ML7021 pdf datasheet (Echo Can

The ML7021 is an improved version of the MSM7602 with the reduced cancelable echo delay TIme and addiTIonal 2100Hz tone detecTIon funcTIon. The ML7021 is a low-power CMOS device for canceling echo (in an acoustic system or telephone line) generated in a speech path. Echo is canceled, in digital signal processing, by estimating the echo path and generating a pseudo echo signal. The ML7021 makes possible a quality conversation by controlling the noise level and preventing howling with howling detector, double talk detector, attenuation function, and a gain control function. The devise also controls the low level noise with a center clipping function. Further, the ML7021 I/O interface supports m-law PCM . The use of a single chip CODEC, such as the MSM7566/7704 (3 V) or MSM7543/7533 (5 V), allows a simplified and efficient echo canceler configuration.