Read Panasonic KX-TG8521RUB / KX-TG8522RUB / KX-TGA850RUB Service Manual online
13
KX-TG8521RUB/KX-TG8522RUB/KX-TGA850RUB
4.5.
Circuit Operation (Handset)
4.5.1.
Outline
Handset consists of the following ICs as shown in Block Diagram (Handset) (P.11).
• DECT BBIC (Base Band IC): IC1
- All data signals (forming/analyzing ACK or CMD signal)
- All interfaces (ex: Key, Detector Circuit, Charge, EEPROM, LCD)
- All interfaces (ex: Key, Detector Circuit, Charge, EEPROM, LCD)
• EEPROM: IC3
- Setting data is stored. (e.g. ID, user setting)
4.5.2.
Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6 V: BATT+)
BATTERY(2.2 V ~ 2.6 V: BATT+)
→ F1 → BBC1 (IC1) 10 pin
The Reset signal generates IC1 (54 pin) and 1.8 V.
Startmonitor
(IC1 57pin)
VDDC (1.2 V)
VBAT
Reset (RSTN)
(IC1_54 pin)
(IC1_54 pin)
BBIC chip initialize
(CKM/STM)
GND
BATTERY
2CELL
2CELL
BBIC
3.0V
3.0V
DOUBLER OUT (Charge Pump)
For all peripherals
For all peripherals
3.0V
3.0V
EEPROM
GND
LCD BACKLIT LED
KEY LED
4.0V
GND
4.0V
GND
BELL
3.0V
4.0 output
External Charge Pump
Circuit or IC
4.0V
VBAT
VBAT
VDDC (1.2V)
3.0V
3.0V
LCD
Click on the first or last page to see other KX-TG8521RUB / KX-TG8522RUB / KX-TGA850RUB service manuals if exist.