Description

The MT9092 HPhone-II is a fully featured integrated digital telephone circuit which includes an HDLC data formatter. Voice band signals are converted to digital PCM and vice versa by a switched capacitor Filter/Codec. The Filter/Codec uses an ingenious differential architecture to achieve low noise operation over a wide dynamic range with a single 5V supply. A Digital Signal Processor provides handsfree speaker-phone operation. The DSP is also used to generate tones (DTMF, Ringer and Call Progress) and control audio gains. Internal registers are accessed through a serial microport conforming to INTEL MCS-51™ specifications. The device is fabricated in Mitels low power ISO2-CMOS technology.

Features

• Programmable µ-Law/A-Law codec and filters

• Programmable CCITT (G.711)/sign-magnitude coding

• Programmable transmit, receive and side-tone gains

• DSP-based:

i) Speakerphone switching algorithm

ii) DTMF and single tone generator

iii) Tone Ringer

• Differential interface to telephony transducers

• Differential audio paths

• Single 5 volt power supply

• X.25 Level 2 HDLC data formatting

Applications

• Fully featured digital telephone sets

• Cellular phone sets

• Local area communications stations