Bench Talk

Listen to the Music: Infineon MERUS^™ Audio Amplifier HAT ZW for Raspberry Pi Zero W

(Source: Andrey Suslov/Shutterstock.com)

Every time I sit down to write, I try to remember a famous saying attributed to American writer, humorist, entrepreneur, publisher, and lecturer Mark Twain (real name: Samuel Langhorne Clemens, 1835–1910). Twain purportedly said: “Write what you know.” Or, as sometimes I like to say, there are certain times when you have to listen to the music.

As a Senior Technology Specialist at Mouser Electronics, I know something about electronics. As a rock guitarist since the late 1970s, I know a few things about music and audio. And it recently turns out I know more than most about college algebra.

Over the summer, a colleague who works at a college reached out to me and said, “Hey, you are an engineer. You are probably pretty good at math.” I replied, “I use math all the time at work.” He said, “Great, can you teach college algebra this fall?”

After brushing up on my algebra, I am now an adjunct professor of college algebra well into my first semester. Next week’s lesson plans involve graphing circles. You might recall that specific formulas from geometry are useful in solving algebra problems (Table 1).

Table 1: The table lists some of the geometry formulas used in algebra.

The formulas all contain pi (π) (Figure 1). Pi is defined as the ratio of a circle's circumference to its diameter. So now, I am involved with teaching students lots of things related to pi.

Figure 1: Pi is a mathematical constant for the ratio of a circle’s circumference relative to its diameter. (Source: TotemArt/Shutterstock.com)

But speaking as a technical writer and engineer, I want to talk more about pi, but in a different manner. Let me take you from mathematical equations related to Pi to single-board computers (SBCs). All Raspberry Pi’s share a Broadcom system on a chip (SoC), Arm-based central processing units (CPUs), and an on-chip graphics processing unit (GPU) within them. Raspberry Pi Foundation released the Raspberry Pi Zero (2015) and Zero Wireless (W) (2017), which are built off the same small form factor and with a 40-pin general-purpose input/output (GPIO). Now let’s go back and talk more about pi with what else I know: electronics and audio.

One of the fastest-growing markets in electronics is for battery-powered smart speakers. All users desire extended playback time and smaller designs with improved audio performance. Infineon Technologies is a recognized leader in energy-efficient integrated audio amplifier solutions. Infineon Technologies MERUS™ Integrated Audio ICs offer revolutionary multilevel Class-D audio amplifier solutions with newly added high-performance products. MERUS™ is synonymous with unbeatable audio experience throughout premium Class-D audio applications. This technology offers advancements in terms of power efficiency, output power, and audio performance while ensuring fast time to market and design scalability.

Class D

While no one in my class wants to earn a D when studying about π, it is essential to understand what improvements and benefits Infineon is bringing to class-D audio amplifiers. Traditional class-D amplifiers present significant design challenges in compact applications such as portable consumer sound systems and smart speakers. These challenges include relatively low efficiency, high heat generation even at low to medium listening levels, and a need for bulky and costly filters to reduce out-of-band noise.

MERUS^™ Audio Amplifiers

Infineon Technologies MERUS^™ Audio Amplifiers are a relatively new range of class-D amplifiers that address these limitations using so-called multilevel amplification. This approach improves power consumption while inherently reducing interference and out-of-band noise. Also, manufacturing costs are reduced by eliminating or minimizing filters, which also helps save design space.

Infineon Technologies MERUS^™ Audio Amplifier HAT ZW (Figure 2) is a Class-D audio amplifier for the Raspberry Pi Zero W. The amplifier is a 100 percent self-contained Raspberry Pi audio HAT that offers high-definition audio at boom box power levels. The device is housed in a small form factor and brings Infineon proprietary multilevel technology to the Raspberry Pi. It is intended for loudspeaker building and wireless music streaming with minimum size and consumption, delivering state-of-the-art power efficiency and HD audio quality.

Figure 2: Infineon Technologies MERUS™ Audio Amplifier HAT ZW offers filter-free design, 5-level modulation, and best-in-class efficiency at normal listening levels. (Source: Mouser Electronics)

The Infineon MERUS™ Audio Amplifier HAT ZW, in conjunction with the Raspberry Pi, enables the rapid development of wireless music streaming while maximizing audio performance and power efficiency. They allow engineers the highest degree of design freedom for a wide range of audio solutions, including battery-operated speakers, voice-controlled active speakers, home theater systems, power-over-Ethernet (PoE), and multi-channel systems. So, skip the design and get to your development quicker so you can listen to music and do what you do best—engineer working solutions.