PSB 4860

General General Combined with an analog front end the PSB 4860 provides a solution for embedded or stand alone answering machine applications. Together with a standard microcontroller for analog telephones these two chips form the core of a featurephone with full duplex speakerphone and answering machine capabilities.

The chip PSB 4860 features recording by DigiTape™, a family of high performance algorithms. Messages recorded with DigiTape™ can be played back with variable speed without pitch alteration. Messages recorded with a higher bitrate can be converted into messages with a lower bitrate arbitrarily. Current members of DigiTape (TM) span the range from 3.3 kbit/s to 10.3 kbit/s.

Furthermore the PSB 4860, V2.1 has a full duplex speakerphone, a caller ID decoder, DTMF recognition and generation and call progress tone detection. The frequency response of cheap microphones or loudspeakers can be corrected by a programmable equalizer.

Messages and user data can be stored in ARAM/DRAM or flash memory which can be directly connected to the PSB 4860. The PSB 4860 also supports a voice prompt EPROM for fixed announcements.

The PSB 4860 provides an IOM®-2 compatible interface with two channels for speech data.

Alternatively to the IOM®-2 compatible interface the PSB 4860 supports a simple serial data interface (SSDI) with separate strobe signals for each direction (linear PCM data, one channel).

A separate interface is used for a glueless connection to the PSB 4860.

The chip PSB 4860 is programmed by a simple four wire serial control interface and can inform the microcontroller of new events by an interrupt signal. For data retention the PSB 4860 supports a power down mode where only the real time clock and the memory refresh (in case of ARAM/DRAM) are operational.

The PSB 4860 supports interface pins to +5 V levels.