FLY EZZY - Baseband Circuit and Power Systems

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 MT6223A and periphery components, main function as below:
A.
B.
C.
2.8V-5.5V Input Range
Charger input up to 8V
Seven LDOs optimized for specific GSM Sub-systems
D.
E.
One LDO for RF transceiver
High operation efficiency and Low stand-by current
F. Li-Ion battery charge function
G. SIM Card interface
H. Two open-drain output switches to control the LED and vibrator
I. Three NMOS switches to control RGB LEDs
J. Thermal Overload Protection
K. Under Voltage Lock-out Protection
I. Over Voltage Protection
M. Power-on Reset and Start-up Timer