Previously, getting high-quality sound quality from audio amplifiers cost thousands of dollars and also relied on large, bulky, high-power Class A amplifiers. Now, the advent of GaN FETs and GaN ics ushered in the era of high-quality, low-cost Class D audio amplifiers.

The problem of using GaN to reduce distortion performance

    Historically, in order to meet the distortion performance targets (THD+N, TIM, and IM) required for high-quality sound, Class D amplifiers had to incorporate a large number of feedback circuits to compensate for poor open-loop performance. The source of this distortion is a silicon power MOSFET.

    The processor of a Class D amplifier produces a small high-frequency pulse width modulation (PWM) signal that represents the audio signal. In a half-bridge or full-bridge configuration, the power transistor converts the small signal into a large signal and passes it through a filter to drive the speaker. Since each pulse is a square wave, increasing the frequency can better represent the audio signal. During each switching cycle, the power supply dissipates through switching losses and conduction losses, thus balancing sound quality, operating frequency, and power consumption.
    The power stage goal of a Class D amplifier is to achieve accurate replication of a large signal from a small signal source while reducing heat dissipation. The superior switching and thermal properties of GAN-based FETs and ics produce waveforms that are closer to the desired ideal than those that can be achieved with silicon MOSFETs.

Premium Audio's Class D amplifiers with GaN technology offer superior sound quality to Class A amplifier designs

    GaN technology enables consumers to enjoy the benefits of Class D amplifiers over Class A amplifiers. More and more manufacturers are releasing designs based on gallium nitride. Premium Audio's Mini GaN 5 is a dual-channel gallium nitride balanced audio power amplifier. The amplifier has a power of 200W RMS (8 ohms) per channel. The Mini GaN 5 can also drive 4 ohm or even 2 ohm speakers. Despite its small size (9 ¾ "wide, 7" long, 1 ¾ "high), the sound quality is impressive. THD+N is about 0.006%, gain: low gain =26dB, medium gain =28dB, high gain =32dB.

EPC's eGaN FETs offer superior performance and high reliability
    Tom Rost, owner and chief designer of Premium Audio, selected EPC's eGaN® FETs for his GAN-based amplifiers because of their superior performance and high reliability. Tom Rost said, "EPC's gallium nitride products enable Premium Audio's GaN amplifiers to deliver a one-of-a-kind listening experience. Moreover, the eGaN FET not only delivers incredible performance, but also achieves the best price-performance ratio among audiophilist-grade amplifiers."
    Gallium nitride FETs and integrated chips have ushered in the era of high-quality, low-cost Class D audio amplifiers - providing superior sound quality and lower cost than Class A amplifiers. The superior switching performance of GaN FETs and integrated chips provides near-ideal waveforms, resulting in lower distortion and better sound quality than silicon MOSFETs. This performance heralds a new era of high-quality, affordable Class D audio amplifiers, bringing enthusiastic-quality amplifiers into consumer and automotive applications.