Panasonic KX-TG4753B Service Manual

Also see for KX-TGA405B: Service manual Service manual

Contents

Panasonic KX-TG4753B Service Manual Manual pdf 11 page image

11KX-TG4753B/KX-TG470B/KX-TGA405B4.4. Circuit Operation (Base Unit)General Description:(BBIC, Flash Memory, EERROM) is a digital speech/signal processing system that implements all the functions of speechcompression, record and playback, and memory management required in a digital telephone answering machine.The BBIC system is fully controlled by a host processor. The host processor provides activation and control of all that functionsas follows.4.4.1. BBIC (Base Band IC: IC501)• Voice Message Recording/Play backThe BBIC system uses a proprietary speech compression technique to record and store voice message in Flash Memory.An error correction algorithm is used to enable playback of these messages from the Flash Memory.• DTMF GeneratorWhen the DTMF data from the handset is received, the DTMF signal is output.• Synthesized Voice (Pre-recorded message)The BBIC implements synthesized Voice, utilizing the built in speech detector and a Flash Memory, which stored the vocabulary.• Caller ID demodulationThe BBIC implements monitor and demodulate the FSK/DTMF signals that provide CID information from the Central Office.• Digital SwitchingThe voice signal from telephone line is transmitted to the handset or the voice signal from the handset is transmitted to theTelephone line, etc. They are determined by the signal path route operation of voice signal.• Block Interface CircuitRF part, LED, Key scan, Speaker, Telephone line.4.4.2. Flash Memory (IC601)Following information data is stored.• Voice signalex: Pre-recorded Greeting message, Incoming message4.4.3. EEPROM (IC611)Following information data is stored.• Settingsex: message numbers, ID code, Flash Time, Tone/PulseRF partADPCMAnalogFrontEnd&Multi-plexerTELLineInterfaceDigitalSpeechProcessorCaller IDModemDigital TAM SystemFlash Memory IC601Host CPUBBIC (IC501)DECT RF systemTDMA/TDDMod/DemodPA/LNA ADPCMKeys/ LEDs/ ChargeEEPROM IC611