Cirrus Logic's CS6422 Full-Duplex Speakerphone IC is an enhanced speakerphone IC that enables full-duplex conversation using echo cancellation and suppression in a single-chip solution. The CS6422 can easily replace existing half-duplex speakerphone ICs with a huge increase in conversation quality. The CS6422 consists of telephone & audio interfaces, two codecs and an echo-cancelling DSP. Most modern speakerphones use half-duplex operation, which alternates transmission between the far-end talker and the speakerphone user. This is done to ensure stability because the acoustic coupling between the speaker and microphone is much higher in speakerphones than in handsets where the coupling is mechanically suppressed.
Cirrus Logic's CDB6422 Evaluation Board provides an easy platform to evaluate the performance of the CS6422 echo cancelling IC in a target system. To facilitate evaluation, the board provides a wide selection of network interfacing options (analog telephone line, μ-law/a-law PCM data, or analog RCA jack). The analog interfaces support both fixed and variable gain options to allow for level-matching with target hardware. The board includes a keypad and a DTMF generator to enable dialing on standard analog telephone systems. The board can operate from a single +12V power supply and can be used in a stand-alone configuration allowing for easy testing in car cellular hands-free applications.