INMP510

APPLICATIONS INFORMATION

CONNECTING TO AUDIO CODECS

The output of the INMP510 can be connected to a dedicated codec microphone input (see Figure 9) or to a high input impedance

gain stage (see Figure 10). A 0.1 µF ceramic capacitor placed close to the INMP510 supply pin is used for testing and is

recommended to adequately decouple the microphone from noise on the power supply. A DC blocking capacitor is required at the

output of the microphone. This capacitor creates a high-pass filter with a corner frequency at

where R is the input impedance of the codec.

A minimum value of 2.2 μF is recommended in Figure 9 because the input impedance of codecs can be as low as 2 kΩ at their

highest PGA gain setting, which results in a high-pass filter corner frequency at 37 Hz. Figure 10 shows the INMP510 connected to an

op amp configured as a noninverting preamplifier.

Figure 9. INMP510 Connected to a Codec

Figure 10. INMP510 Connected to an Op Amp

GAIN = (R1 + R2)/R1

INMP510

GND

OUTPUT

1µF

MINIMUM

0.1µF

10k

Ω

R1

R2

VDD

AMP

1.8-3.3 V

ADC

OR

CODEC

INMP510

GND

OUTPUT

INPUT

MICBIAS

2.2 µF

MINIMUM

0.1 µF

VDD

Page 8 of 13

Document Number: DS-INMP510-00

Revision: 1.0.