UMTS/HSPA Module Series
UG95 Hardware Design
UG95_Hardware_Design Confidential / Released 28 / 72
Module
VBAT_RF
VBAT_BB
VBAT
C1
100uF
C6
100nF
C7
33pF
C8
10pF
+
+
C2
100nF
C5
100uF
C3
33pF
C4
10pF
D1
5.1V
Figure 7: Star Structure of the Power Supply
3.6.3. Reference Design for Power Supply
The power design for the module is very important, since the performance of power supply for the module
largely depends on the power source. The power supply is capable of providing the sufficient current up to
2A at least. If the voltage drop between the input and output is not too high, it is suggested that a LDO
should be used to supply power for module. If there is a big voltage difference between the input source
and the desired output (VBAT), a buck converter is preferred to be used as a power supply.
The following figure shows a reference design for +5V input power source. The designed output for the
power supply is about 3.8V and the maximum load current is 3A.
DC_IN
C1
C2
MIC29302WU
U1
IN
OUT
E
N
G
N
D
A
D
J
2
4
1
3
5
VBAT
100nF
C3
470uF
C4
100nF
R2
100K
47K
R3
470uF
470R
51K
R4
R1
1%
1%
MCU_POWER
_ON/OFF
47K
4.7K
R5
R6
Figure 8: Reference Circuit of Power Supply
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