Quectel BC66 Supplement

BC66 Hardware Design
NB-IoT Module Series
Rev. BC66_Hardware_Design_V1.1
Date: 2018-11-14
Status: Released
www.quectel.com

NB-IoT Module Series
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About the Document
History
Revision
Date
Author
Description
1.0
2018-08-24
Speed SUN/
Newgate HUA
Initial
1.1
2018-11-14
Newgate HUA
Updated supported bands and involved RF parameters of
BC66.

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Contents
About the Document...................................................................................................................................2
Contents.......................................................................................................................................................3
Table Index...................................................................................................................................................5
Figure Index.................................................................................................................................................6
1Introduction..........................................................................................................................................7
1.1. Safety Information.......................................................................................................................8
2Product Concept..................................................................................................................................9
2.1. General Description....................................................................................................................9
2.2. Key Features.............................................................................................................................10
2.3. Functional Diagram...................................................................................................................11
2.4. Development Board..................................................................................................................12
3Application Interfaces .......................................................................................................................13
3.1. General Description..................................................................................................................13
3.2. Pin Assignment .........................................................................................................................14
3.3. Pin Description..........................................................................................................................15
3.4. Operating Modes.......................................................................................................................18
3.5. Power Saving Mode (PSM).......................................................................................................19
3.6. Power Supply............................................................................................................................20
3.6.1. Power Supply Pins.........................................................................................................20
3.6.2. Reference Design for Power Supply..............................................................................21
3.7. Power up/Power down Scenarios.............................................................................................21
3.7.1. Turn on...........................................................................................................................21
3.7.2. Turn off...........................................................................................................................23
3.7.3. Reset the Module...........................................................................................................24
3.8. UART Interfaces........................................................................................................................25
3.8.1. Main UART Port.............................................................................................................26
3.8.2. Debug UART Port ..........................................................................................................26
3.8.3. Auxiliary UART Port .......................................................................................................27
3.8.4. UARTApplication...........................................................................................................27
3.9. SPI Interface .............................................................................................................................29
3.10. USIM Interface..........................................................................................................................30
3.11. ADC Interface............................................................................................................................32
3.12. RI Behaviors*............................................................................................................................32
3.13. Network Status Indication*........................................................................................................32
4Antenna Interface...............................................................................................................................34
4.1. Pin Definition.............................................................................................................................34
4.2. Operating Frequencies .............................................................................................................34
4.3. RFAntenna Reference Design.................................................................................................35
4.4. Reference Design of RF Layout ...............................................................................................36

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4.5. Antenna Requirements.............................................................................................................38
4.6. RF Output Power ......................................................................................................................39
4.7. RF Receiving Sensitivity...........................................................................................................40
4.8. Recommended RF Connector forAntenna Installation............................................................41
5Electrical and Reliability Characteristics........................................................................................43
5.1. Operation and Storage Temperatures.......................................................................................43
5.2. Current Consumption................................................................................................................43
5.3. Electrostatic Discharge.............................................................................................................45
6Mechanical Dimensions....................................................................................................................47
6.1. Mechanical Dimensions of the Module.....................................................................................47
6.2. Recommended Footprint ..........................................................................................................49
6.3. Top and Bottom Views of the Module.......................................................................................50
7Storage, Manufacturing and Packaging..........................................................................................51
7.1. Storage......................................................................................................................................51
7.2. Manufacturing and Soldering....................................................................................................52
7.3. Packaging .................................................................................................................................53
7.3.1. Tape and Reel Packaging..............................................................................................53
8Appendix A References.....................................................................................................................55

