User's Manual

Smart Machine Smart Decision
SIM5320_Hardware Design_V1.01 2011-11-10
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2.4 Footprint Recommendation
Figure 6: Footprint recommendation (Unit: mm)
3 Application Interface Specification
3.1 Power Supply
The power supply pins of SIM5320AD include VBAT_RF and VBAT_BB. VBAT_RF directly supplies
the power to RF PA; VBAT_BB supplies the power to the baseband system. For the VBAT_RF, the ripple
due to GSM/GPRS emission burst (every 4.615ms）may cause voltage drop, and the current consumption
rises typically to peak of 2A. So the power supply must be able to provide sufficient current up to 2A. The
following figure is the VBAT_RF voltage ripple wave at the maximum power transmit phase.
The test condition: VBAT_RF=4.0V, VBAT maximum output current =2A, C
A
=100 µF tantalum capacitor
(ESR=0.7Ω) and C
B
=1µF(Please refer to Figure 36—Application circuit).