Analog Devices EVAL-AD2437B1NZ User manual

EVAL-AD2437B1NZ Manual
Revision 2.1 , August 2023
Part Number
EVAL-AD2437B1NZ
Analog Devices, Inc.
One Technology Way
Norwood, MA 02062-9106

Copyright Information
© 2023 Analog Devices, Inc., ALL RIGHTS RESERVED. This document may not be reproduced in any form
without prior, express written consent from Analog Devices, Inc.
Disclaimer
Analog Devices, Inc. reserves the right to change this product without prior notice. Information furnished by Ana-
log Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its
use; nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under the patent rights of Analog Devices, Inc.
Trademark and Service Mark Notice
The Analog Devices logo, Blackfin, SHARC, A2B, SigmaDSP, SigmaStudio+, and EngineerZone are registered
trademarks of Analog Devices, Inc.
All other brand and product names are trademarks or service marks of their respective owners.
Regulatory Compliance
The EVAL-AD2437B1NZ evaluation board is designed to be used solely in a laboratory environment. The board is
not intended for use as a consumer-end product or as a portion of a consumer-end product. The board is an open
system design, which does not include a shielded enclosure and, therefore, may cause interference to other electrical
devices in close proximity. This board should not be used in or near any medical equipment or RF devices.
The EVAL-AD2437B1NZ evaluation board contains ESD (electrostatic discharge) sensitive devices. Electrostatic
charges readily accumulate on the human body and equipment and can discharge without detection. Permanent
damage may occur on devices subjected to high-energy discharges. Proper ESD precautions are recommended to
avoid performance degradation or loss of functionality. Store unused boards in the protective shipping package.
EVAL-AD2437B1NZ Manual ii

Contents
Preface
Purpose of This Manual.................................................................................................................................1–2
Manual Contents ........................................................................................................................................... 1–2
Technical Support.......................................................................................................................................... 1–3
Supported Integrated Circuit ......................................................................................................................... 1–3
Supported Tools............................................................................................................................................. 1–3
Product Information...................................................................................................................................... 1–3
Analog Devices Website.............................................................................................................................. 1–3
EngineerZone ............................................................................................................................................. 1–4
Using the Board
Product Overview .......................................................................................................................................... 2–1
Package Contents........................................................................................................................................... 2–1
Default Configuration ................................................................................................................................... 2–2
Reference Design Information .......................................................................................................................2–3
AD2437 - Audio Bus A2B Transceiver ........................................................................................................... 2–3
ADAU1701 SigmaDSP 28-/56-Bit Audio Processor with Two ADCs and Four DACs .................................. 2–3
ADM6315 - Open-Drain Microprocessor Supervisory Circuit ......................................................................2–4
BD28623MUV - Class D Speaker Amplifier ................................................................................................. 2–4
LT8609 - 2A/3A Peak Synchronous Step-Down Regulator with 2.5μA Quiescent Current............................ 2–4
MMICT390200012 - Digital Output MEMS Microphone........................................................................... 2–5
Hardware Reference
Switches......................................................................................................................................................... 3–1
I2C Bus Select ( S1)................................................................................................................................... 3–2
User I/O Port ( S2) .................................................................................................................................... 3–3
Connectors .................................................................................................................................................... 3–3
A2B ( P1 and P13) .................................................................................................................................... 3–4
EVAL-AD2437B1NZ Manual iii

Audio I2S Connector ( P2) ........................................................................................................................ 3–4
Class D Speaker Connectors ( P16-P18 ) ................................................................................................. 3–4
ADC Input Connector ( P4 ) ..................................................................................................................... 3–4
DAC Output Connector ( P6 and P7 ) .................................................................................................. 3–4
Multipurpose pins ( P5 ) ............................................................................................................................ 3–5
ADAU1701 I2C Signals ( P10 )................................................................................................................. 3–5
AD2437 SPI Connector ( P15).................................................................................................................. 3–5
Jumpers ......................................................................................................................................................... 3–5
Boot ( P9) .................................................................................................................................................. 3–6
Gain ( JP2)................................................................................................................................................ 3–6
AD2437 SIO0 SELECT ( JP1) ................................................................................................................. 3–7
Mute ( JP3) ............................................................................................................................................... 3–7
LEDs ............................................................................................................................................................. 3–7
3.3V ( DS1)................................................................................................................................................ 3–8
A2B Interrupt ( DS2).................................................................................................................................. 3–8
User I/O Status ( DS3) ............................................................................................................................... 3–8
Port Connection Status ( DS4, DS8, DS9 and DS12) ...................................................................... 3–9
Mute Status ( DS6)..................................................................................................................................... 3–9
Power Status LED Indicator ...................................................................................................................... 3–9
iv EVAL-AD2437B1NZ Manual

