Quectel SC20-WL Supplement

SC20-WL Hardware Design
Smart Wi-Fi Module Series
Rev: SC20-WL_Hardware_Design_V1.0
Date: 2019-12-16
www.quectel.com

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About the Document
History
Revision
Date
Author
Description
1.0
2019-12-16
Quinn.lv
Initial

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Contents
About the Document...................................................................................................................................2
Contents.......................................................................................................................................................3
Table Index...................................................................................................................................................5
Figure Index.................................................................................................................................................6
1Introduction........................................................................................................................................11
1.1. Safety Information....................................................................................................................11
2Product Concept................................................................................................................................13
2.1. General Description.................................................................................................................13
2.2. Key Features ...........................................................................................................................14
2.3. Functional Diagram .................................................................................................................16
2.4. Evaluation Board .....................................................................................................................17
3Application Interfaces .......................................................................................................................18
3.1. General Description.................................................................................................................18
3.2. Pin Assignment........................................................................................................................19
3.3. Pin Description.........................................................................................................................20
3.4. Power Supply...........................................................................................................................29
3.4.1. Power Supply Pins.........................................................................................................29
3.4.2. Decrease Voltage Drop..................................................................................................29
3.4.3. Reference Design for Power Supply..............................................................................30
3.5. Turn on and off Scenarios .......................................................................................................31
3.5.1. Turn on Module Using the PWRKEY.............................................................................31
3.5.2. Turn off Module..............................................................................................................33
3.6. VRTC Interface........................................................................................................................34
3.7. Power Output...........................................................................................................................35
3.8. Battery Charge and Management...........................................................................................35
3.9. USB Interface ..........................................................................................................................37
3.10. UART Interfaces......................................................................................................................39
3.11. SD Card Interface....................................................................................................................40
3.12. GPIO Interfaces.......................................................................................................................42
3.13. SPI Interface............................................................................................................................44
3.14. I2C Interfaces ..........................................................................................................................45
3.15. ADC Interfaces ........................................................................................................................46
3.16. Motor Drive Interface...............................................................................................................46
3.17. LCM Interface..........................................................................................................................47
3.18. Touch Panel Interface..............................................................................................................50
3.19. Camera Interfaces...................................................................................................................51
3.19.1. Rear Camera Interface...................................................................................................51
3.19.2. Front Camera Interface..................................................................................................53
3.19.3. Design Considerations...................................................................................................55
3.20. Sensor Interfaces.....................................................................................................................56

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3.21. Audio Interfaces.......................................................................................................................57
3.21.1. Reference Circuit Design for Microphone......................................................................58
3.21.2. Reference Circuit Design for Receiver Interface...........................................................58
3.21.3. Reference Circuit Design for Headphone Interface.......................................................59
3.21.4. Reference Circuit Design for Loudspeaker Interface.....................................................59
3.21.5. Audio Interface Design Considerations .........................................................................59
3.22. Emergency Download Interface..............................................................................................60
4Wi-Fi and BT.......................................................................................................................................61
4.1. Wi-Fi Overview ........................................................................................................................61
4.1.1. Wi-Fi Performance.........................................................................................................61
4.2. BT Overview ............................................................................................................................63
4.2.1. BT Performance.............................................................................................................64
5Antenna Interface...............................................................................................................................65
5.1. Wi-Fi/BTAntenna Interface .....................................................................................................65
5.1.1. Reference Design of RF Layout.....................................................................................66
5.2. Antenna Installation.................................................................................................................68
5.2.1. Antenna Requirements ..................................................................................................68
5.2.2. Recommended RF Connector for Antenna Installation.................................................68
6Electrical, Reliability and Radio Characteristics............................................................................70
6.1. Absolute Maximum Ratings.....................................................................................................70
6.2. Power Supply Ratings.............................................................................................................70
6.3. Charging Performance Specifications.....................................................................................71
6.4. Operation and StorageTemperatures......................................................................................71
6.5. Current Consumption ..............................................................................................................72
6.6. Electrostatic Discharge............................................................................................................73
7Mechanical Dimensions....................................................................................................................74
7.1. Mechanical Dimensions of the Module....................................................................................74
7.2. Recommended Footprint.........................................................................................................76
7.3. Top and Bottom Views of the Module......................................................................................77
8Storage, Manufacturing and Packaging..........................................................................................78
8.1. Storage.....................................................................................................................................78
8.2. Manufacturing and Soldering ..................................................................................................79
8.3. Packaging................................................................................................................................80
9Appendix A References.....................................................................................................................82

