MEIG SLM550 Guide

MeiG_SLM550_Hardware Design Manual
MeiG Smart Technology Co., Ltd 1/89
MeiG SLM550
Hardware Design Manual
Released Date: 2022/07/20
Version Number: V1.02

MeiG_SLM550_Hardware Design Manual
MeiG Smart Technology Co., Ltd
Important Notice
Copyright Notice
All rights reserved. MeiG Smart Technology Co., Ltd
This manual and all its contents are owned by MeiG Smart Technology Co., Ltd and
protected by Chinese laws and relevant copyright laws in applicable international
conventions. Without the written authorization of MeiG Smart Technology Co., Ltd, no one
may copy, disseminate, distribute, modify or use part or all of this manual in any form, and
the offenders will be held responsible according to law.
Statement of No Guarantee
MeiG Smart Technology Co., Ltd makes no representations or guarantees, either express
or implied, for any contents in this document, and assumes no responsibility for the
merchantability and fitness for a particular purpose or any indirect, extraordinary or
consequential losses.
Confidentiality Claim
The information contained in this document (including any annexes) is confidential. The
recipient understands that the document obtained by him is confidential and shall not be
used for any purpose other than the stated purpose, and he shall not disclose this
document to any third party.
Disclaimer
The company assumes no responsibility for property damage or personal injury caused by
customers’ improper operation. Customers are requested to develop corresponding
products according to the technical specifications and reference designs in the manual.
Before the disclaimer, the company has the right to change the contents of this manual
according to the needs of technological development, and the version is subject to change
without further notice.
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Revision History
Revision Date Description
V1.00 2021-04-01 First edition
V1.01 2021-05-24
1. Module pin distribution diagram
2. The capacity of TF card is modified to support 256GB at most.
3. Update the pin characteristics table
V1.02 2022-07-20
1. Add multiplexing function Table 43.
2. Update microphone receiving circuit Figure 26.
3. BAT_THERM Pull-down resistor correct to 47K
4. Update Table 6.
5. Update Figure 1, Figure 2, Figure 3.
6. MIPI impedance requirements 85 +/-15Ω.
7. Add FCC Statement.

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SLM550 Hardware Design Guide_V1.02

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Foreword
Thank you for using the SLM550 module from Meg Smart. This product can provide data
communication services. Please read the user manual carefully before use, you will appreciate its
perfect function and simple operation method.
The company does not assume responsibility for property damage or personal injury caused by
improper operation of the user. Users are requested to develop the corresponding products according
to the technical specifications and reference designs in the manual. Also pay attention to the general
safety issues that mobile products should focus on.
Before the announcement, the company has the right to modify the contents of this manual according to
the needs of technological development.

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FCC Statement
Changes or modifications not expressly approved by the party responsible for compliance could void
the user's authority to operate the equipment.
This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designtion. This equipment generates uses and
can radiate radio frequency energy and, if not installed and used in accordance with the instructions,
may cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful interference
to radio or television reception, which can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one or more of the following measures:
-- Reorient or relocate the receiving antenna.
-- Increase the separation between the equipment and receiver.
-- Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
-- Consult the dealer or an experienced radio/TV technician for help
This device complies with part 15 of the FCC rules. Opject to the following two conditions (1)this device
may not cause harmful interference, and (2) this device must accept any interference received, including
interference that may cause undesired operation.
FCC standards:
Antenna Gain:BT/2.4G Wifi 2.2dBi, 5G wifi 2.52dBi, GSM/GPRS/EGPRS 850: 3.52dBi, GSM/GPRS/
EGPRS 1900: 3.58dBi, WCDMA Band V: 3.52dBi, WCDMA Band II: 3.58dBi, LTE Band 2: 3.58dBi, LTE
Band 4: 4.00dBi, LTE Band 5: 3.52dBi, LTE Band 7: 5.19dBi, LTE Band 12: 3.65dBi, LTE Band 13:
3.81dBi, LTE Band 17: 3.65dBi, LTE Band 25: 3.58dBi, LTE Band 26-1: 3.52dBi, LTE Band 26-2:
3.52dBi, LTE Band 66: 4.00dBi
RF Exposure Compliance:
This equipment should be installed and operated with a minimum distance of 20cm between the
radiator and any part of your body. This module is installed on the host equipment and requires a
Permissive Class II Change test if the exposure conditions change.
OEM INTEGRATION INSTRUCTIONS:
This device is intended only for OEM integrator under the following conditions:
The module must be installed in the host equipment such that 20 cm is maintained between the antenna
and users, and the transmitter module may not be co-located with any other transmitter. The module
shall be only used with the antenna that has been originally tested and certified with this module. As
long as these 3 conditions above are met, further transmitter test will not be required.
However, the OEM integrator is still responsible for testing their end-product for any additional
compliance requirements required with this module installed. The end-product may need Verification
testing, Declaration of Conformity testing, a Permissive Class II Change or new Certification. Please
involve a FCC certification specialist in order to determine what will be exactly applicable for the end-
product.

