Sunsea AIoT SimCom SIM8918EA User manual
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
2 / 53
GENERALNOTES
SIMCOM OFFERS THIS INFORMATION AS A SERVICE TO ITS CUSTOMERS, TO SUPPORT
APPLICATION AND ENGINEERING EFFORTS THAT USE THE PRODUCTS DESIGNED BY SIMCOM.
THE INFORMATION PROVIDED IS BASED UPON REQUIREMENTS SPECIFICALLY PROVIDED TO
SIMCOM BY THE CUSTOMERS. SIMCOM HAS NOT UNDERTAKEN ANY INDEPENDENT SEARCH
FOR ADDITIONAL RELEVANT INFORMATION, INCLUDING ANY INFORMATION THAT MAY BE IN THE
CUSTOMER’S POSSESSION. FURTHERMORE, SYSTEM VALIDATION OF THIS PRODUCT
DESIGNED BY SIMCOM WITHIN A LARGER ELECTRONIC SYSTEM REMAINS THE RESPONSIBILITY
OF THE CUSTOMER OR THE CUSTOMER’S SYSTEM INTEGRATOR. ALL SPECIFICATIONS
SUPPLIED HEREIN ARE SUBJECT TO CHANGE.
COPYRIGHT
THIS DOCUMENT CONTAINS PROPRIETARY TECHNICAL INFORMATION WHICH IS THE PROPERTY
OF SIMCOM WIRELESS SOLUTIONS LIMITED COPYING, TO OTHERS AND USING THIS DOCUMENT,
ARE FORBIDDEN WITHOUT EXPRESS AUTHORITY BY SIMCOM. OFFENDERS ARE LIABLE TO THE
PAYMENT OF INDEMNIFICATIONS. ALL RIGHTS RESERVED BY SIMCOM IN THE PROPRIETARY
TECHNICAL INFORMATION ，INCLUDING BUT NOT LIMITED TO REGISTRATION GRANTING OF A
PATENT , A UTILITY MODEL OR DESIGN. ALL SPECIFICATION SUPPLIED HEREIN ARE SUBJECT TO
CHANGE WITHOUT NOTICE AT ANY TIME.
SIMCom Wireless Solutions Limited
SIMCom Headquarters Building, Building 3, No. 289 Linhong Road, Changning District, Shanghai P.R.
China
Tel: +86 21 31575100
Email:[email protected]
For more information, please visit:
https://www.simcom.com/module/smart_modules.html
For technical support, or to report documentation errors, please visit:
https://www.simcom.com/ask/oremailto:support@simcom.com
Copyright © 2021 SIMCom Wireless Solutions LimitedAll Rights Reserved.
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
3 / 53
1 Introduction
1.1Product Outline
SIM8918x series module is a 4G Android smart module developing by the platform of Qualcomm
QCM2290，a 64-bit applications processor with Arm Cortex-A53 quad-cores at 2.0GHz with 512KB L2
cache. SIM8918x series module has abundant multi-media functions, including the 1080P@30 fps video
codec, the HD+ 720*1680@60Hz displaying screen, two MIPI-CSI cameras, and the multi-channel analog-
and digital-audio input and output. SIM8918x series module supports multiple communication modes,
including the GSM/GPRS/EDGE, the WCDMA/HSPA+, the LTE-FDD, and the LTE-TDD. It also supports
the WiFi 802.11 a/b/g/n/ac, and the BT4.x short range communication. For the satellite positioning system,
SIM8918x series module supports the GPS, the GLONASS, the BEIDOU, and the Galileo. In conclusion,
SIM8918x series module is a highly integrated product, which is widely applying to intelligent terminal
devices in the field of the Internet of Things (IOT).
ModelName:SIM8918EA,SIM8918E
Product Name: LTE Wireless Data Module
Brand name: SIMCom
1.2Functional Overview
Feature
Description
Processor
64-bit Arm Cortex-A53
Quad-cores at 2.0GHz with 512KB L2 cache
Memory
1804MHz clock （2*16-bit）BUS LPDDR4x SDRAM design
Built-in eMMC 5.1 Flash,
16GB eMMC + 2GB LPDDR4x
Or 32GB eMMC+3GB LPDDR4x (option)
Or 8GB eMMC + 1GB LPDDR3
(option)
SD
SDC2 external interface supports SD3.0 TF card (Maximum 256G), support hot
plugdetection
OperationSystem
Support Android 12/13
SystemUpgrade
Upgrade via USB interface, support forced download
Power Supply
Power Domain: 3.4V~4.4V, support single-cell lithium battery power supply.
