A High-Performance Feedback FxLMS Active Noise Cancellation VLSI Circuit Design for In-Ear Headphones

Abstract

Active noise cancellation (ANC) applications for headphones are strongly influenced by practical constraints. Most previous works developing algorithms for ANC headphones are based on simplified simulations only and neglect practical limitations. However, we find that the influence of circuit delay on the overall noise reduction is very critical when developing ANC headphones. Such influence becomes even more severe in developing the ANC in-ear headphone due to its tiny volume. Moreover, power consumption is still significant in modern portable ANC devices since the ANC systems dissipate a significant amount of energy in their batteries. This paper aims to deal with above challenges for ANC in-ear headphones. To achieve this objective, we design a dedicated VLSI hardware architecture with high-performance/low-power considerations. This new approach allows ANC controllers to be operated at lower operating frequency, which results in lower power consumption, and facilitates higher noise canceling performance than that achieved by conventional ANC headphones. Experimental results show that the feedback FxLMS ANC prototype in-ear headphone achieves 15 dB noise reduction and up to 600 Hz attenuation bandwidth. Moreover, the proposed design consumes only 0.58 mW with 0.6 V, 1.40 mW with 0.7 V, and 5.78 mW with 0.9 V, respectively, to satisfy ANC application requirements with the sampling rates of 48, 96, and 192 kHz.