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Table Index
TABLE 1: FREQUENCY BANDS OF BC66 MODULE........................................................................................ 9
TABLE 2: BC66 KEY FEATURES ..................................................................................................................... 10
TABLE 3: I/O PARAMETERS DEFINITION....................................................................................................... 15
TABLE 4: PIN DESCRIPTION........................................................................................................................... 15
TABLE 5: OVERVIEW OF OPERATING MODES............................................................................................. 18
TABLE 6: POWER SUPPLY PINS..................................................................................................................... 20
TABLE 7: PWRKEY PIN.................................................................................................................................... 21
TABLE 8: RESET PIN........................................................................................................................................ 24
TABLE 9: PIN DEFINITION OF UART INTERFACES....................................................................................... 25
TABLE 10: PIN DEFINITION OF SPI INTERFACE........................................................................................... 30
TABLE 11: PIN DEFINITION OF USIM INTERFACE........................................................................................ 31
TABLE 12: PIN DEFINITION OF ADC INTERFACE ......................................................................................... 32
TABLE 13: PIN DEFINITION OF NB-IOTANTENNA INTERFACE................................................................... 34
TABLE 14: MODULE OPERATING FREQUENCIES........................................................................................ 34
TABLE 15: ANTENNA CABLE INSERTION LOSS REQUIREMENTS ............................................................. 38
TABLE 16: REQUIRED ANTENNA PARAMETERS.......................................................................................... 38
TABLE 17: RF CONDUCTED OUTPUT POWER............................................................................................. 39
TABLE 18: RECEIVING SENSITIVITY (WITH RF RETRANSMISSIONS)....................................................... 40
TABLE 19: OPERATION AND STORAGE TEMPERATURES.......................................................................... 43
TABLE 20: MODULE CURRENT CONSUMPTION .......................................................................................... 44
TABLE 21: ELECTROSTATIC DISCHARGE CHARACTERISTICS (25ºC , 45% RELATIVE HUMIDITY)........ 46
TABLE 22: RECOMMENDED THERMAL PROFILE PARAMETERS............................................................... 52
TABLE 23: RELATED DOCUMENTS................................................................................................................ 55
TABLE 24: TERMS AND ABBREVIATIONS...................................................................................................... 55

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Figure Index
FIGURE 1: FUNCTIONAL DIAGRAM ............................................................................................................... 12
FIGURE 2: PIN ASSIGNMENT ......................................................................................................................... 14
FIGURE 3: MODULE POWER CONSUMPTION IN DIFFERENT MODES...................................................... 19
FIGURE 4: TIMING OF WAKING UP MODULE FROM PSM........................................................................... 20
FIGURE 5: REFERENCE CIRCUIT FOR POWER SUPPLY............................................................................ 21
FIGURE 6: TURN ON THE MODULE USING DRIVING CIRCUIT................................................................... 22
FIGURE 7: TURN ON THE MODULE USING KEYSTROKE ........................................................................... 22
FIGURE 8: POWER UP TIMING....................................................................................................................... 22
FIGURE 9: POWER DOWN TIMING (POWER OFF BY AT COMMAND)........................................................ 23
FIGURE 10: POWER DOWN TIMING (POWER OFF BY DISCONNECTING VBAT)...................................... 23
FIGURE 11: REFERENCE CIRCUIT OF RESET BY USING DRIVING CIRCUIT ........................................... 24
FIGURE 12: REFERENCE CIRCUIT OF RESET BY USING BUTTON........................................................... 24
FIGURE 13: RESET TIMING............................................................................................................................. 25
FIGURE 14: REFERENCE DESIGN FOR MAIN UART PORT......................................................................... 26
FIGURE 15: REFERENCE DESIGN OF DEBUG UART PORT ....................................................................... 27
FIGURE 16: REFERENCE DESIGN OF AUXILIARY UART PORT.................................................................. 27
FIGURE 17: REFERENCE CIRCUIT WITH VOLTAGE LEVEL TRANSLATOR CHIP...................................... 28
FIGURE 18: REFERENCE CIRCUIT WITH TRANSISTOR CIRCUIT.............................................................. 28
FIGURE 19: SKETCH MAP FOR RS-232 INTERFACE MATCH...................................................................... 29
FIGURE 20: SPI INTERFACE REFERENCE CIRCUIT WITH TRANSLATOR CHIP....................................... 30
FIGURE 21: REFERENCE CIRCUIT FOR USIM INTERFACE WITH A 6-PIN USIM CARD CONNECTOR... 31
FIGURE 22: REFERENCE DESIGN FOR NETLIGHT ..................................................................................... 33
FIGURE 23: REFERENCE DESIGN OF NB-IOT ANTENNA INTERFACE ...................................................... 36
FIGURE 24: MICROSTRIP LINE DESIGN ON A 2-LAYER PCB...................................................................... 36
FIGURE 25: COPLANAR WAVEGUIDE LINE DESIGN ON A 2-LAYER PCB.................................................. 37
FIGURE 26: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 3 AS REFERENCE
GROUND).................................................................................................................................................. 37
FIGURE 27: COPLANAR WAVEGUIDE LINE DESIGN ON A 4-LAYER PCB (LAYER 4 AS REFERENCE
GROUND).................................................................................................................................................. 37
FIGURE 28: DIMENSIONS OF THE U.FL-R-SMT CONNECTOR (UNIT: MM)................................................ 41
FIGURE 29: MECHANICALS OF U.FL-LP CONNECTORS............................................................................. 41
FIGURE 30: SPACE FACTOR OF MATED CONNECTOR (UNIT: MM)........................................................... 42
FIGURE 31: TOP VIEW OF THE MODULE...................................................................................................... 50
FIGURE 32: BOTTOM VIEW OF THE MODULE.............................................................................................. 50
FIGURE 33: TAPE DIMENSIONS (UNIT: MM).................................................................................................. 54
FIGURE 34: REEL DIMENSIONS (UNIT: MM) ................................................................................................. 54

