LTE-A Module Series
EM120R-GL&EM160R-GL Hardware Design
EM120R-GL&EM160R-GL_Hardware_Design 24 / 79
circuit of VCC.
Module
VCC
VCC
C1
220
μ
F
+
D1
5.1 V
C2
1
μ
F
C3
100 nF
C4
33 pF
C5
10 pF
Figure 4: Reference Circuit of VCC
3.3.2. Reference Design for Power Supply
Power design for the module is very important, as the performance of the module largely depends on the
power source. The power supply can provide sufficient current (at least 2.5 A). If the voltage drop between
the input and output is not too high, an LDO is suggested to be used to supply power for the module. If
there is a big voltage difference between the input source and the desired output (VCC), a buck converter
is preferred to be used as the power supply.
The following figure shows a reference design for +5 V input power source. The typical output of the
power supply is about 3.7 V and the maximum load current is 3 A.
LDO_IN
C1
C2
MIC29302WU
U1
IN
OUT
E
N
G
N
D
A
D
J
2
4
1
3
5
VCC
100nF
C3
470
μ
F
C4
100nF
R2
1
0
0
K
1
%
5
1
K
1
%
R3
470
μ
F
470R
R4
R1
MCU_POWER
_ON/OFF
47K
4.7K
R5
R6
C5
C6
33pF
10pF
TVS
D1
Figure 5: Reference Design of Power Supply