1 Preface
Thank you for purchasing the Analog Devices, Inc. EVAL-AD2437B1NZ evaluation board.
The EVAL-AD2437B1NZ is an evaluation board to evaluate various peripherals of the AD2437 A2B (Audio Bus)
transceiver. Refer to the datasheet/manual to get more details about the AD2437.
The EVAL-AD2437B1NZ is configured to be a Bus-Powered Sub (BPS) node. The EVAL-AD2437B1NZ can be
connected to a Main node, Local-Powered Sub (LPS) or a Bus-Powered Sub (BPS) node. These evaluation boards
are intended to be used with the SigmaStudio+®graphical development tool.
Block Diagram of Evaluation Board:
Figure 1-1: Block Diagram
Preface
EVAL-AD2437B1NZ Manual 1–1

A PC host controls the AD2437 A2B main transceiver I2C/SPI signals over the USB-to- I2C/SPI bridge; US-
Bi(EVAL-ADUSB2EB). This allows SigmaStudio+ to directly discover and control an A2B network as well as to
read back registers and monitor performance.
The SigmaStudio+®graphical development tool is the programming, development, and tuning software for the Sig-
maDSP, A2B, and Sharc processors. Familiar audio processing blocks can be wired together as in a schematic, and
the compiler generates DSP-ready code and a control surface for setting and tuning parameters. This tool allows
engineers with no DSP code writing experience to easily implement a DSP into their design and yet is still powerful
enough to satisfy the demands of experienced DSP designers. SigmaStudio+ links with both Analog Devices evalua-
tion boards and production designs to provide full in-circuit real-time IC control.
SigmaStudio+ includes an extensive library of algorithms to perform audio processing such as filtering, mixing, and
dynamics processing, as well as basic low-level DSP functions and control blocks. Advanced record-side processing
algorithms such as Enhanced Stereo Capture and wind noise detection are included in the standard libraries. Plug-in
algorithms from Analog Devices and 3rd party partners can be added to SigmaStudio+'s drag-and-drop library.
Along with its graphical DSP signal flow development, SigmaStudio+ also includes other features to speed up the
design cycle from product concept to release. SigmaStudio+ includes tools for intuitively setting control registers,
calculating tables of filter coefficients, visualizing filter magnitude and phase responses, generating C header files,
and sequencing a series of controls to ease your transition from SigmaStudio+ to system implementation on your
microcontroller.
Purpose of This Manual
This manual provides instructions for installing the product hardware (board). This manual describes the operation
and configuration of board components and provides guidelines for running code on the board.
Manual Contents
The manual consists of:
•Using the board
Provides basic board information.
•Hardware Reference
Provides information about the hardware aspects of the board.
•Bill of Materials
A companion file in PDF format that lists all of the components used on the board is available on the website
at https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/EVAL-
AD2437B1NZ.html.
•Schematic
Purpose of This Manual
1–2 EVAL-AD2437B1NZ Manual

A companion file in PDF format documenting all of the circuits used on the board is available on the website
at https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/EVAL-
AD2437B1NZ.html.
Technical Support
You can reach Analog Devices technical support in one of the following ways:
•Post your questions in the A2B support community at EngineerZone®:
http://ez.analog.com/a2b/
•Submit your questions to technical support directly at:
http://www.analog.com/support
•E-mail your questions about A2B transceiver applications and SigmaStudio+ to:
[email protected]
•Contact your Analog Devices sales office or authorized distributor. Locate one at:
http://www.analog.com/adi-sales
Supported Integrated Circuit
This evaluation system supports the Analog Devices AD2437 IC.
Supported Tools
Information about SigmaStudio+ and the A2B software plug-in for the EVAL-AD2437B1NZ evaluation board is
available at: www.analog.com/SigmaStudio+.
Product Information
Information about the AD2437 product family is available at: www.analog.com/A2B
Analog Devices Website
The Analog Devices website, http://www.analog.com, provides information about a broad range of products - ana-
log integrated circuits, amplifiers, converters, transceivers, and digital signal processors.
Also note, MyAnalog.com is a free feature of the Analog Devices website that allows customization of a web page to
display only the latest information about products you are interested in. You can choose to receive weekly e-mail
notifications containing updates to the web pages that meet your interests, including documentation errata against
all manuals. MyAnalog.com provides access to books, application notes, data sheets, code examples, and more.
Technical Support
EVAL-AD2437B1NZ Manual 1–3

