“Lowering both power and noise are essential in the fast-moving, highly competitive market for consumer and portable devices,” said Farid Noory, senior product marketing manager at Nuvoton.

“Our engineers, therefore, spearheaded an intensive effort to define a new generation of Class-D amplifiers – the NAU8214 – designed to address the market’s need for power consumption and reduced switching noise, while delivering an array of other experience-enriching features.”

The NAU8214 mono Class-D audio amplifier sets a new standard in audio amplifiers by offering a unique VCC independent power limiting feature, unlike any other power limiting class-D devices in the market which have a supply voltage dependency, especially when the limit goes up with the supply.

NAU8214 solves customers’ problems in silicon, specifically for those who are troubled with return of damaged products. Moreover, NAU8214 can satisfy requirements such like sourcing speakers from different suppliers to deal with various tolerances, aiming at optimal loudness in audio output and yet simultaneously taking the durability (of speakers) into consideration, and even for customers who use 4 Ohm and 8Ohm speakers with power limits of 1,2 & 3W. This new amplifier’s inputs can be configured in either single-ended or differential mode.

The NAU8214 has a unique feature that limits the Maximum output power delivered to the load. This Max power limit is set by using external resistor connected to the dedicated pin PLMT. Once the threshold is set, the NAU8214 will not allow the voltage output more than the set value irrespective of the input supply voltage variations. Because of this output voltage control, the NAU8214 is able to achieve power limit function for any given load.

The NAU8214 amplifier does not need an external output filter, as each reduces electromagnetic interference (EMI) through spread-spectrum-oscillator technology and slew-rate control. Moreover, the NAU8214 provides improved immunity and power supply rejection ratio, or PSRR, of > 90dB at 217Hz, making the devices ideal Class-D audio amplifiers for wireless and AM frequency band applications.

The Class D topology represents a significant leap forward in both power efficiency and noise minimization in audio devices. Class D amplifiers generate a square wave, making the wave-form binary so that it can be amplified by switching the power devices. The power efficiencies of Class D amplifiers are two-thirds better than those of Class AB devices.

The Class D NAU8214 is capable of driving a 4Ω load with up to 2.9W output power, and features a chip-enable pin for extremely low standby current and fast start-up time of 4ms.