Motorola Mobility LLC T56KT1 User Manual

Page of 116
Power Supply
12
 G30 - Module Hardware Description
December 15, 2009
Power Supply
The G30 power supply must be a single external DC voltage source of 3.3V to 4.2V. The power 
supply must be able to sustain the voltage level during a GSM transmit burst current surge, which 
may reach 2.0A.
The G30 interface contacts for the main power supply, are described in 
. All these 
contacts must be used for proper operation.
Power Supply Design
Special care must be taken when designing the power supply of the G30. The single external DC 
power source indirectly supplies all the digital and analog interfaces, but also directly supplies the 
RF power amplifier (PA). Therefore, any degradation in the power supply performance, due to 
losses, noises or transients, will directly affect the G30 performance.
The burst-mode operation of the GSM transmission and reception, draws instantaneous current 
surges from the power supply, which causes temporary voltage drops of the power supply level. 
The transmission bursts consume the most instantaneous current, and therefore cause the largest 
voltage drop. If the voltage drops are not minimized, the frequent voltage fluctuations may 
degrade the G30 performance.
Table 2-2: Power Supply Signals
Pin #
(LGA interface)
Pin #
(70 pin 
connector 
interface)
Signal Name
Description
65, 67-77
1-4
GND
Main ground connection for G30 
module.
78, 79
5-8
VCC
DC supply input for G30 module.
V
IN
 = 3.3 V to 4.2 V
I
RMS 
= 350 mA during multislot 
transmission
I
MAX  
= 2 A during transmit 
bursts