Charge
Internal charger, supports high charging current up to 1.8A
Display
One 4-Lane MIPI_DSI interface, the highest resolution is 720*1680, HD+.
Camera
Two CSI MIPI configurable 4/4 or 4/2/1
D-PHY：2.5Gbps /channel
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
4 / 53
C-PHY：~10Gbps（3.42Gbps/channel）
Single ISP: 13 MP 30 ZSL; dual ISP: 25 MP 30 ZSL
Real time sensor input resolution: 25MP or 13MP+13MP
Video Codec
Encode: 1080p30 8-bit HEVC(H.265),H.264
Decode: 1080p30 8-bit H.264, HEVC(H.265),VP9
Concurrency: 1080p30 decode + 720p 30 encode
Audio
1-Channel Digital Audio Interface I2S: Support Master- and Salve-Mode
3-Channel Analog Audio Input
Master Microphone MIC1: Differential Input
Headphone Microphone MIC2: Single-end Input
De-noise Microphone MIC3: Differential Input
4-Channel Digital Microphone Input
3-Channel Analog Audio Output
Headphone: Class AB Amplifier Stereo Output
Receiver: Class AB Amplifier Differential Output
Lineout: Class AB Amplifier Differential Output
Audio Codec
MP3, AAC, He-AAC v1, v2, FLAC,APE, ALAC, AIFF
VoiceCodec
EVS, EVRC, EVRC-B, and EVRC-WB
G.711 and G.729A/AB
GSM-FR, GSM-EFR, and GSM-HR
AMR-NB and AMR-WB
USB
Support USB 3.1, support USB2.0
Support USB Type-C Interface
SupportOTG
USB_VBUS OTG Mode 5V Power Output (500mA Typical)
UART
Support up to 3 Serial Ports
A 2-Wire Serial Port for Debug
Two 4-Wrie Serial Ports support hardware flow control, High-speed up to 4Mbps.
I2C
Support up to seven I2C for touch screen, camera, sensor and other peripherals
SPI
Support up to 2*SPI interfaces, support master mode, the highest rate 50MHz
UIM Card
Support Dual Card Dual Standby: 1.8V/3.0V Dual Voltage
Power Level
Class 4 (33dBm±2dB) for EGSM850
Class 4 (33dBm±2dB) for EGSM900
Class 1 (30dBm±2dB) for DCS1800
Class 1 (30dBm±2dB) for PCS1900
Class E2 (27dBm±3dB) for EGSM850 8-PSK
Class E2 (27dBm±3dB) for EGSM900 8-PSK
Class E2 (26dBm±3dB) for DCS1800 8-PSK
Class E2 (26dBm±3dB) for PCS1900 8-PSK
Class 3 (24dBm+1/-3dB) for WCDMA bands
Class 3 (23dBm±2dB) for LTE-FDD bands
Class 3 (23dBm±2dB) for LTE-TDD bands
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
5 / 53
LTE Features
Support 3GPP R10 CAT4 FDD and TDD
Support 1.4 to 20 MHz RF Bandwidth
Support Downstream 2x2 MIMO
FDD: the maximum 150Mbps(DL) / the maximum 50Mbps(UL)
TDD: the maximum 150Mbps(DL) / the maximum 35Mbps(UL)
UMTS Features
Support3GPPR8DC-HSDPA/HSPA+/HSDPA/HSUPA/WCDMA
Support 16-QAM, 64-QAM and QPSK modulation
DC-HSDPA:maximum42Mbps(DL)
HSUPA:maximum5.76Mbps(UL)
WCDMA: maximum 384Kbps(DL) / maximum 384bps(UL)
GSM Features
R99:
CSD: 9.6Kbps, 14.4Kbps
GPRS: Support GPRS Multi-Slot Level 33(Default 33)
Coding format: CS-1, CS-2, CS-3, and CS-4
Maximum 85.6Kbps(UL) / Maximum 107Kbps(DL)
EDGE: Support EDGE Multi-Slot Level 33(Default 33)
Support GMSK and 8-PSK modulation and coding Methods
Downlink Coding Format: CS 1-4 and MCS 1-9
Uplink Coding Format: CS 1-4 and MCS 1-9
The maximum 236.8Kbps(UL) / The maximum 296Kbps(DL)
WLAN Features
2.4G/5G Dual Frequency Range, Support 802.11a/b/g/n/ac, Maximum 433Mbps
Supportthe Wake-on-WLAN.