Visit MyAnalog.com to sign up. If you are a registered user, just log on. Your user name is your e-mail address.
EngineerZone
EngineerZone is a technical support forum from Analog Devices, Inc. It allows you direct access to ADI technical
support engineers. You can search FAQs and technical information to get quick answers to your embedded process-
ing and DSP design questions.
Use EngineerZone to connect with other DSP developers who face similar design challenges. You can also use this
open forum to share knowledge and collaborate with the ADI support team and your peers. Visit http://
ez.analog.com to sign up.
Product Information
1–4 EVAL-AD2437B1NZ Manual

2 Using the Board
This chapter provides information on the major components and peripherals on the board, along with instructions
for installing and setting up the emulation software.
Product Overview
The board features:
•Analog Devices AD2437 - Audio Bus A2B Transceiver
•Audio
•Analog Devices ADAU1701 SigmaDSP 28-/56-Bit Audio Processor with Two ADCs and Four DACs
•Rohm Semiconductor BD28623MUV - Class D Speaker Amplifier
•Four Stereo MMICT390200012 - Digital Output MEMS Microphone
•EEPROM
•Three 3.5mm audio jacks
•A2B
•Two XLR connectors
•LEDs
•Nine LED's
•Switches
•Three switches: Reset, SCL/SDA Select, and SIO2
Package Contents
Your EVAL-AD2437B1NZ package contains the following items.
•EVAL-AD2437B1NZ board
•A2B Software - Online Request Documentation
Using the Board
EVAL-AD2437B1NZ Manual 2–1

•XLR Cable
Contact the vendor where you purchased your EVAL-AD2437B1NZ evaluation board or contact Analog Devices,
Inc. if any item is missing.
Default Configuration
The Default Hardware Setup figure shows the default settings for jumpers and switches and the location of the
jumpers, switches, connectors, and LEDs. Confirm that your board is in the default configuration before using the
board.
P17
P16
P18
P19
P4
P7
P6
DS10
DS1
DS2
DS3
P2
P9
JP1
P1 P13
DS4
DS8 DS12
DS9
S1
S2
DS5
P10
P5
DS11
DS6
JP2 JP3
P15
Figure 2-1: Default Hardware Setup
Default Configuration
2–2 EVAL-AD2437B1NZ Manual

Reference Design Information
A reference design info package is available for download on the Analog Devices Web site. The package provides
information on the schematic design, layout, fabrication, and assembly of the board.
The information can be found at:
https://www.analog.com/en/design-center/evaluation-hardware-and-software/evaluation-boards-kits/EVAL-
AD2437B1NZ.html
AD2437 - Audio Bus A2B Transceiver
The AD2437 provides a multi-channel, I2S/TDM link over distances of up to 30 m between nodes. It embeds bi-
directional synchronous pulse-code modulation (PCM) data (for example, digital audio), clock, and synchronization
signals onto a single differential wire pair. A2B supports a direct point to point connection and allows multiple, dai-
sy-chained nodes at different locations to contribute and/or consume time division multiplexed channel content.
A2B is a single-main, multiple-sub system where the transceiver at the host controller is the main node and generates
clock, synchronization, and framing for all sub nodes. The main A2B device is programmable over a control bus
(I2C and SPI) for configuration and read back. An extension of this control bus is embedded in the A2B data
stream, which grants direct access of registers and status information on sub transceivers as well as I2C and SPI com-
munication over distance.
The transceiver can connect directly to general-purpose digital signal processors (DSPs), field-programmable gate
arrays (FPGAs), application specific integrated circuits (ASICs), microphones, analog-to-digital converters (ADCs),
digital-to-analog converters (DACs), and codecs through a multi-channel I2S/TDM interface. It also provides a
pulse density modulation (PDM) interface for direct connection of up to four PDM digital microphones.
Finally, the transceiver also supports an A2B bus powering feature, where the main node supplies voltage and current
to the sub nodes over the same daisy-chained, twisted pair cable as used for the communication link. Please refer to
the datasheet for more details.
ADAU1701 SigmaDSP 28-/56-Bit Audio Processor with Two
ADCs and Four DACs
The ADAU1701 is a complete single-chip audio system with a 28-/56-bit audio DSP, ADCs, DACs, and microcon-
troller-like control interfaces. Signal processing includes equalization, crossover, bass enhancement, multiband dy-
namics processing, delay compensation, speaker compensation, and stereo image widening. This processing can be
used to compensate for real-world limitations of speakers, amplifiers, and listening environments, providing dramat-
ic improvements in perceived audio quality.
Its signal processing is comparable to that found in high end studio equipment. Most processing is done in full 56-
bit, double precision mode, resulting in very good low level signal performance. The ADAU1701 is a fully
Reference Design Information
EVAL-AD2437B1NZ Manual 2–3

