Power Supply Circuit/Reset Circuit - Panasonic KX-TG4221N 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
VDDC (1.2 V)
VBAT
IC302
3.0V
RSTN(Reset)
REGULATOR
STM/CKM
VBAT
Reset (RSTN)
(IC501_54 pin)
Startmonitor
(IC501 57pin)
(CKM/STM)
KX-TG4221N/KX-TG4222N/KX-TG4223N/KX-TG313SK/KX-TG4224N/KX-TG4225N/KX-TGA421N
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
BBIC chip initialize
13
+3.0V
IC601
FLASH
IC611
EEPROM
Receive
Amp.