DocID023777 Rev 2

5/19

AN4184

Microphone measurements

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reference microphone is an analog device, the analog interface of the STSmartVoice has to

be used in order to ensure synchronous measurements (refer to AN4146 for details on

using the board).

Table 1 summarizes the main features and corresponding values of the three MEMS

microphones, followed by figures showing the frequency response of each device.

Figure 4. MP45DT02 frequency response (STEVAL-MKI129V1)

Table 1. Main parameters of ST’s digital MEMS microphones

Features

ST MEMS MP45DT02

ST MEMS MP34DB01

ST MEMS MP34DT01

Sensitivity

-26 dBFS

-26 dBFS

-26 dBFS

S/N

61 dB

62 dB

63 dB

Directivity

OMNI directional

OMNI directional

OMNI directional

Lead free reflow issue

no

no

no

Current consumption

20 µA (sleep)

650 µA

20 µA (sleep)

600 µA

20 µA (sleep)

600 µA

Package dimensions

4.72 x 3.76 x 1.25 mm

3 x 4 x 1 mm

3 x 4 x 1 mm

Operating temperature

-40°C < T < +85°C

-30°C < T < +85°C

-30°C < T < +70°C

-30

+30

-25

-20

-15

-10

-5

+0

+5

+10

+15

+20

+25

d

B

V

20

20k

50

100

200

500

1k

2k

5k

10k

Hz

Helmotz frequency (Peak is

just beyond the audio band)