programmable DSP. The easy to use SigmaStudio+™ software allows the user to graphically configure a custom sig-
nal processing flow using blocks such as biquad filters, dynamics processors, level controls, and GPIO interface con-
trols.
ADAU1701 programs can be loaded on power-up either from a serial EEPROM through its own self-boot mecha-
nism or from an external microcontroller. On power-down, the current state of the parameters can be written back
to the EEPROM from the ADAU1701 to be recalled the next time the program is run.
Two Σ-ΔADCs and four Σ-ΔDACs provide a 98.5 dB analog input to analog output dynamic range. Each ADC
has a THD + N of −83 dB, and each DAC has a THD + N of −90 dB. Digital input and output ports allow a
seamless connection to additional ADCs and DACs. The ADAU1701 communicates through an I2C bus or a 4-
wire SPI port.
ADM6315 - Open-Drain Microprocessor Supervisory Circuit
The ADM6315 is a reliable voltage-monitoring device that is suitable for use in most voltage-monitoring applica-
tions.
The ADM6315 is designed to monitor as little as a 1.8% degradation of a power supply voltage. The ADM6315
can monitor all voltages (at 100 mV increments) from 2.5 V to 5 V.
Included in this circuit is a debounced manual reset input. RESET can be activated using an ordinary switch (pull-
ing MR low), a low input from another digital device, or a degradation of the supply voltage.
The manual reset function is very useful, especially if the circuit in which the ADM6315 is operating enters into a
state that can be detected only by the user. Allowing the user to reset a system manually can reduce the damage or
danger that could otherwise be caused by an out-of-control or locked-up system.
BD28623MUV - Class D Speaker Amplifier
The BD28623MUV is a Class D Speaker Amplifier designed for Flat-panel TVs in particular for space-saving and
low-power consumption. This IC delivers an output power of 20W+20W.
LT8609 - 2A/3A Peak Synchronous Step-Down Regulator with
2.5μA Quiescent Current
The LT8609 is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that
consumes only 1.7μA of non switching quiescent current. The LT8609 can deliver 2A of continuous current with
peak loads of 3A (<1sec). Burst Mode operation enables high efficiency down to very low output currents while
keeping the output ripple below 10mVP-P. A SYNC pin allows synchronization to an external clock, or spread spec-
trum modulation for low EMI operation. Internal compensation with peak current mode topology allows the use of
small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V
threshold and can be used to program VIN UVLO or to shut down the part. A capacitor on the TR/SS pin
ADM6315 - Open-Drain Microprocessor Supervisory Circuit
2–4 EVAL-AD2437B1NZ Manual

programs the output voltage ramp rate during start-up while the PG flag signals when VOUT is within ±8.5% of
the programmed output voltage as well as fault conditions.
MMICT390200012 - Digital Output MEMS Microphone
The T3902 is a low‐power, low‐noise digital MEMS microphone in a small package. The T3902 consists of a
MEMS microphone element and an impedance converter amplifier followed by a fourth‐order Σ‐Δmodulator. The
pulse density modulated (PDM) interface allows two microphones to be time multiplexed on a data line using a
single clock.
MMICT390200012 - Digital Output MEMS Microphone
EVAL-AD2437B1NZ Manual 2–5

3 Hardware Reference
This chapter describes the hardware design of the EVAL-AD2437B1NZ.
Switches
This section describes operation of the switches. The switch locations are shown in the Switch Locations figure.
Hardware Reference
EVAL-AD2437B1NZ Manual 3–1

S1
S2
Figure 3-1: Switch Locations
I2C Bus Select ( S1)
The I2C Bus Select switch isolates the 1701 I2C bus from the A2B I2C bus. The table below shows the default
configuration, for more information about I2C clock routing, refer to schematic.
Switch Position I2C clock routing
1A/1B ON I2C from AD2437 (DEFAULT)
2A/2B OFF I2C from ADAU1701
3A/3B ON I2C from AD2437 (DEFAULT)
4A/4B OFF I2C from ADAU1701
Switches
3–2 EVAL-AD2437B1NZ Manual

