Panasonic KX-TG2448BXF Service Manual

Contents

9.3. Signal Flowchart in the Whole SystemReceptionCN101 of the Base Unit is connected to the TEL line, and signal is enter through the bridge diode D101. While talking, the relay(Q141) is turned ON and amplified at the Q171, then led to DSP (IC501). The DSP encodes ADPCM and TDD/TDMA withFHSS to TX-DATA. The TX-DATA signal is enter to IC901 of RF PART, and modulated to 2.4GHz. The RF signal is fed intoTx/Rx switch (D904). The RF signal is passed through filter (FL901) and fed to ANTENNA.As for the Handset, RF signal from the antenna passes through filter (FL901), then is routed by Tx/Rx switch (D904) and ledto IC901. The RF signal is amplified by LNA and down-converted to IF signal in IC901. The IF signal passing through internalfilter is demodulated into RXDATA, then enter to DSP (IC201). The DSP performs TDD/TDMA and ADPCM decoding to convertthe RXDATA into the voice signal, then it is output to the speaker.TransmissionThe voice signal entering from the Handset microphone is led to DSP (IC201). The DSP encodes ADPCM and TDD/TDMA withFHSS to TX-DATA. The TX-DATA signal enters to IC101 of RF PART, and is modulated to 2.4GHz. The RF signal is fed intoTx/Rx switch (D904). The RF signal is passed through filter (FL901) and fed to ANTENNA.As for the Base Unit, RF signal from the antenna passes through filter (FL901), then is routed by Tx/Rx switch (D904) and ledto IC901. The RF signal is amplified by LNA and down-converted to IF signal in IC901. The IF signal passing through internalfilter is demodulated into RXDATA, then enter to DSP (IC501). The DSP performs TDD/TDMA and ADPCM decoding to convertthe RXDATA into the voice signal. The voice signal is amplified at the TX amplifier (Q161), then output to the TEL line CN101through the relay (Q141) and bridge (D101).46KX-TG2448BXF / KX-TG2448BXS / KX-TGA254BXF / KX-TGA254BXS