In the event that these conditions cannot be met, then the FCC authorization for this module in
combination with the host equipment is no longer considered valid and the FCC ID of the module
cannot be used on the final product. In these circumstances, the OEM integrator will be
responsible for re-evaluating the end product (including the transmitter) and obtaining a separate
FCC authorization. In such cases, please involve a FCC certification specialist in order to
determine if a Permissive Class II Change or new Certification is required.
Upgrade Firmware:
The software provided for firmware upgrade will not be capable to affect any RF parameters as
certified for he FCC for this module, in order to prevent compliance issues.
End product labeling:
This transmitter module is authorized only for use in device where the antenna may be installed
such that 20 cm may be maintained between the antenna and users. The final end product must
be labeled in a visible area with the following: “Contains 2APJ4-SLM550”
Information that must be placed in the end user manual:
The OEM integrator has to be aware not to provide information to the end user regarding how to
install or remove this RF module in the user's manual of the end product which integrates this
module. The end user manual shall include all required regulatory information/warning as show in
this manual.
When the module is installed inside another device, the user manual of the host must contain
below warning statements:
1. This device complies with part 15 of the FCC Rules. Operation is subject to the following two
conditions:
(1) This device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that may cause
undesired
Any company of the host device which installs this modular with unlimited modular approval should
perform the test of radiated & conducted emission and spurious emission, etc. according to FCC
CFR Title 47 Part 15 Subpart C Section 1R Title 47 Part 15 Subpart E Section15.407: 2016 and
FCC CFR Title 47 Part 2/ FCC CFR Title 47 Part22/ FCC CFR Title 47 Part24/ FCC CFR Title 47
Part27/ FCC CFR Title 47 Part90 and FCC Part 15B requirement, only if the tests result comply
with standards requirement, then the host can be sole legally.
Canada Statement
This device complies with Industry Canada’s licence-exempt RSSs. Operation is subject to the
following two conditions:
(1) This device may not cause interference; and
(2) This device must accept any interference, including interference that may cause undesired
operation of the device.
Le présent appareil est conforme aux CNR d’Industrie Canada applicables aux appareils radio
exempts de licence. L’exploitation est autorisée aux deux conditions suivantes :
(1) l’appareil ne doit pas produire de brouillage;
(2) l’utilisateur de l’appareil doit accepter tout brouillage radioélectrique subi, même si le
brouillage est susceptible d’en compromettre le fonctionnement.
Please notice that if the ISED certification number is not visible when the module is installed
inside another device, then the outside of the device into which the module is installed must also
display a label referring to the enclosed module. This exterior label can use wording such as the
following: “Contains IC:23860-SLM550” any similar wording that expresses the same meaning
may be used.
l'appareil hôte doit porter une étiquette donnant le numéro de certification du module d'Industrie
Canada, précédé des mots " Contient un module d'émission ", du mot IC:23860-SLM550 ou
d'une formulation similaire exprimant le même sens, comme suit
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This equipment should be installed and operated with a minimum distance of 40centimeters
between the radiator and your body. This module is installed on the host equipment and
requires a Permissive Class II Change test if the exposure conditions change.
Cet équipementdevrait être installé et actionné avec une distance minimum de 40 centimètres
entre le radiateur et votre corps. Ce module est installé sur l'équipement hôte et nécessite un
test de changement permissif de classe II si les conditions d'exposition changent.
The device for operation in the band 5150-5250 MHz is only for indoor use to reduce the
potential for harmful interference to co-channel mobile satellite systems
for devices with detachable antenna(s), the maximum antenna gain permitted for devices in
the band 5725-5850 MHz shall be such that the equipment still complies with the e.i.r.p. limits
as appropriate;
Les dispositifs fonctionnant dans la bande 5150-5250 MHz sont réservés uniquement pour
une utilisation à l’intérieur afin de réduire les risques de brouillage préjudiciable aux systèmes
de satellites mobiles utilisant les mêmes canaux;
pour les dispositifs munis d'antennes amovibles, le gain maximal d'antenne permis (pour les
dispositifs utilisant la bande de 5 725 à 5 850 MHz) doit être conforme à la limite de la p.i.r.e.
spécifiée, selon le cas;
Frequency bands 5470-5600 MHz and 5650-5725 MHz
Until further notice, devices subject to thissectionshall not be capable of transmitting in the
band 5600-5650 MHz. This restriction is for the protection of Environment Canada’s weather
radars operatingin this band.
Bandes 5470-5600MHz et 5650-5725MHz
Jusqu'à nouvel ordre, les équipements visés par la présente section ne peuvent pas être
transférés sur la bande de 5 600 à 5 650 MHz, afin de protéger l'environnement des radars
météorologiques exploités par le Canada surcette bande.
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Contents
Important Notice ....................................................................................................................................... 1
Revision History ....................................................................................................................................... 2
SLM550 Hardware Design Guide_V1.02................................................................................................. 3
Contents .................................................................................................................................................... 6
1 Introduction.......................................................................................................................................... 8
2 Module overview ................................................................................................................................. 9
2.1 Summary of features ................................................................................................................... 9
2.2 Block diagram ........................................................................................................................... 11
3 Module Package ................................................................................................................................ 13
3.1 Pin distribution diagram ............................................................................................................ 13
3.2 Pin definitions ............................................................................................................................ 14
3.3 Mechanical Dimensions ............................................................................................................ 34
4 Interface application ......................................................................................................................... 36
4.1 Power Supply ............................................................................................................................ 36
4.1.1 Power Pin........................................................................................................................ 37
4.2 Power on and off ....................................................................................................................... 37
4.2.1 Module Boot .................................................................................................................... 37
4.2.2 Module Shutdown ........................................................................................................... 39
4.2.3 Module Reset .................................................................................................................. 39
4.3 VCOIN Power ............................................................................................................................ 40
4.4 Power Output ............................................................................................................................ 41
4.5 Serial Port ................................................................................................................................. 42
4.6 MIPI Interface ............................................................................................................................ 44
4.6.1 LCD Interface .................................................................................................................. 44
4.6.2 MIPI Camera Interface .................................................................................................. 46
4.7 Capacitive Touch Interface ........................................................................................................ 50
4.8 Audio Interface .......................................................................................................................... 51
4.8.1 Receiver Interface Circuit ............................................................................................... 52
4.8.2 Microphone receiving Circuit .......................................................................................... 52
4.8.3 Headphone Interface Circuit ........................................................................................... 52
4.8.4 LINE OUT Circuit ............................................................................................................ 53
4.8.5 I2S Interface ................................................................................................................... 53
4.9 USB Interface ............................................................................................................................ 54
4.9.1 USB OTG ........................................................................................................................ 56
4.10 Charging Interface ................................................................................................................... 56
4.10.1 Charging Detection ....................................................................................................... 57
4.10.2 Charge Control ............................................................................................................. 57
4.10.3 BAT_CON_TEM ........................................................................................................... 57
4.11 UIM Card Interface ................................................................................................................... 58
4.12 SD Card Interface .................................................................................................................... 59
4.13 I2C Bus Interface ..................................................................................................................... 59
4.14 Analog to Digital Converter (ADC) ........................................................................................... 60
4.15 PWM......................................................................................................................................... 60
4.16 Motor ........................................................................................................................................ 61

