Figure 9: Vbat Input Application Circuit - SimCom SIM5215 Hardware Design

There are three sections about how to design and optimize users' power systems.
Power supply circuit
We recommend DCDC or LDO is used for the power supply of the module, make sure that the peak
current of power components can rise up to more than 2A. The following figure is the reference design of
+5V input power supply. The designed output for the power supply is 4.1V; here a linear regulator can be
used.
If there is a big difference between the input voltage and the desired output (VBAT), a switching converter
power will be preferable because of its better efficiency, especially at the high current situation. The
following figure is the reference circuit. Note that DCDC may deprave RF performance because of ripple
current intrinsically.
SIM5215&SIM5216_Hardware Design_V2.02
VBAT
VBAT
VBAT
GND
VBAT
VBAT
VBAT
GND

Figure 9: VBAT input application circuit

Figure 10: Reference circuit of the LDO power supply
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Smart Machine Smart Decision
VBAT
2012-08-31