Support the WAPI SMS4 hardware encryption.
Support the AP mode and the STATION mode.
Support the WIFI Direct.
Support the 2.4G MCS 0~8 for HT20 and VHT20.
Support the 2.4G MCS 0~7 for HT40 and VHT40.
Support the 5G MCS 0~7 for HT20, HT40
Support the 5G MCS 0~8 for VHT20.
Support the 5G MCS 0~9 for VHT40 and VHT80.
BT Features
BT2.1+EDR /3.0 /4.2 LE/5.x
Satellite
Positioning
GPS/GLONASS /BEIDOU/Galileo
Temperature
Operation Temperature: -35℃~ +75℃
Extend Operation Temperature: -40℃~ +85℃［1］
Storage Temperature: -40℃~ +90℃
Physical Size
Size: 40.5(±0.2)*40.5(±0.2)*2.85(±0.2)mm
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
6 / 53
BT/WIFI
Baseband
Tx Module
4G/3G/2G MODEM
Core
MODEM/Voice
Processor
GNSS
Baseband
Memory
Support
Codec Digital
720*1680 LCD
REAL Cam(25MP)
Front Cam(25MP)
4-Lane DSI0
4-Lane CSI0
4-Lane CSI1
FrontEnd
RFFE1
MAIN
RFFE2
AP
Type-C USB
UIM Card1
UIM Card2
SD Card
TP/Sensor/others
USB HS/USB_SS0+SS1
UIM1
UIM2
SDC2
I2C/I3C/SPI/UART
GPIOs
4 SMPS output
Modem
TX_DACI/Q
PRX_CA1I/Q
PA
DRX_CA1 I/Q
GPS_ADCI/Q
Transceiver
RFFE5
DRX
Switch
VPH_PWR
LC_networks
Input/Output
Power
Management
LC_networks
VRTC
Poweronsingals
GPIO
24 VREG output
IC-level interface
SPMI BUS
LNA
GNSS
Haptics output
User
interfaces
38.4M XO
Baseband
Analog inputs
Clocks
General
houseke
eping
USB_IN
VPH_PWR
Battery
WLAN RX I/Q
WLANTXI/Q
WLANCNTRLclk/data
WLAN-BTcoexclk/data
SSCdata2-wire
BT/WiFi
Charger
WCN
Pon singals
RF_CLK38.4M
Sleep_CLK 32K
GPIOs
IC-level interface
BTcontrol/data4-wire
BTaudioclk/data
WLAN_CLK 38.4M
38.4M XO
Flashoutput
Charge LED
Analog Micphone
Earphone
Headset
LINEOUT
Userinter
faces
EBI0/EBI1
Audio
Codec
eMMC flash +
LPDDR4x
SDC1
2 Package Information
2.1Hardware Block Diagram
64-bit Arm Cortex-
A53
CameraISP/
VFE/JpegHW
Display Processor
Video
Graphics
Peripherals
Figure 1: Module Block Diagram
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
7 / 53
283
GND
286
GND
*
108
SD
_V
DD 38
SD
_
C
L
K
39
SD
_
C
M
D
40
SD
_
DATA0 41
146
145
144
143
142
141
140
139
138
137
136
135
134
133
132
131
130
129
128
127
126
125
124
123
122
121
120
119
118
117
116
115
114
113
112
42
43
SD
_
DATA3 44
SD
_
D
E
T
US
B_B
OOT
45
46
T
P_I
2C
_
SC
L
47
T
P_I
2C
_
SDA
L
CD
_R
ST
L
CD
_
T
E
G
N
D
DS
I_
C
L
K
_N
DS
I_
C
L
K
_P
48
49
50
51
52
53
54
55
DS
I_LN
1
_N
56
DS
I_LN
1
_P
57
DS
I_LN
2
_N
DS
I_LN
2
_P
DS
I_LN
3
_N
59
60
61
62
63
CS
I
1
_
C
L
K
_P
CS
I
1
_LN
0
_N
64
65
66
67
68
69
70
71
72
73
2.2Pin Assignment Overview
