Power Supply Circuit/Reset Circuit - Panasonic KX-TG6841B Service Manual

4.4.4.

Power Supply Circuit/Reset Circuit

The power supply voltage from AC adaptor is converted to VBAT (3.0V) in IC302. And +3.0V for peripherals and analog part is
insulated from VBAT by Doubler of BBIC.
Circuit Operation:
5.5V
AC Adaptor
LCD_BLT (IC501-pin 33)
VBAT
VDDC (1.2 V)
Reset (RSTN)
(IC501_54 pin)
Startmonitor
(IC501 57pin)
(CKM/STM)
VBAT
IC302
3.0V
RSTN(Reset)
REGULATOR
STM/CKM
Q661
BBIC chip initialize
KX-TG6841B/KX-TG6842B/KX-TG6843B/KX-TG6844B/KX-TG6845B/KX-TG6873B/KX-TGA680B
IC501
VBAT
pin 15
pin 10
DOUBLER OUT
For peripherals
BBIC
pin 54
VDDC (1.2V)
pin 57
pin 9
RF Part
ANS LED
MSG LED
SP LED
LCD BLT
13
+3.0V
IC601
FLASH
IC611
EEPROM
Receive
Amp.
LCD