EVAL-ADMP504Z-FLEX AD [Analog Devices], EVAL-ADMP504Z-FLEX Datasheet - Page 7

• Manufacturer Part Number: EVAL-ADMP504Z-FLEX
• Description: Ultralow Noise Microphone
• Manufacturer: AD [Analog Devices]

Data Sheet
APPLICATIONS INFORMATION
The
microphone input (see Figure 8) or to a high input impedance
gain stage (see Figure 9). A 0.1 µF ceramic capacitor placed close
to the
mended 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 codec’s input impedance.
A minimum value of 2.2 μF is recommended in Figure 8
because the input impedance of the
can be as low as 2 kΩ at its highest PGA gain setting, which
would result in a high-pass filter corner frequency at about
37 Hz.
Figure 9 shows the
op amp configured as a noninverting preamplifier.
ADMP504
f
Figure 8.
C
ADMP504
= 1/(2π × C × R)
ADMP504
ADMP504
output can be connected to a dedicated codec
V
GND
supply pin is used for testing and is recom-
DD
ADMP504
OUTPUT
Connected to the Analog Devices
or
ADAU1361
MINIMUM
connected to an
2.2µF
0.1µF
Codec
ADAU1361/ADAU1761
MICBIAS
LINN
LINP
CM
ADAU1761
ADAU1361
OR
ADA4897-1
ADAU1761
Rev. 0 | Page 7 of 12
SUPPORTING DOCUMENTS
Evaluation Board User Guide
UG-325, EVAL-ADMP504-FLEX: Bottom-Ported Analog Output
Circuit Note
CN-0207, High Performance iMEMS Analog Microphone’s
Application Notes
AN-1003, Recommendations for Mounting and Connecting
AN-1068, Reflow Soldering of the MEMS Microphone
AN-1112, Microphone Specifications Explained
AN-1124, Recommendations for Sealing Analog Devices, Inc.,
MEMS Microphone Evaluation Board
Simple Interface to SigmaDSP Audio Codec
Analog Devices, Inc., Bottom-Ported MEMS Microphones
Bottom-Port MEMS Microphones from Dust and Liquid
Ingress
Figure 9.
ADMP504
GND
V
DD
OUTPUT
ADMP504
0.1µF
MINIMUM
Connected to the
V
REF
1µF
GAIN = (R1 + R2)/R1
10kΩ
R1
V
REF
R2
ADA4897-1
ADA4897-1
ADMP504
Op Amp
V
OUT