KX-TG8227UAB, KX-TG8227UAR, KX-TG8227UAW, KX-TGA820RUB, KX-TGA820RUR, KX-TGA820RUW, KX-TGA820UAB, KX-TGA820UAR, KX-TGA820UAW - Panasonic Telephone Service Manual (repair manual). Page 8

8

Base unit consists of the following ICs as shown in Block Diagram (Base Unit) (P.7).

• DECT BBIC (Base Band IC): IC7

- Handling all the audio, signal and data processing needed in a DECT base unit
- Controlling the DECT specific physical layer and radio section (Burst Module Controller section)
- ADPCM code filter for speech encoding and speech decoding (DSP section)
- Echo-cancellation and Echo-suppression (DSP section)
- Any tones (tone, sidetone, ringing tone, etc.) generation (DSP section)
- DTMF receiver (DSP section)
- Clock Generation for RF Module
- ADC, DAC, timer, and power control circuitry
- All interfaces (ex: RF module, EEPROM, LED, Analog Front End, etc.)

• RF Module: IC10

- PLL Oscillator
- Detector
- Compress/Expander
- First Mixer
- Amplifier for transmission and reception

• EEPROM: IC5

- Temporary operating parameters (for RF, etc.)

• FLASH MEMORY: IC11

- Voice Prompt (TAM) D/L Area
- ICM/OGM Recording Area

• TAM Companion: IC8

- Voice data compression and decompression
- Speaker Amp
- LED Driver

• Additionally,

- Power Supply Circuit (+3.3 V, +2.5 V, +1.8 V output)
- Crystal Circuit (10.368 MHz)
- Charge Circuit
- Telephone Line Interface Circuit