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Table Index
TABLE 1: SC20-WL FREQUENCY BANDS...................................................................................................... 13
TABLE 2: SC20-WL KEY FEATURES............................................................................................................... 14
TABLE 3: I/O PARAMETERS DEFINITION....................................................................................................... 20
TABLE 4: PIN DESCRIPTION........................................................................................................................... 20
TABLE 5: POWER DESCRIPTION................................................................................................................... 35
TABLE 6: PIN DEFINITION OF USB INTERFACE ........................................................................................... 37
TABLE 7: USB TRACE LENGTH INSIDE THE MODULE................................................................................. 38
TABLE 8: PIN DESCRIPTION OF UART INTERFACES .................................................................................. 39
TABLE 9: PIN DEFINITION OF SD CARD INTERFACE .................................................................................. 40
TABLE 10: SDIO TRACE LENGTH INSIDE THE MODULE............................................................................. 42
TABLE 11: PIN DEFINITION OF GPIO INTERFACES...................................................................................... 42
TABLE 12: PIN DEFINITION OF SPI INTERFACE........................................................................................... 45
TABLE 13: PIN DEFINITION OF I2C INTERFACE........................................................................................... 45
TABLE 14: PIN DEFINITION OF ADC INTERFACES....................................................................................... 46
TABLE 15: PIN DEFINITION OF MOTOR DRIVE INTERFACE ....................................................................... 46
TABLE 16: PIN DEFINITION OF LCM INTERFACE......................................................................................... 47
TABLE 17: PIN DEFINITION OF TOUCH PANEL INTERFACE ....................................................................... 50
TABLE 18: PIN DEFINITION OF REAR CAMERA INTERFACE ...................................................................... 52
TABLE 19: PIN DEFINITION OF FRONT CAMERA INTERFACE.................................................................... 53
TABLE 20: MIPI TRACE LENGTH INSIDE THE MODULE............................................................................... 55
TABLE 21: PIN DEFINITION OF SENSOR INTERFACES............................................................................... 56
TABLE 22: PIN DEFINITION OF AUDIO INTERFACES................................................................................... 57
TABLE 23: Wi-Fi TRANSMITTING PERFORMANCE....................................................................................... 61
TABLE 24: Wi-Fi RECEIVING PERFORMANCE.............................................................................................. 62
TABLE 25: BT DATA RATE AND VERSION...................................................................................................... 63
TABLE 26: BT TRANSMITTING AND RECEIVING PERFORMANCE ............................................................. 64
TABLE 27: PIN DEFINITION OF Wi-Fi/BT ANTENNA...................................................................................... 65
TABLE 28: Wi-Fi/BT FREQUENCY................................................................................................................... 65
TABLE 29: ANTENNA REQUIREMENTS.......................................................................................................... 68
TABLE 30: ABSOLUTE MAXIMUM RATINGS.................................................................................................. 70
TABLE 31: SC20-WL MODULE POWER SUPPLY RATINGS.......................................................................... 70
TABLE 32: CHARGING PERFORMANCE SPECIFICATIONS......................................................................... 71
TABLE 33: OPERATION TEMPERATURE........................................................................................................ 71
TABLE 34: SC20-WL CURRENT CONSUMPTION .......................................................................................... 72
TABLE 35: ESD CHARACTERISTICS (TEMPERATURE: 25°C, HUMIDITY: 45%)......................................... 73
TABLE 36: RECOMMENDED THERMAL PROFILE PARAMETERS............................................................... 79
TABLE 37: REEL PACKAGING......................................................................................................................... 81
TABLE 38: RELATED DOCUMENTS................................................................................................................ 82
TABLE 39: TERMS AND ABBREVIATIONS...................................................................................................... 82

