80

(0.30)

0.35

2.80

2× R0.10

(0.30)

0.35

2.05

0.70

ø1.10

(1.000)

(0.550)

CENTER LINE

Figure 15. Suggested PCB Land Pattern Layout

1.45

0.9

2.45

0.7

1.525

1.000

0.35

1.849

1.849

1.498

0.205 WIDE

0.248 × 0.498 (2×)

0.248 × 1.148 (2×)

0.248 × 0.948 (2×)

1.498 × 0.248

0.398 × 0.298 (4×)

0.362 CUT (3×)

1.17

24°

24°

0.375

CENTER

LINE

Figure 16. Suggested Solder Paste Stencil Pattern Layout