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SIM5360_Hardware Design_V1.06
2016-11-17
21
3
Application Interface Specification
3.1
Power Supply
The power supply pins of SIM5360 include four VBAT pins (pin 62&63, pin 38&39). VBAT directly
supplies the power to RF circuit and baseband circuit. All four VBAT pins of SIM5360 must be used
together. VBAT directly supplies the power to RF PA and baseband system. For the VBAT, 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 more than 2A.
The following figure is the VBAT voltage ripple wave at the maximum power transmit phase.
The test condition: VBAT =4.0V, VBAT maximum output current =2A, C
A
=100 µF tantalum capacitor
(ESR=0.7Ω) and C
B
=1µF(Please refer to Figure 8
—
Application circuit).
577us
4.615ms
Burst:2A
I
VBAT
VBAT
Max:200mV
Figure 7: VBAT voltage drop during burst emission (GSM/GPRS)
3.1.1
Power Supply Pin
Four VBAT pins are dedicated to connect the supply voltage.
Table 6: Pin description
Pin type
Pin name
Min
Typ
Max
Unit
POWER
VBAT
3.4
3.8
4.2
V
3.1.2
Design Guide
Make sure that the input voltage at the VBAT pin will never drop below 3.3V even during a transmit burst
when the current consumption rises up to more than 2A. If the power voltage drops below 3.3V, the
module may be shut down automatically. Using large tantalum capacitors (above 100uF) will be the best
way to reduce the voltage drops. If the power current cannot support up to 2A, users must introduce larger
capacitor (typical 1000uF) to storage electric power, especially GPRS multiple time slots emission.
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CONFIDENTIAL
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