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4.17 Antenna Interface..................................................................................................................... 61
4.17.1 Main Antenna................................................................................................................. 61
4.17.2 DRX Antenna ................................................................................................................. 62
4.17.3 GPS Antenna ................................................................................................................. 63
4.17.4 Wi-Fi/BT antenna........................................................................................................... 63
5 PCB Layout ........................................................................................................................................ 65
5.1 Module PIN distribution............................................................................................................. 65
5.2 PCB Layout Principles .............................................................................................................. 65
5.2.1 Antenna........................................................................................................................... 65
5.2.2 Power Supply.................................................................................................................. 66
5.2.3 SIM Card......................................................................................................................... 66
5.2.4 MIPI.................................................................................................................................66
5.2.5 USB.................................................................................................................................67
5.2.6 Audio............................................................................................................................... 67
5.2.7 Safety clearance............................................................................................................. 68
6 Electrical, Reliability ......................................................................................................................... 69
6.1 Absolute Maximum.................................................................................................................... 69
6.2 Working Temperature................................................................................................................ 69
6.3 Working Voltage........................................................................................................................ 69
6.4 Digital Interface Features.......................................................................................................... 70
6.5 SIM_VDD Characteristics ......................................................................................................... 70
6.6 PWRKEY Feature ..................................................................................................................... 70
6.7 VCOIN Feature ......................................................................................................................... 71
6.8 Current Consumption (VBAT = 3.8V)........................................................................................ 71
6.9 Electrostatic Protection ............................................................................................................. 72
6.10 Module Operating Frequency Band......................................................................................... 72
6.11 RF Characteristics.................................................................................................................... 73
6.12 Module Conduction Receiving Sensitivity................................................................................ 74
6.13 WIFI Main RF Performance ..................................................................................................... 76
6.14 BT Main RF Prformance .......................................................................................................... 77
6.15 GNSS Main RF Performance .................................................................................................. 77
7 Production.......................................................................................................................................... 78
7.1 Top And Bottom Views Of The Module ..................................................................................... 78
7.2 Recommended Soldering Furnace Temperature Curve........................................................... 79
7.3 Humidity Sensitivity (MSL)........................................................................................................ 79
7.4 Baking Requirements................................................................................................................ 80
8 Support Peripheral Device List........................................................................................................ 81
9 Appendix ............................................................................................................................................ 83
9.1 Related Documents .................................................................................................................. 83
9.2 Terms and Explanations............................................................................................................ 83
9.3 Multiplexing function ................................................................................................................. 85
9.4 Safety Warning.......................................................................................................................... 87

