The global audio amplifiers market is projected to reach almost USD 4.6 billion by 2026, at a CAGR of 5.5% compared to 2020, according to Market Research Future. The demand for speakers with high-quality sound and the requirement for electronic products with power efficiency fuel this market, and in smart home and automotive applications, the Class-D amplifiers grow the most rapidly due to their high power efficiency with fidelity improvement.
Various headphone amplifiers, including EPISODE I, Shark Audio, and Eagle T, are provided by Hi-Professional Technology. The Class-A EPISODE I, with 3W output power at 32Ω, has an ESS9018S DAC chip and a femtosecond-level noise oscillator built in. It supports DSD up to 11.2MHz and PCM up to 384kHz. Shark Audio has an AK4452 DAC and an SSM6322 amp chip built in and supports DSS 256 and PCM up to 384kHz. Eagle T has a 32bit 384kHz Burr Brown D/A (digital to analog) converter built inside. It can receive digital audio signals through a USB interface or a coaxial/optical input. All three amplifiers provide a great listening experience for the audience.
Class-AB Audio Amplifier Series
A Class-AB audio amplifier has both the advantages of Class-A and Class-B amplifiers: high efficiency and fidelity. The high efficiency comes from the “push-pull” design of two transistors, one for amplifying the positive voltage, and the other for amplifying the negative voltage. The better part of Class-AB amplifiers is the transition between the two transistors is smoother, so the distortion of sound is less serious than in Class-B amplifiers.
Nuvoton ISD8101SYI is a 1.5W Class-AB audio amplifier with 100 dB SNR (signal to noise ratio) and 2.4～6.8V operating voltage. With lower than 1μA standby current and 0.5ms start-up time, ISD8101SYI is designed with a chip-enabled pin to further improve its efficiency. It also has the current limiting function to avoid any over-current situation. The pop-and-click from standby is as low as 10 mV in both single-ended and differential conditions. In brief, ISD8101SYI Class-AB audio amplifier is suitable for game consoles, POS machines, weight scales, and portable electronic products.
Class-D Audio Amplifier Series
The working principle of Class-D amplifiers differs from Class-A, B, or AB amplifiers. Class-D amplifiers have a high-frequency PWM circuit to modulate an AC input signal into DC pulses, and this process makes amplification ultra-efficient. Nuvoton NAU82011 and NAU8325YG are mono and stereo Class-D audio amplifiers, respectively. Both have great THD+N and EMI performance and can operate between -40～85°C.
With pop-and-click suppression, low standby current, and 4ms start-up time, the filter-free Nuvoton NAU82011YG is designed with a chip-enabled pin to improve its efficiency. The operating voltage of NAU82011YG ranges from 2.5 to 5.5V, and its output power is up to 2.9W with the capability of driving a 4Ω load. The quiescent current is around 1.2mA and 1.7mA at 3.6V and 5V, respectively. NAU82011YG mono Class-D amplifier is suitable for smartphones, tablet PCs, personal navigation devices, and portable audio devices.
|Output Power (W)||Condition|
|2.9||4Ω at 5V, 10% THD+N|
|2.3||4Ω at 5V, 1% THD+N|
|1.7||8Ω at 5V, 10% THD+N|
|1.38||8Ω at 5V, 1% THD+N|
|1.48||4Ω at 3.6V, 10% THD+N|
|1.2||4Ω at 3.6V, 1% THD+N|
|0.88||8Ω at 3.6V, 10% THD+N|
|0.71||8Ω at 3.6V, 1% THD+N|
NAU8325YG stereo Class-D amplifier offers I²S audio input and I²C control with lower than 2μA standby current. The operating voltage of NAU8325YG ranges from 2.5 to 5.5V, and its output power is up to 3W with the capability of driving a 4Ω load. High efficiency, low quiescent current, 18μVRMS output noise (at 0dB gain), and 80dB PSRR make it a great choice for various applications. NAU8325YG stereo Class-D amplifier is suitable for notebooks, tablet PCs, digital camcorders, gaming controllers, personal media players, and wireless headsets (VR).
|Quiescent Current (mA)||Condition|
|2.1 (2 ch)||3.7V|
|3.2 (2 ch)||5V|
|Output Power (W)||Condition|
|3 (2 ch)||4Ω at 5V, 10% THD+N|
|1.72 (2 ch)||8Ω at 5V, 10% THD+N|
|1.32 (2 ch)||4Ω at 3.7V, 1% THD+N|
|0.75 (2 ch)||8Ω at 3.7V, 1% THD+N|
Smart Amp Series
Both Nuvoton NAU83G10 and NAU83G20 are mono Class-D smart amplifiers with integrated KCS (Klippel Controlled Sound) technology to deal with signal distortion, heating, and other negative influences. The KCS algorithm, invented by audio test equipment provider Klippel, uses a nonlinear speaker model to make the signal fidelity and sound quality better. The operating voltage of NAU83G10VG ranges from 2.9 to 5.5V with the output power of 8W at 4Ω and 6.5W at 8Ω; while the operating voltage of NAU83G20VG is up to 14V with the output power of 20W at 4Ω and 11W at 8Ω. They both support I²C, I²S, PCM, and TDM interfaces, and are designed with Cadence Tensilica HiFi Audio DSP core.
The related evaluation boards for NAU83G10 and NAU83G20 are NM-N83G10MA/MB/SA/SB and NM-N83G20MA/SA. These platforms not only provide the hardware, but also offer DB-Lab software (from Klippel), A6 audio enhancements, and NAU83G10/NAU83G20 Labview GUI. Besides, reference speakers will be included but the power supply will not. Overall, they are great for designers to emulate the systems in the initial stage.
Audio Amplifiers at TECHDesign
No matter whether you are searching for an audio amplifier product or any audio amplifier ICs, you can get what you want at TECHDesign. EPISODE I, Shark Audio, and Eagle T headphone amplifiers from Hi-Professional Tech. offer an extraordinary listening experience; Class-AB, Class-D audio amplifier ICs, and evaluation boards of the smart amp series from Nuvoton provide great components and tools for designers. Come visit TECHDesign immediately and start selecting the products right for you!