VBAT 1
VBAT 2
186
185
184
183
182
*
181
* *
180 179 178
177
*
*
110
109
GPIO_36
GPIO_34
SDC2
GND 3
MIC1_P 4
CBL_PWR_N
BAT_ID
VPH_PWR
BAT_M
GPIO_86
NFC_CLK
FLASH_LED RESERVED RESERVED GPIO_112
*
*
107
GPIO_33
GPIO_35
USB
MIC1_N 5
MIC2_P 6
147
MIC_BIAS1
187
GND
222
GND
221
GND
220
GND
219
GND
218
GND
217
GND
216
GND
215
GND
214
GND
176
GND 106
*105
GPIO_56
GPIO_99
UART
GND 7
EAR_P 8
EAR_N
148
MIC3_P
188
GND
223
GND
250
GND
249
USB_CC1
248
GND
247
GND
246
USB_CC2
245
GND
244
GND
213
GND
175
RESERVED
*
104 GPIO_102
*
103 GPIO_103
102 GPIO_105
USIM
9
LINEOUT_P
*
101
GPIO_104
AUDIO
10
LINEOUT_M
149
189
224
251
270
269
268
267
266
243
212
*
174
GPIO_55
11
GND
USB_DM 12
USB_DP 13
MIC3_N
GND GND GND
USB_SS1_
RX_M
GND GND
GPIO_111
GND GND GND
RESERVED
100
* 99
* 98
GPIO_32
GPIO_107
GPIO_31
GPIO
Antenna
GND 14
150
190
USB_SS2_
225
252
USB_SS1_
265
242
211
173
* 97 VOL_DOWN
RESERVED
USIM2_DET
USIM2_RST
15
16
17 *
TX_P
151
USB_SS2_
GND
191
GND
RESET_N
226
GND
RX_P
253
USB_SS1
GPIO_98
264
GPIO_100
RESERVED
241
GND
GND
210
GND
GRFC_13
172
GND
96
* 95
94
VOL_UP
DEBUG_TXD TP
DEBUG_RXD
USIM2_CLK
USIM2_DATA
USIM2_VDD
18
19
20 *
TX_M
152
192
227
_TX_M
254
SIM8918
284
263
240
209
171
*93
*
92
91
SENSOR_I2C_SDA
SENSOR_I2C_SCL
GPIO_106
GND
LCM
Camera
USIM1_DET
USIM1_RST
21
22 *
USB_SS2_
RX_P
USB_SS2_RX
_M
GND
USB_SS1_
TX_P
GND
285
GND
RESERVED
GND GND GND * 90
89
GND
ANT_MAIN
Others
USIM1_CLK 23
USIM1_DATA 24
USIM1_VDD 25
GND
153
*
193
UART1_RXD RESERVED
228
GND
255
GND
262
GRFC_15
239
*
GPIO_101
208
GND
170
LPI_GPIO_
26
88 GND
87 GND
86 CAM0_I2C_SDA
RESERVED
VIB_DRV_P 26
PWM 27
154
*
UART1_TXD
194
GNSS_L
NA_EN
229
GND
256
GND
257
RESERVED
258
GND
259
GND
260
GRFC_14
261
GND
238
GND
207
GND
169
LPI_GPIO_
25
85 CAM0_I2C_SCL
84 CAM1_PWDN
83
POWER
TP_INT_N 28
TP_RST_N 29
SD_LDO4 30
*
155
MIC_BIAS3
195
CHG_LED
230
GND
231
GND
232
RESERVED
233
GND
234
GND
235
GND
236
GND
237
GND
206
GND
168
SNSR_
I3C_SCL
82
* 81
CAM1_RST
CAM0_PWDN
CAM0_RST
GND
GPIO_28 31
UART0_TXD 32
UART0_RXD 33
*
156 196
197
198
199
200
201
PM_GPIO_7
202
GND
203
GND
204
GND
205
CAM1_I2
167
SNSR_
* 80
* 79
78
GND
ANT-WIFI/BT
GND
UART0_CTS 34
UART0_RTS 35
*
36 *
37
VREG_17A_3V0
CSI0_CLK_P
157
CSI0_CLK_N
CSI0_LN0_P
158
CSI0_LN0_N
CSI0_LN1_P
159
CSI0_LN1_N
CSI0_LN2_P
160
CSI0_LN2_N
CSI0_LN3_P
161
CSI0_LN3_N
162
GND
163
CAM2_PWDN
164
*
CAM2_RST
165
*
CAM_
MCLK2
C_SDA
166
CAM1_I2
C_SCL
I3C_SDA
77 CAM_MCLK1
76 CAM_MCLK0
75
74
* *
* *
Note: GPIOs with * can
be used to wake up the
module.