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1 Introduction
This document describes the hardware application interface of the module, including the connection of
the circuit and the RF interface. It can help users quickly understand the interface definition, electrical
performance, and structural dimensions of the module. Combining this document with other application
documents, users can quickly use modules to design mobile communication applications.

MeiG_SLM550_Hardware Design Manual
MeiG Smart Technology Co., Ltd
2 Module overview
SLM550 module uses the Qualcomm solution based on Arm Cortex-A53 Quad-core applications
processor, with the highest main frequency of 4 * 2.0GHz, and the memory supports Dual-channel
LPDDR4X SDRAM. This module is suitable for broadband intelligent wireless communication modules
of TD-LTE/FDD-LTE/WCDMA/EVDO/TD-SCDMA/CDMA/GSM network standards.
The working frequency band supported by SLM550 module is:
SLM550-C SLM550-E SLM550-A
TDD-LTE :B34/38/39/40/41
FDD-LTE :B1/B3/B5/B8
WCDMA:B1/5/8
GSM:B3/8
TDSCDMA: B34/39
CDMA:BC0
EVDO:BC0
TDD-LTE:B38/40/41
FDD-LTE:B1/3/5/7/8/20/28A
WCDMA:B1/5/8
GSM:2/3/5/8
FDD-
LTE:B2/4/5/7/12/13/17/25/26/66
WCDMA:B2/4/5/8
GSM:B2/5
The physical interface of the module is a 274-pin pad that provides the following hardware interfaces:
⚫Three 1.8V UART serial ports, supporting four or two wires.
⚫Main LCD（MIPI interface）.
⚫Two groups of Camera interface（MIPI data）.
⚫A high-speed USB interface.
⚫Three groups of Audio input interface.
⚫Three groups of Audio output interface.
⚫Dual- SIM card interface.
⚫GPIO interface.
⚫Five groups of I2C interfaces.
⚫One sets of SPI interfaces.
⚫TF card interface.
⚫Support GNSS，WiFi，Bluetooth 4.1 functions.
2.1 Summary of features
Table 1 SLM550 features
Product
characteristics Description
CPU Quad-core A53 (64bit) 2.0GHz
GPU Adreno 702 @845MHz
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System memory 64GB eMMC + 3GB LPDDR4X compatible with 32GB+2GB
OS Android 11
Size 40.5x40.5x2.8mm，LCC 146pin+LGA 128pin
Wi-Fi IEEE 802.11b/g/n 2.4G 802.11a/n/ac 5G
Bluetooth BT 4.2/5.0
FM No support
GNSS GPS/Beidou/Glonass
Data
Access
TD-LTE Cat4 TD-LTE 117/30Mbps
FDD-LTE Cat4 FDD-LTE 150/50Mbps
DC-HSPA+ 42/11.2Mbps
TD-HSPA 2.8/2.3Mbps
EVDO
Rev.A 3.1/1.8Mbps
EDGE Class12, 236.8kbps/236.8kbps
GPRS Class12, 85.6kbps/85.6kbps
SIM
DSDS(Dual Sim-card Dual Stanby)
3.0/1.8V
Support SIM hot plug
L/W/G+G with CSFB to W/G
L/TDS/G+G with CSFB to TDS/G
L/EVDO/CDMA1X+ G
L/W/TDS/G+CDMA1X
Don’t support dual CDMA SIM card
Display
Matrix:
HD+：1680*720 60fps
LCD Size: User defined
Interface: One MIPI DSI 4-lane;
Camera
(Front and Rear)
Interface: main: MIPI CSI 4-lanes; front: MIPI CSI 4-lanes
Camera Pixel: Max. Rear 13Mp/Front up to 13/25Mp
Video decode 1080p 30 fps: 8-bit H.264
1080p 30 fps: 8-bit HEVC (H.265) , VP9
Video encode 1080p 30 fps: 8-bit H.264
1080p 30 fps: 8-bit HEVC (H.265)

