3.2Principle of base band circuit
3.2.1 Whole introduction of base band circuit
3.2.2 Explanation of power circuit and in-and-out circuit
Power source is provided by MTK MT6253 and periphery components, main function as below:
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
I.
M.
2.8V-5.5V Input Range
Charger input up to 8V
Seven LDOs optimized for specific GSM Sub-systems
One LDO for RF transceiver
High operation efficiency and Low stand-by current
Li-Ion battery charge function
SIM Card interface
Two open-drain output switches to control the LED and vibrator
Three NMOS switches to control RGB LEDs
Thermal Overload Protection
Under Voltage Lock-out Protection
Over Voltage Protection
Power-on Reset and Start-up Timer
MT6253
UnRegister
ed