AN 2007 PL88 2007 102945 Application note for KIT ARDMKR AMP 40W Design of an Arduino compatible audio amplifier platform About this document Scope and purpose This document describes the design principles of an audio amplifier platform that is compatible with Arduino 2 boards supporting I S audio playback. More specifically, this application note will discuss the design of the KIT ARDMKR AMP 40W board on both hardware (PCB design) and firmware (Arduino code). The board contains Infineons MA12070P multilevel amplifier, which will be discussed in more detail. The content should enable both professional engineers as well as DIYs to build prototypes, reproduce the design, or pick up the design for further development as part of the product design process. The design is generic in principle and can 2 be used in combination with any audio board that supports I S audio playback. Intended audience This document is intended for anyone interested in building audio systems, professional engineers, DIYs or for educational purposes. Table of contents About this document ....................................................................................................................... 1 Table of contents ............................................................................................................................ 1 1 Introduction .......................................................................................................................... 2 2 General overview ................................................................................................................... 4 2.1 Board overview ........................................................................................................................................ 4 2.2 System overview ..................................................................................................................................... 5 2.3 Features and electrical specifications .................................................................................................... 6 3 Hardware design .................................................................................................................... 7 3.1 Schematic ................................................................................................................................................ 7 3.1.1 Power and board interface ................................................................................................................ 8 3.1.2 Boost converter .................................................................................................................................. 8 3.1.3 Class D amplifier and configuration .................................................................................................. 9 3.2 PCB design ............................................................................................................................................. 11 3.3 Bill of materials ...................................................................................................................................... 15 4 Firmware ............................................................................................................................. 17 4.1 Start-up .................................................................................................................................................. 17 4.2 Main ....................................................................................................................................................... 17 4.3 Volume control ...................................................................................................................................... 18 Revision history............................................................................................................................. 19 Application Note Please read the Important Notice and Warnings at the end of this document V 1.0 www.infineon.com/kit-ardmkr-amp-40w page 1 of 20 2020-07-20 Application note for KIT ARDMKR AMP 40W Design of an Arduino-compatible audio amplifier platform Introduction 1 Introduction The Arduino project started in 2005 as a student program at the Interaction Design Institute Ivrea, in Ivrea, Italy, aiming to provide an affordable and easy way to create devices that interact with their environment while using advanced microprocessors, controllers, sensors and transducers. Since 2005, Arduino boards have been steadily growing in popularity among makers and DIY enthusiasts, who have developed a broad range of projects, from gaming consoles and drone controls to various smart home automation projects. Arduino boards are based on open-source hardware and software, licensed under the GNU Lesser General Public License (LGPL) or the GNU General Public License (GPL), enabling board manufacturing and software distribution by anyone. This extends the development of high-performance embedded computing power to a much wider audience including people without alo professional hardware or software background. When looking at the types of DIY projects, it is interesting to see that many revolve around audio connectivity, e.g., IoT audio interaction or stand-alone audio players. Until recently it was necessary to add several separate boards or shields together to realize such a system. This has changed since the release of the MKR family, where Arduino has now added audio features such as an 2 I S bus, SD card audio read/write and Alexa voice-control compatibility. This also makes the Arduino platform a perfect demonstration vehicle for Infineons high-performance integrated class D audio ICs. By releasing a fully compatible amplifier board with enough output power to drive a variety of speakers all with best-in-class audio performance, low power consumption and high efficiency Infineon is providing yet another useful building block in the Arduino ecosystem. The Infineon Arduino board has the following key parameters and features: TM Equipped with MERUS MA12070P proprietary multilevel amplifier Power input: 5 V/2.5 A sourced from the same single USB-C power supply or battery pack No need for external or extra power supplies Up to 40 W instantaneous peak output power with a USB-C power supply or battery pack Compatible with Arduino MKRZERO and MKR1000 Wi-Fi Full hardware control, customization and error monitoring through the Arduino programming framework Application Note 2 of 20 V 1.0 2020-07-20