Product Info

5G Module Series
RM502Q-GL Hardware Design
RM502Q-GL_Hardware_Design 23 / 77
The following figure shows a reference design for +5 V input power source based on an 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 μF
C11
10 pF
C10
33 pF
C9
100 nF
+
R1
205k
U1
Q1
NPN
R8
47k
R7
4.7k
PWR_EN
R4
182k
PWR_OUT
L1
1.5 μH
TPS54319
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
330k 1%
R6
100k 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 μF
+
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 can be cut off after the module is powered off
by pulling down the FULL_CARD_POWER_OFF# pin for more than 10 s.
3.4. Turn on and off Scenarios
3.4.1. Turn on the Module
FULL_CARD_POWER_OFF# asynchronous signal is an Active Low input that is used to turn off the
entire module. When the input signal is asserted high ( ≥ 1.19 V) the Module will be enabled. When the
input signal is driven low signal ( ≤ 0.2 V) or Tri-stated, it will force the module to shut down.
This input signal is 3.3 V tolerant and can be driven by either 1.8 V or 3.3 V GPIO. Also, it has internally
pulled down with a 100 kΩ resistor.
The following table shows the definition of FULL_CARD_POWER_OFF#.
.
Table 6: Definition of FULL_CARD_POWER_OFF# Pin
Pin No.
Pin Name
Description
DC Characteristics
Comment
6
FULL_CARD_
POWER_
OFF#
Turn on/off of the module.
When it is at low level, the module
is powered off.
V
IH(max)
= 4.4 V
V
IH(min)
= 1.19 V
V
IL(max)
= 0.2 V
Internally pulled
down with a
100 kΩ resistor
NOTE