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1Introduction
This document defines the BC66 module and describes its air interface and hardware interface which are
connected with the customers’ applications.
This document can help customers quickly understand module interface specifications, electrical and
mechanical details, as well as other related information of the module. Associated with application notes
and user guides, customers can use BC66 to design and set up mobile applications easily.

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1.1. Safety Information
The following safety precautions must be observed during all phases of the operation, such as usage,
service or repair of any cellular terminal or mobile incorporating BC66 module. Manufacturers of the
cellular terminal should send the following safety information to users and operating personnel, and
incorporate these guidelines into all manuals supplied with the product. If not so, Quectel assumes no
liability for customers’ failure to comply with these precautions.
Full attention must be given to driving at all times in order to reduce the risk of an
accident. Using a mobile while driving (even with a handsfree kit) causes
distraction and can lead to an accident. Please comply with laws and regulations
restricting the use of wireless devices while driving.
Switch off the cellular terminal or mobile before boarding an aircraft. The operation
of wireless appliances in an aircraft is forbidden to prevent interference with
communication systems. If the device offers an Airplane Mode, then it should be
enabled prior to boarding an aircraft. Please consult the airline staff for more
restrictions on the use of wireless devices on boarding the aircraft.
Wireless devices may cause interference on sensitive medical equipment, so
please be aware of the restrictions on the use of wireless devices when in
hospitals, clinics or other healthcare facilities.
Cellular terminals or mobiles operating over radio signals and cellular network
cannot be guaranteed to connect in all possible conditions (for example, with
unpaid bills or with an invalid (U)SIM card). When emergent help is needed in such
conditions, please remember using emergency call. In order to make or receive a
call, the cellular terminal or mobile must be switched on in a service area with
adequate cellular signal strength.
The cellular terminal or mobile contains a transmitter and receiver. When it is ON, it
receives and transmits radio frequency signals. RF interference can occur if it is
used close to TV set, radio, computer or other electric equipment.
In locations with potentially explosive atmospheres, obey all posted signs to turn
off wireless devices such as your phone or other cellular terminals. Areas with
potentially explosive atmospheres include fuelling areas, below decks on boats,
fuel or chemical transfer or storage facilities, areas where the air contains
chemicals or particles such as grain, dust or metal powders, etc.

