An echo cancellation and noise suppression algorithm is presented by using improved adaptive step-size non-linear filter technology

and a single-chip implementation for this algorithm is proposed.This chip is fabricated in a 3.3V/1.8V 6-metal 180 nm mixed-signal CMOS process

and its acoustic echo cancellation performance can reach 70 dB

noise suppression performance is 20 dB and side tone cancellation is 30 dB.This chip includes a 16-bit DSP

three 14-bit sigma-delta ADC

two 16-bit sigma-delta DAC and embedded ROMs and RAMs

which also provides USB

UART

I

2

C and PCM interfaces.Experimental results show that the chip supports full-duplex mode

faraway hand-free function and dual microphones input and it complies with ITU-T G.165 standard. With very low power consumption

simple peripheral circuits a

nd strong self adaptation capability

it can be widely used in various applications such as portable Bluetooth hand-free car kit

GPS and instant communication.