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Input Device
Key (Power on/off, Reset , Home, Volume+, Volume-)
Capacitive TP
Reset Support HW reset
Application interface
Interface name Main function description
VBAT 4pin，Power input，3.4V～4.2V，Nominal value3.8V
SDIO *1 TF Card，Support 256GB max
USB
Support OTG，Support Type-C (optional)
USB_BOOT（Force USB boot for emergency
downloads）
QUP ports 10ports (x4 in LPI)
UART*3 Max up to 4 Mbps
I2C*5 Support
SPI(master only) Support
ADC*1 Support
PWM*1 Support
Charge Max up to 2A
Vibrator Support
GPIO 40 GPIOs，Excluded BLSP multiplexing GPIO.
VCOIN Real time clock backup battery
RF Interface
Multimode LTE main antenna
Multimode LTE diversity antenna
The GPS antenna
2.4G +5G WiFi/BT antenna
Audio
One main MIC
One noise reduction MIC
One Handsfree speaker.
One earpiece
One stereo headphone.
2.2 Block diagram
The following figure lists the main functional parts of the module:

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⚫baseband chip
⚫power management chip
⚫Transceiver chip
⚫WCN3950-WIFI/BT Two in one chip
⚫Antenna interface
⚫LCD/CAM-MIPI interface
⚫EMCP memory chip
⚫AUDIO interface
⚫UART, SD card interface，SIM card interface，I2Cinterface,etc.
QCM2290
Baseband
PM4125
PMIC
WTR2965
Transceiver
16EM16-
M4CTB29-GA70
eMCP
PA
PAM
LNA
Switch
ANT_MAIN ANT_DIVANT_GNSS
VBAT
PWRKEY
ADCs
VDD_1.8V
USB (U)SIMx2 I2S UARTsI2C
RESET_N
38.4M
XO
STATUS
GPIOs
SAW
Duplex
SAW
Tx
PRx DRx
DSI SD SPI
CSI
SAW
WCN3950
WIFI/BT
Duplex
WIFI&BT
2.4G 5G
PWM
Figure 4 Module function block diagram

