The AS3435 and AS3415 ANC speaker drivers from ams AG are designed for a new generation of noise cancellation stereo headsets with zero audible hiss. The new drivers are also what the company states are the industry’s first ANC (active noise cancellation) ICs to feature integrated bypass switches, offering headset manufacturers the freedom to create sleeker – and cheaper – industrial designs.
The AS3435, for feedback systems, and AS3415, for feed-forward systems incorporate new ultra-low noise amplifiers with a 900nV input referred noise floor. the devices are the first ANC speaker drivers to produce no audible high-frequency hiss when paired with low-noise microphones. Manufacturers of audiophile products can replace existing ANC solutions with the AS3435 and AS3415 to provide 35mW stereo output power with THD+N of 0.1% into a 32Ω load and a typical signal-to-noise ratio of >110dB.
The AS3435 and AS3415 feature integrated bypass switches, so that the music signal coming from the 3.5mm audio jack may be routed through the ANC chipset without any power source connected to the device. By eliminating the external switch, this feature helps to reduce bill-of-materials cost and the size of the PCB, as well as relieving the designer of the need to accommodate a mechanical switch on the headset’s housing.
The devices’ analog implementation of noise cancellation provides for power consumption often two or three times lower than equivalent digital solutions. Featuring typical power consumption of 10mW at 1.5V in noise cancellation mode, either device can support operation for more than 100 hours from a single AAA battery. In the AS3435 and AS3415, ams has also added a new bass boost equalization capability, eliminating the need for a discrete signal processing IC to perform equalization functions.