LTE-A Module Series
EM06 Series Hardware Design
EM06_Series_Hardware_Design 24 / 69
Module
VCC
VCC
C1
220 uF
+
D1
5.1 V
C2
1 uF
C3
100 nF
C4
33 pF
C5
10 pF
Figure 4: Reference Design of VCC
3.4.2. Reference Design of Power Supply
Power design is critical as the module’s performance largely depends on its power source. The power
supply should be capable of providing a sufficient current of 2 A at least. If the voltage drop between the
input and output is not too big, it is suggested that an LDO is used while supplying power for the module;
If there is a big voltage difference between the input source and the desired output (VCC = 3.7 V Typ.), a
buck DC-DC converter is preferred.
The following figure shows a reference design of a +5 V input power source with the DC-DC TPS54319.
The typical output of the power supply is about 3.7 V and the maximum load current is 3 A.
D1
TVS
PWR_IN
C8
220
μ
F
C11
10 pF
C10
33 pF
C9
100 nF
+
R1
205k
U1
Q1
NPN
R8
47k
R7
4.7k
PWR_EN
R4
182k
VCC
L1
1.5
μ
H
16
1
2
15
6
7
8
9
10
11
12
13
14
3
4
5
VIN
VIN
VIN
EN
VSNS
COMP
RT/CLK
SS
PH
PH
PH
BOOT
PWRGD
GND
GND
AGND
VFB
R5
150k 1%
R6
43k 1%
C6
100 nF
PWRGD
EP
17
R2
80.6k
C7
10 nF
R3
10k
C4
10 nF
C5
NM
VFB
C2
100 nF
C3
33 pF
C1
470
μ
F
+
Figure 5: Reference Design of Power Supply
In order to avoid damages to the internal flash, please do not switch off the power supply directly when
the module is working. It is suggested that the power supply be cut off after pulling down the
FULL_CARD_POWER_OFF# pin for about 100 ms.
NOTE