Reference Design For Power Supply - Quectel RM500Q-AE Manual

VCC
D1
5.1 V
3.3.2.3.4.2.

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 is capable of providing a sufficient current of at least 3 A. If the voltage
drop between the input and output is not too high, it is suggested that an LDO is used to supply 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 as the power supply.
The following figure shows a reference design for +5 V input power source based on the DC-DC
TPS54319. The typical output of the power supply is about 3.7 V and the maximum load current is 3 A.
PWR_IN
+
D1
C1 C2 C3
470 μF
TVS 100 nF 33 pF
R7
4.7k
PWR_EN
R8
47k
NOTE
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 can be cut off after the module is powered off by
pulling down the FULL_CARD_POWER_OFF# pin for more than 10 ss.
RM500Q-AE&RM502Q-AE_Hardware_Design
+
C1
C2 C3
100 μF
1 μF
100 nF
Figure 4: Reference Circuit of VCC Pins
VIN
R1 VIN
VIN
205k
EN
R2
VFB VSNS
COMP
80.6k
RT/CLK
SS
R3 R4
10k 182k
Q1
NPN
C4
C5 C7
10 nF 10 nF
NM
Figure 5: Reference Design of Power Supply
RM500Q-AE&RM502Q-AE Hardware Design
2, 4, 70, 72, 74
VCC
C4 C5
33 pF 10 pF
3, 5, 11, 27,
33, 39, 45,
GND
51, 57, 71,
73
L1
U1
μ
1.5 H
TPS54319
PH
PH
C6
PH
100 nF
BOOT
PWRGD
GND
GND
AGND
EP
17
VFB
5G Module Series
Module
PMU
PWR_OUT
+
C8 C11
C9 C10
220 μF
100 nF 33 pF 10 pF
R5
330k 1%
R6
100k 1%
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