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Figure Index
FIGURE 1: FUNCTIONAL DIAGRAM ............................................................................................................... 17
FIGURE 2: PIN ASSIGNMENT (TOP VIEW)..................................................................................................... 19
FIGURE 3: VOLTAGE DROP SAMPLE............................................................................................................. 30
FIGURE 4: POWER SUPPLY ........................................................................................................................... 30
FIGURE 5: REFERENCE CIRCUIT OF POWER SUPPLY .............................................................................. 31
FIGURE 6: TURN ON THE MODULE USING DRIVING CIRCUIT................................................................... 32
FIGURE 7: TURN ON THE MODULE USING KEYSTROKE ........................................................................... 32
FIGURE 8: TIMING OF TURNING ON MODULE ............................................................................................. 33
FIGURE 9: TIMING OF TURNING OFF MODULE ........................................................................................... 34
FIGURE 10: RTC POWERED BY COIN CELL................................................................................................. 34
FIGURE 11: RTC POWERED BY CAPACITOR................................................................................................ 34
FIGURE 12: REFERENCE DESIGN FOR BATTERY CHARGING CIRCUIT................................................... 36
FIGURE 13: USB INTERFACE REFERENCE DESIGN (OTG IS NOT SUPPORTED) ................................... 37
FIGURE 14: USB INTERFACE REFERENCE DESIGN (OTG IS SUPPORTED)............................................ 38
FIGURE 15: REFERENCE CIRCUIT WITH LEVEL TRANSLATOR CHIP (FOR UART1) ............................... 39
FIGURE 16: RS232 LEVEL MATCH CIRCUIT (FOR UART1).......................................................................... 40
FIGURE 17: REFERENCE CIRCUIT FOR SD CARD INTERFACE................................................................. 41
FIGURE 18: REFERENCE CIRCUIT FOR MOTOR CONNECTION................................................................ 47
FIGURE 19: REFERENCE CIRCUIT DESIGN FOR LCM INTERFACE........................................................... 49
FIGURE 20: REFERENCE DESIGN FOR BACKLIGHT DIRVING CIRCUIT................................................... 50
FIGURE 21: REFERENCE CIRCUIT DESIGN FOR TP INTERFACE.............................................................. 51
FIGURE 22: REFERENCE CIRCUIT DESIGN FOR REAR CAMERA INTERFACE........................................ 53
FIGURE 23: REFERENCE CIRCUIT DESIGN FOR FRONT CAMERA INTERFACE...................................... 54
FIGURE 24: REFERENCE CIRCUIT DESIGN FOR MICROPHONE INTERFACE ......................................... 58
FIGURE 25: REFERENCE CIRCUIT DESIGN FOR RECEIVER INTERFACE................................................ 58
FIGURE 26: REFERENCE CIRCUIT DESIGN FOR HEADPHONE INTERFACE ........................................... 59
FIGURE 27: REFERENCE CIRCUIT DESIGN FOR LOUDSPEAKER INTERFACE....................................... 59
FIGURE 28: REFERENCE CIRCUIT DESIGN FOR EMERGENCY DOWNLOAD INTERFACE..................... 60
FIGURE 29: REFERENCE CIRCUIT DESIGN FOR Wi-Fi/BTANTERNNA..................................................... 65
FIGURE 30: MICROSTRIP LINE DESIGN ON A 2-LAYER PCB...................................................................... 66
FIGURE 31: COPLANAR WAVEGUIDE LINE DESIGN ON A 2-LAYER PCB.................................................. 66
FIGURE 32: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 3 AS REFERENCE
GROUND).......................................................................................................................................................... 67
FIGURE 33: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 4 AS REFERENCE
GROUND).......................................................................................................................................................... 67
FIGURE 34: DIMENSIONS OF THE U.FL-R-SMT CONNECTOR (UNIT: MM)................................................ 68
FIGURE 35: MECHANICAL PARAMETERS OF U.FL-LP CONNECTORS...................................................... 69
FIGURE 36: SPACE FACTOR OF MATED CONNECTORS (UNIT: MM)......................................................... 69
FIGURE 37: MODULE TOPAND SIDE DIMENSIONS..................................................................................... 74
FIGURE 38: MODULE BOTTOM DIMENSIONS (TOP VIEW)......................................................................... 75
FIGURE 39: RECOMMENDED FOOTPRINT (TOP VIEW).............................................................................. 76