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2Product Concept
2.1. General Description
BC66 is a high-performance NB-IoT module with extremely low power consumption. It is designed to
communicate with infrastructures of mobile network operators through NB-IoT radio protocols (3GPP
Rel.13 and 3GPP Rel.14*). BC66 supports a broad range of frequency bands as listed below.
Table 1: Frequency Bands of BC66 Module
BC66 is an SMD type module with LCC package, and has an ultra-compact profile of 17.7mm ×15.8mm ×
2.0mm. These make it can be easily embedded into size-constrained applications and provide reliable
connectivity with the applications.
BC66 provides abundant external interfaces (UART, SPI*, ADC*, NETLIGHT*, etc.) and protocol stacks
(UDP/TCP, LwM2M, MQTT, etc.), which provide great convenience for customers' applications.
Due to compact form factor, ultra-low power consumption and extended temperature range, BC66 is a
best choice for a wide range of IoT applications, such as smart metering, bike sharing, smart wearables,
smart parking, smart city, home appliances, security and asset tracking, agricultural and environmental
monitoring, etc. It is able to provide a complete range of SMS* and data transmission services to meet
customers’ demands.
The module fully complies with the RoHS directive of the European Union.
“*” means under development.
Mode
BC66
H-FDD
B1/B2/B3/B4/B5/B8/B12/B13/B17/B18/B19/B20/B25/B26*/B28/B66
NOTE

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2.2. Key Features
The following table describes the detailed features of BC66 module.
Table 2: BC66 Key Features
Feature
Details
Power Supply
Supply voltage: 2.1V ~ 3.63V
Typical supply voltage: 3.3V
Power Saving
Maximum power consumption: 5μA
Typical power consumption: 3.5μA
Frequency bands
LTE Cat NB1:
B1/B2/B3/B4/B5/B8/B12/B13/B17/B18/B19/B20/B25/B26*/B28/B66
Transmitting Power
23dBm±2dB
USIM Interface
Support 1.8V USIM card
UART Interfaces
Main UART Port:
Used for AT command communication and data transmission.
By default, the module is in auto-baud mode, and it supports automatic
baud rates not exceeding 115200bps. When powering on the module, the
MCU has to send AT command consecutively to synchronize baud rate
with the module. When OK is returned, it indicates the baud rate has been
synchronized successfully. When the module is woken up from PSM or
idle mode, the baud rate synchronized during start-up will be used directly.
Also can be used for firmware upgrade, and in such case, the baud rate is
921600bps by default.
Debug UART Port:
Used for firmware debugging
Default baud rate: 115200bps
Auxiliary UART Port:
Used for firmware debugging
Default baud rate: 115200bps
Network Protocols
UDP/TCP/LwM2M/MQTT/CoAP*/PPP*/TLS*/DTLS*/HTTP*/HTTPS*
SMS*
Text/PDU Mode
Data Transmission
Features
Single-tone: 25.5kbps (DL)/16.7kbps (UL)
Multi-tone: 25.5kbps (DL )/62.5kbps (UL)
AT Commands
3GPP TS 27.005/3GPP TS 27.007 AT commands (3GPP Rel. 13/Rel.14*)
and Quectel Enhanced AT commands
Firmware Update
Upgrade firmware via main UART port or DFOTA

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1. 1) Within operation temperature range, the module is 3GPP compliant.
2. 2) Within extended temperature range, the module remains the ability to establish and maintain an
SMS*, data transmission, etc. There is no unrecoverable malfunction. There are also no effects on
radio spectrum and no harm to radio network. Only one or more parameters like Pout might reduce in
their value and exceed the specified tolerances. When the temperature returns to normal operation
temperature levels, the module will meet 3GPP specifications again.
3. "*" means under development.
2.3. Functional Diagram
The following figure shows a block diagram of BC66 and illustrates the major functional parts.
Radio frequency
Baseband
Power management
Peripheral interfaces
Real Time Clock
Supported
Physical
Characteristics
Size: (17.7±0.15)mm ×(15.8±0.15)mm ×(2.0±0.2)mm
Weight: 1.2g±0.2g
Temperature Range
Operation temperature range: -35°C ~ +75°C 1)
Extended temperature range: -40°C ~ +85°C 2)
Storage temperature range: -40°C ~ +90°C
Antenna Interface
50Ωimpedance control
RoHS
All hardware components are fully compliant with EU RoHS directive
NOTES

