ADMP421

Rev. 0 | Page 8 of 16

PCB LAND PATTERN LAYOUT

The recommended PCB land pattern for the ADMP421 should

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

package, as shown in Figure 8. Care should be taken to avoid

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

solder paste stencil pattern layout is shown in Figure 9. The

diameter of the sound hole in the PCB should be larger than the

diameter of the sound port of the microphone. A minimum

diameter of 0.5 mm is recommended.

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

Figure 8. Suggested PCB Land Pattern Layout

1.45

0.9

2.45

0.7

1.525

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

Figure 9. Suggested Solder Paste Stencil Pattern Layout