Mono digital audio amplifier based on NS4158

Functional Description

NS4158 is a 5W high-efficiency mono digital audio amplifier with anti-distortion function, ultra-low EMI, no filter required. The unique anti-distortion function can detect the distortion of the output signal and dynamically adjust the system gain, which not only effectively prevents the damage to the speaker caused by overload output, but also brings a comfortable listening experience. In actual application, the amplifier can be set to work in anti-distortion mode and normal mode through software or hardware. The software is controlled by one-line pulse, and the hardware is controlled by level. The application is very flexible. NS4158 adopts advanced technology to greatly reduce EMI interference within the full bandwidth and minimize the impact on other components. Its output does not require a filter. The PWM modulation structure and the built-in feedback resistor reduce external components, PCB area and system cost. At a working voltage of 5V, NS4158 can provide 5W output power to a 2Ω load.

NS4158 has built-in over-current protection, over-heat protection and under-voltage protection functions, which effectively protect the chip from being damaged under abnormal working conditions. And the new circuit design is fully optimized by using spread spectrum technology, with an efficiency of more than 90%, which is more suitable for low-voltage, high-power output audio systems.

The NS4158 is available in SOP8 package and is rated for operation over the -40°C to 85°C temperature range.

Key Features

• Anti-distortion function, software or hardware setting working mode

• Output power: 3.0W (4Ω load), 3.8W (3Ω load), 5.0W (2Ω load)

• Operating voltage range: 3V～5.25V

• 0.5%THD (1W output power, 5V supply, 4Ω load)

• Excellent full bandwidth EMI suppression capability

• Excellent "power-on, power-off" noise suppression

• Up to 90% efficiency

• High PSRR: -80dB (217Hz)

• Overcurrent protection, overheat protection, undervoltage protection

• SOP8 package

Application Areas

• USB 2.1 Speakers

• Card 2.1 speakers, mobile 2.1 speakers

• For boxes, ordinary card speakers