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3 Module Package
3.1 Pin distribution diagram
Figure 5 Module pin diagram (top view)
109
110
115 114 113 112 111 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 144 143 142 141 140 139 138 137 146 145
53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 45 46 47 48 49 50 51 52 38 39 40 41 42 43 44
37
30
31
32
33
34
35
36
18
19
20
21
22
23
24
25
26
27
28
29
17
3
1
4
5
6
7
2
VB AT
VB AT
GND
8
9
10
11
12
13
14
15
16
SD_CLK
SD_LD O21
Po w e r Pi ns GND Pins
Si gnal Pins
148
147
149
150
74
81
80
79
78
77
76
75
93
92
91
90
89
88
87
86
85
84
83
82
94
108
107
106
105
104
103
102
101
100
99
98
97
96
95
152
151
153
154
155
156
271
188
187
189
190
192
191
193
194
195
196
223
222
224
225
227
226
228
229
230
197
250
221
251
252
254
253
255
256
231
198
249
220
270
248
219
269
247
218
268
246
217
267
245
216
266
244
215
243
213
214
212
175
176
174
274
272 273
232
257
199
233
258
200
234
259
201
235
260
202
236
261
203
237
238
204
206
207
205
168
169
167
265
263
264
262
242
240
241
239
211
209
210
208
173
171
172
170
186 185 184 183 182 181 180 179 178 177
157 158 159 160 161 162 163 164 165 166
MIC1_P
MIC_GND
MIC2_P
GND
EA R_P
EA R_N
LINE_OUT_P
GND
USB_DM
LINE_OUT_N
USB_DP
GND
USB_ID
USIM 2_DET
USIM 2_RST
USIM2_CLK
USIM 2_DATA
USIM 2_VDD
USIM 1_DET
USIM 1_RST
USIM1_CLK
USIM 1_DATA
USIM 2_VDD
GND
VI B_DRV_P
PWM
TP_INT
TP_RST
SD_LD O4
GPIO_108
UART2_TXD
UART2_RXD
UART2_CTS
UART2_RTS
SD_CMD
SD_DATA0 SD_DATA1 SD_DATA2 SD_DATA3
USB_BO OT
SD_DET
TP_I2C_SCL
TP_I2C_SDA
LCD _RST
LCD _TE
GND
DSI_CLK_P
DSI_CLK_N
DSI_LN 0_N
DSI_LN 0_P
DSI_LN 1_N
DSI_LN 1_P
DSI_LN 2_N
DSI_LN 3_N
DSI_LN 2_P
DSI_LN 3_P
GND
CSI1_CLK_N
CSI1_CLK_P
CSI1_LN 0_N
CSI1_LN 0_P
CSI1_LN 1_N
CSI1_LN 1_P
GND
CSI1_LN 3_N
CSI1_LN 3_P
CSI1_LN 2_N
CSI1_LN 2_P
GPIO_33
GPIO_34
GPIO_32
GPIO_35
GPIO_39
GPIO_98
GPIO_99
GPIO_101
GPIO_100
GP IO_10 3
GP IO_36
PM_GP IO_1
GPIO_31
VO L_DOW N
VO L_UP
DBG_TXD
DBG_RXD
SENSOR_I2C_SDA
GPIO_102
GND
GND
ANT_MAIN
GND
GND
CAM_I2C_SDA
CAM_I2C_SCL
SCAM_PWDN
SCAM _RST
M CA M _PW D N
M CA M_ R ST
GND
ANT_W IFI/BT
GND
SCAM _M CLK
M CA M _M CL K
GPIO_38
VB AT
VB AT
GND
GND
VB US
VB US
GND
HPH_L
HSDET_L
CDC_HPH_REF
HPH_R
GND
BATT_THERM
VB AT_SN S_P
ANT_DRV
PA CK _ VS NS _ M
GND
LDO 20_2P85
ADC
GPIO_113
VCOI N
GPIO_114
NC
PM_GP IO_4
GND
ANT_GNSS
GND
GPIO_15
GPIO_14 GPIO_17 GPIO_16
GPIO_105
PWRKEY
GPIO_107
GP IO_10 6
LDO 15_1V8

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3.2 Pin definitions
Table 2 Pin description
Pin number Pin number I/O Description Comment
The power supply
VBAT 1, 2, 145,146 I
The module provides Four
VBAT power pin pins. The
SLM550 operates from a
single supply with a voltage
range from 3.4V to 4.2V for
VBAT.
Externally, large
capacito-rs and
Zener diodes
must be added
for surge protec-
tion.
VBUS 141, 142 I/O 5V charging input power.
VCOIN 126 I/O
When the VBAT of the
system power is absent, the
external backup battery
provides power to the system
real-time clock.When VBAT is
present, the backup battery is
charged.
VCOIN pins
connect 3V
button batteries
or large
capacitors.
L15_1P8 111 O
1.8V power output, Power
supply always available for
IO port pull-up and level
conver-sion, not for
peripheral power supply
50mA
NC 125
L17_2P8 156 O 2.8V power output, used for
Sensor, TP power supply. 150mA
L20_2P85 129 O 2.85 V power output, for
LCD, Camera 2.8V. 300mA
SD_L21 38 O TF card power supply pin 500mA
SD_L4 32 O TF card signal pull-up power
supply pin 50mA
UIM1_VDD 26 O UIM power supply pins 50mA
UIM2_VDD 21 O UIM power supply pins 50mA
NC 193
GND
3, 7, 12, 15,
27, 51, 62, 69,
76, 78, 85, 86,
GND