User I/O Port ( S2)
General purpose momentary push button connected to SIO2. There is also a corresponding LED that can be driven
from SIO2. Please see PRM for SIO2 configuration.
Switch Port
S2 SIO2
Connectors
This section describes connector functionality and provides information about mating connectors. The connector
locations are shown in the Connector Locations figure.
P17
P16
P18
P19
P4
P7
P6
P2
P1 P13
P10
P5
P15
Figure 3-2: Connector Locations
Switches
EVAL-AD2437B1NZ Manual 3–3

A2B ( P1 and P13)
P13 is used to connect towards the next sub board and P1is used to connect towards the main board. These con-
nectors allow the AD2437 on the EVAL board to talk to other A2B devices on the bus.
Part Description Manufacturer Part Number RefDes
3 pole XLR receptacle Neutrik NC3FAH2-LR-DAE
NC3MAH-LR
P1 - female
P13 - male
Mating Cable
XLR cable assembly
Audio I2S Connector ( P2)
Multipurpose connector containing all a combination of SIO, clock, and GPIO signals.
Class D Speaker Connectors ( P16-P18 )
P16-P18 are the outputs of the Class - D amplifier and are used to connect stereo speakers to the board. Please
ensure that the chosen speaker is no less than 8 ohms.
Connector Speaker Side
P16 SPKR L-
P17 SPKR L+
P18 SPKR R-
P19 SPKR R+
ADC Input Connector ( P4 )
The ADAU1701 has two Σ-ΔADCs. P4 will supply both signals through a 3.5mm Stereo TRS connector. The
signal-to-noise ratio (SNR) of the ADCs is 100 dB, and the THD + N is −83 dB.
Part Description Manufacturer Part Number
3.5mm Stereo TRS connector CUI Devices SJ-3523-SMT
DAC Output Connector ( P6 and P7 )
The ADAU1701 includes four Σ-ΔDACs. The SNR of the DAC is 104 dB, and the THD + N is −90 dB. A full-
scale output on the DACs is 0.9 V rms (2.5 V p-p). The DACs are in an inverting configuration. If a signal inver-
sion from input to output is undesirable, it can be reversed either by using an inverting configuration for the output
filter or by simply inverting the signal in the SigmaDSP program flow.
Connectors
3–4 EVAL-AD2437B1NZ Manual

Part Description Manufacturer Part Number
3.5mm Stereo TRS Connector CUI Devices SJ-3523-SMT
Multipurpose pins ( P5 )
Bi-directional pins designed for multipurpose use. For further information please refer to the schematic.
ADAU1701 I2C Signals ( P10 )
P10 is an I2C header compatible with the USBi adapter for direct programming of the ADAU1701 through Sig-
maStudio+.
AD2437 SPI Connector ( P15)
P15 provides access to the AD243x SPI port for interfacing with external peripherals. The connector has 0.1" head-
ers. The pinouts can be found in the schematic.
Jumpers
This section describes functionality of the configuration jumpers. The Jumper Locations figure shows the jumper
locations.
Connectors
EVAL-AD2437B1NZ Manual 3–5

P9
JP1
JP2 JP3
Figure 3-3: Jumper Configurations
Boot ( P9)
The Boot jumper allows the ADAU1701 to perform a self boot, in which it loads its RAM and register settings from
an external EEPROM. When the jumper is installed no self boot operation is initiated. When the jumper is re-
moved a self boot operation is initiated the next time there is a rising edge on the RESET signal of the ADAU1701.
This jumper is installed by default.
Gain ( JP2)
Gain terminal sets the gain of the amplifier. Please set GAIN after setting MUTE low. A pop noise may occur if
GAIN is set while MUTE is high.
Jumpers
3–6 EVAL-AD2437B1NZ Manual

GAIN GAIN setting
OFF (DEFAULT) 17dB
ON 20dB
AD2437 SIO0 SELECT ( JP1)
The SIO0 Select jumper is used to select SIO0 source for AD2437. For PDM microphone signal, jumper must be
between 1 and 2. For SIO0 signal from ADAU1701, jumper should be on 2 and 3. The default position is 1 and 2.
Jumper Routing
1 and 2 (DEFAULT) PDM OUT
2 and 3 ADAU1701_MP6
Mute ( JP3)
This jumper is used to mute the Class - D amplifier.
Jumper MUTE setting
1 and 2 (DEFAULT) OFF
2 and 3 ON - Controlled by ADR1
LEDs
This section describes the on-board LEDs. The LED Locations figure shows the LED locations.
Jumpers
EVAL-AD2437B1NZ Manual 3–7