Circuit Operation (Handset) - Panasonic KX-TG5771BXS Service Manual

4.8.

Circuit Operation (Handset)

4.8.1. Construction
The circuit mainly consists of DSP and RF part as shown in the block diagram.
4.8.1.1. DSP: IC201
Function
• Battery Low, Power down detect circuit
• Ringer Generation
• Interface circuit
RF part, Speaker, Mic, LED, Key scan, LCD, Headset
Initialize
Note:
(*1) The initializing time of the DSP chip is 20 ms under normal conditions.
4.8.1.2. RF part
Mainly voice signal is modulated to RF, or it goes the other way.
4.8.1.3. EEPROM: IC241
All setting data is stored.
ex: ID code, user setting (Phonebook, Caller ID data)
4.8.1.4. FLASH MEMORY: IC246
Following information data is stored.
• Ringer melody
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KX-TG5771BXS/KX-TGA570BXS