Figure 2: PinAssignment Overview
271
GND
282
GND
281
GND
280
GND
272
GND
279
GND
273
GND
278
GND
274
GND
275
GND
276
GND
277
GND
VB
AT
VB
AT
G
N
D
G
N
D
US
B_VB
US
US
B_VB
US
G
N
D
HS
_
D
E
T
H
P
H
_L
H
P
H
_
G
N
D
H
P
H
_R
G
N
D
B
AT
_
TH
ERM
B
AT
_P
G
N
D
A
N
T
_
D
R
X
G
N
D
V
DD
_
2
V
8
ADC
PM_
G
PI
O
_
8
VR
TC
L
DO
_I
O
V
DD
PM_
G
PI
O
_
3
G
PI
O
_
60
G
N
D
A
N
T
_
G
N
SS
G
N
D
G
PI
O
_
15
G
PI
O
_
14
G
PI
O
_
17
G
PI
O
_
16
PM_
G
PI
O
_
4
PWR_
K
EY_N
G
PI
O
_
58
G
PI
O
_
57
SD
_
DATA1
SD
_
DATA2
DS
I_LN
0
_N
DS
I_LN
0
_P
58
DS
I_LN
3
_P
GND
CS
I
1
_
C
L
K
_N
CS
I
1
_LN
0
_P
CS
I
1
_LN
1
_N
CS
I
1
_LN
1
_P
GND
CS
I
1
_LN
3
_N
CS
I
1
_LN
3
_P
CS
I
1
_LN
2
_N
CS
I
1
_LN
2
_P
111
VRE
G
_
15A
_
1
V
8
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
10 / 53
+
GND
3 InterfaceApplications
3.1Power Supply
The SIM8918x module operating power (VBAT) is 3.4V to 4.4V, and the typical voltage is 3.9V. The
instantaneous peak current of the SIM8918x module could reach 3A. So, to enable the module is running
smoothly, the power supply should be able to provide the peak current up to 3A. If the power supply is
designed improperly, there would be a large voltage drop on the VBAT. The shutdown voltage of the
SIM8918x module is 3.2V. If the voltage drop on the VBAT is lower than 3.2V, the module would power off.
3.1.1
Pin Overview
SIM8918x series module supports a single lithium battery power supply (4.2V or 4.35V battery cell). It also
supports the other types of batteries. But the maximum voltage could not exceed the maximum allowance
voltage of the module. Otherwise, the module would be burned. In terms of the non-battery power supply
applications, the module would power by an LDO when the DC input is up to 5V. The reference design is
showing in Figure 3.
DC INPUT
U101 MIC29302
VBAT
C101
+
C102
2 Vin
1
On/Off
Vout 4
FB 5
R101
100uF
1uF
100K
C103
PWR_CTRL 3
330uF
C104
100nF
R103
470R
R102
43K
Figure 5: LDO Power Supply Reference Design
Highly recommend selecting arelative high efficiency switching power supply for hardware design when the
difference between the input (DC Input) and the output (VBAT) is too large.
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
11 / 53
GND
DC INPUT
U101 LM2596-ADJ
L101 FB101
VBAT
1 Vin Vout 2
C101
+
C102
5
100uH
270R@100MHz
100uF
1uF
PWR_CTRL
On/Off
3
FB 4
D102 C103
+
330uF
MBR360
C104
100nF
R101
2.2K
R102
1K
Figure 6: DC-DC Power Supply Reference Design
Figure 7: DC-DC Power Supply Reference Design
C101 and C102 are two Low-ESR 100uF tantalum capacitors. C103 is a 1uF to 10uF ceramic capacitor.