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88, 89, 120,
122, 130, 132,
135, 140, 143,
144, 149, 162,
171, 172, 176,
187~191,
202~204
206~224,
226~231
233~238, 240,
241, 243, 244,
245, 247, 248,
250, 251, 255,
256, 258, 259,
261, 266, 268,
269, 271~274
display interface (MIPI)
DSI_CLK_N 52 I/O
MIPI_LCD clock
DSI_CLK_P 53 I/O
DSI_LN0_N 54 I/O
MIPI_LCD data
DSI_LN0_P 55 I/O
DSI_LN1_N 56 I/O
DSI_LN1_P 57 I/O
DSI_LN2_N 58 I/O
DSI_LN2_P 59 I/O
DSI_LN3_N 60 I/O
DSI_LN3_P 61 I/O
GPIO82_LCD0_RESE
T 49 O LCD reset
GPIO81_LCD_TE 50 I/O LCD frame sync signal
UART(1.8V)
GPIO2_UART1_TXD 154 I UART1 data transmit
GPIO3_UART1_RXD 153 O UART1 data receive

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GPIO12_DBG_UART_
TX 94 I UART5 data receive
GPIO13_DBG_UART_
RX 93 O UART5 data transmit
GPIO69_UART2_TXD 34 I UART2 data receive
GPIO70_UART2_RXD 35 O UART2 data transmit
GPIO4_UART2_CTS 36 I UART2 Clear To Send
（CTS）
GPIO5_UART2_RTS 37 O UART2 Request To Send
（RTS）
UIM card Interface
GPIO79_UIM1_DET 22 I UIM1 insert detect
UIM1_RESET 23 O UIM1 reset
UIM1_CLK 24 O UIM1 clock
UIM1_DATA 25 I/O UIM1 data
GPIO75_UIM2_DET 17 I UIM2 insert detect
UIM2_RESET 18 O UIM2 reset
UIM2_CLK 19 O UIM2 clock
UIM2_DATA 20 I/O UIM2 data
Front Camera
CSI0_CLK_N 157 I/O
Front Camera MIPI clock
CSI0_CLK_P 196 I/O
CSI0_LN0_N 158 I/O
Front Camera MIPI data
CSI0_LN0_P 197 I/O
CSI0_LN1_N 159 I/O
CSI0_LN1_P 198 I/O
CSI0_LN2_N 160 I/O
CSI0_LN2_P 199 I/O
CSI0_LN3_N 161 I/O

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CSI0_LN3_P 200 I/O
GPIO27_SCAM_MCL
K2 75 I/O Front Camera main clock
GPIO24_SCAM_RST_
N 81 I/O Front Camera reset
GPIO26_SCAM_PWD
N 82 I/O Front Camera dormancy
Rear Camera
CSI1_CLK_N 63 I/O
Rear Camera MIPI clock
CSI1_CLK_P 64 I/O
CSI1_LN0_N 65 I/O
Rear Camera MIPI data
CSI1_LN0_P 66 I/O
CSI1_LN1_N 67 I/O
CSI1_LN1_P 68 I/O
CSI1_LN2_N 72 I/O
CSI1_LN2_P 73 I/O
CSI1_LN3_N 70 I/O
CSI1_LN3_P 71 I/O
GPIO21_MCAM_MCL
K1 74 I/O Rear Camera main clock
GPIO19_MCAM_RST
_N 79 I/O Rear Camera reset
GPIO25_MCAM_PWD
N 80 I/O Rear Camera dormancy
Audio Interface
MIC_GND 5 The main MIC negative
MIC_IN1_P 4 I The main MIC positive
MIC_IN2_P 6 I Headphone MIC positive
MIC_IN3_P 148 I Secondary MIC positive
MIC_BIAS1 147 O
The BIAS voltage of main
MIC is used in the design of
silicon wheat