Nuvoton NAU83U25YG automotive-grade, Class-D audio amplifier

Nuvoton’s NAU83U25YG automotive-grade Class-D audio amplifier, featuring high-efficiency stereo and digital input, delivers up to 3 W (4Ω load) or 1.7 W (8Ω load) output power. Featuring a two-wire gain adjustment interface, it is suitable for automotive electronics applications such as dashboards, eCall and T-Box systems.

Nuvoton strictly adheres to automotive industry standards, offering AEC-Q100 qualified products for automotive applications. To simplify system design, the company’s products support digital I²S audio signal input from the vehicle’s main controller, reducing the need for external components and minimising PCB size. Additionally, its digital amplifiers help prevent circuit interference and effectively solve EMI issues.

Class-D topology represents a leap forward in both power efficiency and noise minimisation in audio devices, according to Nuvoton. By generating a binary square wave, Class-D amplifiers efficiently amplify the signal through power device switching. Class-D amplifiers thus offer power efficiencies that are two-thirds better than Class-AB devices, the company claims, with the NAU83U25YG having 90% efficiency.

The amplifier eliminates the need for an external output filter, due to its spread-spectrum-oscillator technology and slew-rate control, effectively reducing EMI. Moreover, it offers enhanced immunity and power supply rejection ratio (PSRR) of >80 dB at 217 Hz, making it suitable for wireless and AM frequency band applications. Other features include ultralow quiescent current (ie, 2.1 mA at 3.7 V for two channels), low distortion, low background noise and wide dynamic range.

The amplifier can drive a 4Ω load with a high output power of up to 3 W and fast start-up time of just 14 ms. Additionally, it supports comprehensive device protection (overcurrent protection, undervoltage lockout, overtemperature protection, clock termination protection).