The function of C104 and C105 is to decrease the high frequency interference. D101 is a 5V/1600W
transient voltage suppression diode, preventing the chip from being damaged by surge. For PCB wiring, the
capacitors and the diodes should be close to the VBAT Pin as far as possible, and the VBAT wiring should
1.
Highly recommend disconnect the VBAT power supply to power off the module when the module is
running abnormally.After that, restart the module by powering.
2.
The module supports the charging function. There is a need to turn off the charging function in the
software patch when the customers are using the power supply without the charging function. Or
connect Schottky diodes in series on the VBAT channel to prevent the current anti-flowing into the
chip.
NOTE
3.1.2
Power Supply Stability Design
Highly recommend place bypass capacitors and voltage stabilizing components near the VBAT Pin to
enhance the stability of the power supply. The reference design is showing in the Figure 5.
VBAT
VBAT
SIM8918x
Module
GND
C105 C104 C103
C102
C101
D101
10pF
33pF
10uF
100uF
100uF
5V
1600W
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
12 / 53
be as short as possible with the width at least 3mm.
Vendor
Manufacture Number
Power(Watts)
Package
1
PRISEMI
PTVSHC3N4V5B
2800W
DFN2020-3L
2
PRISEMI
PTVSHC2EN5VU
1600W
DFN1610-2L
3.2Power On & Power Off
The on-off of the SIM8918x series module has two status, including the normal on-off and the abnormal on
-off. In terms of the high- and low-pressure, and the high- and low-temperature, it should be working within
the maximum power domain when running the module. Otherwise, exceeding the absolute maximumpower
domain would cause permanent damage to the module.
3.2.1
Power On
PWR_KEY_N (114 Pin) defines as the boot-up key when the VBAT is powering on, and triggering
PWR_KEY_N with at least 2s low-level pulse starts the module. KPD_PWR_N Pin has internal pull-up, and
the typical high-level voltage is 1.2V. The reference design is showing as below.
1.8V
R
1K
PWR_KEY_N
PMU
SIM8918x Module
Figure 8: Power On/Off Design with a Key
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
13 / 53
Pulse
Figure 9: Power On/Off Design with an OC Gate
Highly recommend the customers consider the PWR_KEY_N Pin’s electrical characteristics when
designing.The electrical characteristics are showing in following：
Parameters
Description
Minimum
Typical
Maximum
Unit
VIH
High-LevelInputVoltage
0.8
-
-
V
VIL
Low-LevelInput Voltage
-
-
0.6
V
3.2.2
Power On Sequence
Figure shows the power on sequence of the module.
VBAT
PWR_KEY_N
T>50ms
t>2s
VREG_L15A_1P8
VREG_L17A_3P0
LDO_2V8
LDO_IOVDD
128ms
SW control
SW control
Figure 10: Power On/Off Design with an OC Gate
1.8V
R
PWR_KEY_N
1K
4.7K
PMU
47K
SIM8918xmodule
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
14 / 53
3.2.3
Power Off
3.3VRTC
The VRTC is a standby power supply, connecting with a button battery or a large capacitor. VRTC would
help to maintain the RTC timing when the VBAT is powering off. VRTC would also work as charging the
button battery or a large capacitor when the VBAT is powering on.
⚫
If the RTC fails, the RTC clock could be synchronized by connecting the data when the module is
powering on.
⚫
Please refer to theTable 10 for VRTC characteristics.
⚫
The input power domain for the VRTC voltage supply is 2.0V to 3.25V. The typical voltage is 3.0V.
1.
The hardware design should cove the function of powering off the module. It is forbidden to run the
module when powering off or restarting. Forced powering off the module adopts only when the
module is running abnormally.
2.
Highly recommend adding a low-cost MCU to control the PWR_KEY_N. Not only for the normal
powering on and powering off but also for the watchdog function to protect the operation system.
3.
Do not cut off the VBAT power supply directly when the module is running smoothly. It is to protect
the internal flash memory.
4.
Highly recommend to power off the module by the PWR_KEY_N Pin or the AT command before
disconnecting the VBAT power supply.