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FIGURE 40: TOP VIEWS OF THE MODULE ................................................................................................... 77
FIGURE 41: BOTTOM VIEW OF THE MODULE.............................................................................................. 77
FIGURE 42: REFLOW SOLDERING THERMAL PROFILE.............................................................................. 79
FIGURE 43: TAPE DIMENSIONS..................................................................................................................... 80
FIGURE 44: REEL DIMENSIONS..................................................................................................................... 81

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OEM/Integrators Installation Manual
Important Notice to OEM integrators
1. This module is limited to OEM installation ONLY.
2. This module is limited to installation in mobile or fixed applications, according to Part 2.1091(b).
3. The separate approval is required for all other operating configurations, including portable
configurations with respect to Part 2.1093 and different antenna configurations
4. For FCC Part 15.31 (h) and (k): The host manufacturer is responsible for additional testing to verify
compliance as a composite system. When testing the host device for compliance with Part 15 Subpart B,
the host manufacturer is required to show compliance with Part 15 Subpart B while the transmitter
module(s) are installed and operating. The modules should be transmitting and the evaluation should
confirm that the module's intentional emissions are compliant (i.e. fundamental and out of band
emissions). The host manufacturer must verify that there are no additional unintentional emissions other
than what is permitted in Part 15 Subpart B or emissions are complaint with the transmitter(s) rule(s). The
Grantee will provide guidance to the host manufacturer for Part 15 B requirements if needed.
End Product Labeling
When the module is installed in the host device, the FCC/IC ID label must be visible through a window on
the final device or it must be visible when an access panel, door or cover is easily re-moved. If not, a
second label must be placed on the outside of the final device that contains the following text:
“Contains FCC ID: XMR201911SC20WL ”
“Contains IC: 10224A-2019SC20WL “
The FCC ID/IC ID can be used only when all FCC/IC compliance requirements are met.
In the event that these conditions cannot be met (for example certain laptop configurations or co-location
with another transmitter), then the FCC/IC authorization is no longer considered valid and the FCC ID/IC
ID 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/IC authorization.
Manual Information to the End User
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.
Federal Communication Commission Interference Statement
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 operation.
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 designed to provide reasonable protection against harmful
interference in a residential installation. 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

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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 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.
Any changes or modifications not expressly approved by the party responsible for compliance could void
the user's authority to operate this equipment. This transmitter must not be co-located or operating in
conjunction with any other antenna or transmitter.
Industry 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, et
(2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est
susceptible d'en compromettre le fonctionnement."
The device could automatically discontinue transmission in case of absence of information to transmit, or
operational failure. Note that this is not intended to prohibit transmission of control or signaling information
or the use of repetitive codes where required by the technology.
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; The maximum antenna gain permitted for
devices in the bands 5250–5350 MHz and 5470–5725 MHz shall comply with the e.i.r.p. limit; and The
maximum antenna gain permitted for devices in the band 5725–5825 MHz shall comply with the e.i.r.p.
limits specified for point-to-point and non point-to-point operation as appropriate.
L'appareil peut interrompre automatiquement la transmission en cas d'absence d'informations à
transmettre ou de panne opérationnelle. Notez que ceci n'est pas destinéàinterdire la transmission
d'informations de contrôle ou de signalisation ou l'utilisation de codes répétitifs lorsque cela est requis par
la technologie.
Le dispositif utilisédans la bande 5150-5250 MHz est réservéàune utilisation en intérieur afin de réduire
le risque de brouillage préjudiciable aux systèmes mobiles par satellite dans le même canal; Le gain
d'antenne maximal autorisépour les dispositifs dans les bandes 5250-5350 MHz et 5470-5725 MHz doit
être conforme àla norme e.r.p. limite; et Le gain d'antenne maximal autorisépour les appareils de la