Hardware+Design V1.07

Table Of Contents
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3 Application Interface Specification
3.1 Power Supply
The power supply pins of SIM5320 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 4.615msmay cause voltage drop, and the current consumption rises
typically to peak of more than 2A. So the power supply must be able to provide sufficient current up to
more than 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=0.7) and C
B
=1µF(Please refer to Figure 8Application circuit).
Figure 8: VBAT_RF voltage drop during burst emission (GSM/GPRS)
3.1.1 Power Supply Pin
Two VBAT_RF and two VBAT_BB pins are dedicated to connect the supply voltage.
Table 5: Pin description
Pin type Pin name Min Typ Max Unit
VBAT_RF 3.3 3.8 4.2 V
POWER
VBAT_BB 3.3 3.8 4.2 V
Note: 1.Though the VBAT_RF and VBAT_BB are supplied by the same voltage level, they are different pins. VBAT_RF
is for RF section and VBAT_BB is for baseband system.
2. When the module is power off, users must pay attention to the issue about current leakage. Refer to Chapter 3.10.2
Note2.
SIM5320_Hardware Design_V1.07 2012-09-21
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