Pull down the PWR_KEY_N Pin with at least 1s to power off the module. There is a pop up prompt window
confirming the action of shutting down the device when the module detects the control instructions. Apart
from that, pulling down the PWR_KEY_N Pin with over 8s would be forced to restart the module.
Powering on and powering off are using the same pin, and they have the same reference design.
NOTE
Highly recommend pulling down the PWR_KEY_N Pin when booting up the VBAT voltage at 3.8V
stabilizing for at least 50ms. Do not pull down the PWR_KEY_N Pin all the time.
NOTE
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
15 / 53
The average current consumption is 10uA when disconnecting the VBAT and connecting the RTC
only.
⚫
When powering on via the VBAT, the RTC working error is 50ppm. Switching the power supply
mode of the VRTC Pin cause the RTC working error is 200ppm.
⚫
Highly recommend the ESR of the button battery is less than 2K when connecting an external
rechargeable button battery. Highly recommend to pick SEIKO’s MS621FE FL11E.
⚫
Highly recommend the ESR of the capacitor is 100uF when connecting an external large capacitor.
The reference designs for VRTC are showing below.
⚫
External Capacitor Power Supply for RTC
Large
Capacitor
VRTC
Module
RTC
Circuit
Figure 11: External Capacitor Power Supply for RTC
⚫
Non Rechargeable Battery Power Supply for RTC
Non
Rechargeable
Battery
VRTC
Module
RTC
Circuit
Figure 12: Non Rechargeable Battery Power Supply for RTC
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
16 / 53
⚫
Rechargeable Battery Power Supply for RTC
Rechargeable
Battery
VRTC
Module
RTC
Circuit
Figure 13: Rechargeable Battery Power Supply for RTC
The typical voltage of the VRTC is 3.0V. And the average current consumption is 20uAwhen disconnecting
the VBAT and connecting the RTC only. The VRTC characteristics are showing in Table 13.
Parameters
Description
Minimum
Typical
Maximum
Unit
VRTC-IN
VRTC Input Voltage
2.0
3.0
3.25
V
T- series resistance
Standby Battery connecting
in series resistor
800
-
2000
Ω
IRTC-IN
VRTC Current Consumption
（VBAT=0V）
-
10
-
uA
Accuracy
Power ON
Power ON
-
-
24
ppm
Power OFF
Poweroff（VBATon）
-
-
50
ppm
Poweron（VBAT=0）
-
-
200
ppm
1，If the VBAT is connecting an external non-removable rechargeable battery, float the VRTC Pin.
Also, the software should be modified to turn off the VRTC charging instructions.
2，If the VBAT can be turn off and external Coin-cell battery doesn’t use，it is recommended that a
minimal 47uF capacitor add on VRTC pin.
NOTE
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
17 / 53
3.4Power Output
SIM8918x series module has 18 power outputs in total, which are suitable for a wide range of external
interfaces and peripherals. Highly recommend a capacitor of 33pF and a capacitor of 10pF parallel
connection to the ground, which could prevent high-frequency interference effectively.
Power Name
PIN
Num
Output
Voltage(V)
Rated
Current (mA)
Default
On
Description
VPH_PWR
184
3.4~4.4
2000
ON
Generated by either the
charger or the battery
VREG_L15A_1P8
111
1.8
300
ON
External Power and
External GPIO pull up
and the 1.8V power
levelconversion
USIM1_VDD
26
1.8/2.95
150
Off
SIM Card1 Power
USIM2_VDD
21
1.8/2.95
150
Off
SIM Card2 Power
SD_LDO4
32
3.0
22
Off
SD Card pull-up Power
SD_VDD
38
3.0
800
Off
SD Card Power
VREG_L17A_3P0
129
3.0
200
Off
Power for sensor
LDO_IOVDD
125
1.8
300
ON
LCM DVDD or camera
IOVDD
VDD_2V8
129
2.8
300
ON
CameraAVDD
MIC_BIAS1
147
1.6-2.85V
6
Off
MicrophoneBias
MIC_BIAS3
155
1.8
6
Off
MicrophoneBias
3.5Charging and Battery Management
SIM8918x series module supports high charging current up to 1.8 A (100 mA step size).Supports trickle
charge，pre-charge，constantcurrentcharging，and constant voltage charging.The moduleintegratesthe
internal charging temperature rising control function. Decreasing the charging voltage and the charging
current happens automatically when the temperature is too high.
