Infineon Audiohub Nano Analog User manual

Please read the Important Notice and Warnings at the end of this document
www.infineon.com page 1 of 9 2022-07-28
Infineon Audiohub Nano Analog
User Manual
About this document
Scope and purpose
The user manual provides information about using and evaluating Infineon analog XENSIVTM MEMS
microphones with the help of the Audiohub Nano Analog evaluation board. It familiarizes you with the
evaluation board and guides you through the initial set-up and measurement.
Intended audience
Design, verification, test and software engineers can use this document to get an understanding of the
functionality and connections of the Audiohub Nano evaluation board.
Table of contents
About this document....................................................................................................................... 1
Table of contents............................................................................................................................ 1
1Introduction .......................................................................................................................... 2
1.1 Prerequisites............................................................................................................................................2
1.1.1 Hardware............................................................................................................................................2
1.1.2 Software .............................................................................................................................................2
2Features................................................................................................................................ 3
2.1 Summary of features...............................................................................................................................3
2.2 Block diagram..........................................................................................................................................3
3Initial set-up.......................................................................................................................... 4
3.1 USB communication ...............................................................................................................................4
3.2 Audacity software set-up ........................................................................................................................4
4Evaluation board information.................................................................................................. 5
4.1 Connectors ..............................................................................................................................................5
4.2 Test points...............................................................................................................................................6
4.3 Volume Unit (VU) meter display with onboard LEDs .............................................................................7
4.4 Operating mode and gain configuration with mode switch..................................................................7
Revision history.............................................................................................................................. 8

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1Introduction
This document serves as a manual for the evaluation of up to two Infineon analog XENSIVTM MEMS microphones
using the Audiohub Nano evaluation board. The evaluation board provides a USB audio interface to stream
audio data from microphones with any audio recording and editing software.
1.1 Prerequisites
1.1.1 Hardware
•Infineon Audiohub Nano Analog evaluation board
•Infineon analog XENSIVTM MEMS microphone flex kit
•Micro-USB cable
1.1.2 Software
•Audio editing software that supports 48 kHz and 24-bit recording
•FT9xx programming utility for firmware update (optional)
Figure 1 Audiohub Nano Analog with left and right flex connectors for analog XENSIVTM
MEMS Microphones

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2Features
2.1 Summary of features
•Audio interface for analog XENSIVTM MEMS microphones
•Audio streaming over USB interface
•48 kHz sampling rate
•24-bit audio data (stereo)
•Dynamic range 120dB
•Two different power modes (high power and low power mode, see section 4.4)
•Four different gain configurations indicated by onboard LEDs (see section 4.4)
•Volume unit meter indication by onboard LEDs (see section 4.3)
•Powered through Micro-USB
2.2 Block diagram
Figure 2 Audiohub Nano Analog block diagram

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3Initial set-up
To get started insert the analog XENSIVTM MEMS Microphones from your flex kit to the flex connectors (left and
right), as shown in Figure 1.
3.1 USB communication
The evaluation board is powered via the Micro-USB port. Connect the board to a host computer via USB. For
streaming the audio data from the board select the AudioHubNano2A as your audio input device. Any audio
recording or editing software (e.g. Audacity) can be used to record and evaluate the microphones, see Figure 3.
3.2 Audacity software set-up
Audacity is a free and open-source audio editor and recording application. Select the audio source as Audiohub
Nano in the recording software, as shown in Figure 3. The recording channel can be selected as either mono or
stereo.
Figure 3 Recording from Audiohub Nano Analog in Audacity

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4Evaluation board information
Figure 4 AudioHub Nano Analog Layout
4.1 Connectors
A list of the connecters provided by on the Audiohub Nano evaluation board can be found in Table 1.
Furthermore, Table 2 gives an overview of the respective pins.
Table 1 Connector list
Reference designator
Description
LEFT
Flex connector and pinheader for left channel microphone connection
RIGHT
Flex connector and pinheader for right channel microphone connection
PROG
Programming connector
USB
Micro-USB connector for power and audio streaming
Table 2 Connector X3 detailed pinout
Pin number
Name
Description
2
VMIC
Microphone VDD
4
IN+
Positive analog output of microphone
6
IN-
Negative analog output of microphone
1, 3, 5
MGND
Microphone ground
The pinout of the pinheaders can be found on the back of the circuit board.
The inputs IN+ and IN- are using a DC offset, provided by the MEMS microphones. Please note, without this DC
offset the Audiohub Nano Analog does not work correctly.

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4.2 Test points
Table 3 lists all the available test points for debugging on the Audiohub Nano evaluation board.
Table 3 Test point description
Test point
Description
12MHz
12 MHz from oscillator Q1
25MHz
24.576 MHz clock of oscillator Q1 for I2S interface
3V3
3.3 V digital power rail
4V
4.0 V analog power rail
VMIC
Microphone power supply
GND
Digital ground

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4.3 Volume Unit (VU) meter display with onboard LEDs
The onboard LEDs turn on based on the measured sound pressure levels (dB SPL). The LEDs work as a volume
unit (VU) meter when streaming the audio data. The threshold for the LED turn-on is based on the sound
pressure level during the audio streaming, as shown in Table 4. In case only one microphone is connected both
LED bars will indicate the volume of the mono audio stream.
Table 4 VU meter setting based on sound pressure level
LED reference
dB SPL
dBFS
LED color
D1, D2
50
-80
green
D3, D4
65
-65
green
D5, D6
80
-50
green
D7, D8
94
-36
yellow
D9, D10
110
-20
orange
D11, D12
125
-5
red
4.4 Operating mode and gain configuration with mode switch
The mode switch push button S1 can be used to switch through various configurations in a sequence. The
settings are defined for configuring the power modes:
•normal mode and
•low power mode.
The mode switch button also enables different pre-defined gain configurations on the audio data stream. The
gain settings can be configured when the evaluation board is in idle mode and not recording the audio stream.
On power-on, the evaluation board is set to normal mode with 0 dB gain by default. This configuration is
indicated by LED D3.
Table 5 describes the different gain configurations and power modes that can be changed with the mode
switch push button.
Table 5 Operating mode and gain configuration LED reference
LED reference
Operating mode
Gain configuration (dB)
D3
Normal power mode
VDD of microphone at 2.75 V
0
D5
12
D7
18
D9
24
D4
Low power mode
VDD of microphone at 1.60 V
0
D6
12
D8
18
D10
24

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Revision history
Document
version
Date of release
Description of changes
V1_0
2022-07-20
Initial release
V1_1
2022-07-28
Included layout

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Edition 2022-07-28
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