Circuit Operation (Handset); Outline; Power Supply Circuit/Reset Circuit - Panasonic KX-TGH262B Service Manual

KX-TGH260/KX-TGH262/KX-TGH263/KX-TGH264/KX-TGHA20/KX-TGA20
4.8.

Circuit Operation (Handset)

4.8.1.

Outline

Handset consists of the following ICs as shown in Block Diagram (Handset) (P.20).
• DECT BBIC (Base Band IC): IC1
- All data signals (forming/analyzing ACK or CMD signal)
- All interfaces (ex: Key, Detector Circuit, Charge, EEPROM, LCD)
• EEPROM: IC3
- Setting data is stored. (e.g. ID, user setting)
4.8.2.

Power Supply Circuit/Reset Circuit

Circuit Operation:
When powering on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6 V: BATT+) → F1 → BBIC (IC1) 32 pin
The Reset signal generates IC1 (71 pin) and 1.8 V.
VBAT
1.8 V
Reset (*RST)
(IC1_71 pin)
Start monitor
(IC1 50 pin)
(STM)
VBAT
BATTERY
2CELL
GND
1.8V
BBIC chip initialize
Charge Pump Output
For all peripherals
4.0V
3.0V 3.0V
4.0V 3.0V 3.0V
BBIC
4.0V
KEY LED
GND
22
3.0V 3.0V
EEPROM
1.8V
LCD