SIM8918x series module could charge the battery. It supports several charging modes, including the trickle
charging mode, the pre-charging mode, the constant current chargingmode, and theother charging modes.
⚫
TheTrickle Charging Mode:
The system is running into the trickle charging mode when the voltage of the battery is lower than
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
18 / 53
2.1V. In this case, a charging current of 100mA(typical) is applied.
⚫
The Pre-charging Mode:
The system is running into the pre-charging mode when the voltage of the battery is between 2.1V
and 3.0V (The cut-off voltage is programmable between 2.4V and 3.0V, Default 3.0V). The charging
current is about 300mA (The current is programmable between 100mA and 450mA, Default
300mA).
⚫
The Constant Current Charging Mode:
The system is running into the constant current charging mode when the voltage of the battery is
between the cut-off voltage of the pre-charging mode and 4.2V (The voltage is programmable
between 3.6V and 4.2V, Default 4.2V). The charging current is programmable between 0mA and
1800mA(The Default USB charging current is setting at 500mAin the software configuration).
⚫
The Constant Voltage Charging Mode:
The system is running into the constant voltage charging mode when the voltage of the battery is
reaching at the predefined float voltage. The charging status would stop when the charging current
is reaching at setting current.
PIN Name
PIN Num
I/O
Description
Note
VBAT
1
2
145
146
PI/
PO
Module Power Input,
BatteryChargeOutput
BAT_ID
185
AI
BatteryDetection
Don’t be float.
Highly recommend an external
100KR resistor connecting to
the ground when no battery ID.
BAT_THERM
134
AI
Battery Thermal Detection
Don’t be float.
Connect to the battery NTC
Resistor,
Highly recommend an external
100KR resistor connecting to
the ground when no battery.
BAT_P
133
AI
Battery Voltage Detection +
Connect to VBAT close to
battery.
BAT_M
183
AI
Battery Voltage Detection -
Connect to
GND close to
battery.
SIM8918x series module has the function of battery detection. Generally, there is a BAT_ID Pin in the
battery. Highly recommend an external 100KR resistor (R2) connecting to the ground when the battery has
no BAT_ID.Avoid float.
SIM8918x series module has the function of battery temperature detection. This function requires an
integrated thermistor in the battery (Recommend a 100KR ± 1% NTC Resistor). And the NTC resistor
needs to connect to the BAT_THERM Pin. The module would charge fail when floating the BAT_THERM
pin.
SIM8918EA_SIM8918NA_User Manual
www.simcom.com
19 / 53
SIM8918x series module has the function of battery’s fuel gauge. It estimates the real-time power of the
battery accurately. Not only protect the battery and prevent the over dis-charge but also help the users to
estimate the entertainment time and save the important data. For different types of batteries, modifying the
software settings enables the designated battery working properly.
The BAT_P Pin and the BAT _M Pin must be connected whether the module is powering on by a battery or
a stable power supply. The module would not work well if floating these two pins. These two pins are for
battery voltage detection. Differential pair routing and stereo ground plane are needed.
SIM8918x MODULE BATTERY
CONNECTOR
BAT_P
BAT_M
VBAT
BAT_ID
BAT_THERM
GND
VBATT
BATT_ID
BATT_THERM
GND
NTC
R2 100K R3 100K
Figure 14: Battery Connection Reference Design
3.6USB Interface
3.6.1
Micro-USB Interface and Type-C Interface
SIM8918x series module supports a USB interface, complying with USB 3.1/2.0 protocol and
supporting USB OTG. The highest speed for the USB3.1 is up to 10Gbps, and for the USB 2.0 is up to
480Mbps. It is downward compatible with full speed (12Mbps) mode. USB_HS interface supports the
function of the AT command transmission, of the data transmission, of the software debugging, and of the
softwareupgrading.
SIM8918x series module recommends Type-C USB. When used Micro-USB interface，the CC1 pin
need to connect to the Micro USB connector‘s USB_ID，and 10K pull-up resistor to VBUS.
This manual suits for next models
1
Table of contents
Other Sunsea AIoT Computer Hardware manuals