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RF_ANT
PA
Boost
PMU
BUCK
RF Transceiver
and Subsystem
XO
26MHz
XTAL
Baseband
RESET ADC*
MAIN_UART
AUX_URAT
Flash
PSRAM
NETLIGHT*
TX RX
32KHz
RTC BLOCK
LDO
PSM_EINT
USIM
Enable
PWRKEY
DBG_UART
USIM
SPI*
VBAT
VDD_EXT
ASM
Figure 1: Functional Diagram
“*” means under development.
2.4. Development Board
Quectel provides a complete set of development tools to facilitate the use and testing of BC66 module.
The development tool kit includes the TE-B board, USB cable, antenna and other peripherals. For more
details, please refer to document [1].
NOTE

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3Application Interfaces
3.1. General Description
BC66 is equipped with a total of 58 pins, including 44 LCC pins and 14 LGA pins. The subsequent
chapters will provide detailed descriptions of the following functions/pins/interfaces:
PSM
Power Supply
RESET
PWRKEY
UART Interfaces
SPI Interface
USIM Interface
ADC Interface
Network Status Indication*
Antenna Interface
“*”means under development.
NOTE

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3.2. Pin Assignment
15 16 17 18 19 20
21 22 36
37 38 39 40 41 42 43 44
1
2
3
4
5
6
7
8
9
10
11
12
13 23
24
25
26
27
28
29
30
31
32
33
34
35
RESERVED
ADC0*
SIM_GND
SIM_DATA
GND
RESERVED
RESERVED
RESERVED
RESERVED
TXD_AUX
RXD_AUX
GND
RESERVED
RESERVED
VDD_EXT
RESERVED
RESERVED
RI*
PSM_EINT
RXD
TXD
NETLIGHT*
RESET
SIM_VDD
VBAT_RF
POWER GND UART USIM ANT RESERVED
45
46
47
4849 50 51 52
53
54
55
56
57
58
VBAT_BB GND
14
RF_ANT
GND GND GND
RESERVED
TXD_DBG RXD_DBG
SIM_RST
SIM_CLK
RESERVED
PWRKEY
SPI_CS*
SPI_SCLK*
SPI_MOSI*
SPI_MISO*
RESERVED
GND
OTHERS
BC66
Top View
SPI
Figure 2: Pin Assignment
1. Keep all reserved pins unconnected.
2. “*”means under development.
NOTES

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3.3. Pin Description
Table 3: I/O Parameters Definition
Type
Description
IO
Bidirectional
DI
Digital input
DO
Digital output
PI
Power input
PO
Power output
AI
Analog input
AO
Analog output
Table 4: Pin Description
Power Supply
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
VBAT_BB
42
PI
Power supply for
the module’s
baseband part
Vmax=3.63V
Vmin=2.1V
Vnorm=3.3V
VBAT_RF
43
PI
Power supply for
the module’s RF
part
Vmax=3.63V
Vmin=2.1V
Vnorm=3.3V
VDD_
EXT
24
PO
1.8V output
power supply
Vnorm=1.8V
No voltage output in
PSM mode.
It is intended to supply
power for the module’s
pull-up circuits, and is
thus not recommended
to be used as the
power supply for
external circuits.
GND
1, 27, 34,
36, 37, 40,
41
GND

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Power Key Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
PWRKEY
7
DI
Pull down
PWRKEY to turn
on the module
VILmax=0.3*VBAT
VIHmin=0.7*VBAT
Reset Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
RESET
15
DI
Reset the module
Active low.
PSM_EINT Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
PSM_EINT
19
DI
Dedicated
external interrupt
pin.
Used to wake up
the module from
PSM.
Network Status Indication
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
NETLIGHT*
16
DO
Network status
indication
ADC Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
ADC0*
9
AI
General purpose
analog to digital
converter
interface
Voltage range:
0V~1.4V
Main UART Port
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
RXD
18
DI
Receive data
1.8V power domain.
TXD
17
DO
Transmit data
Auxiliary UART Port

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Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
RXD_AUX
28
DI
Receive data
1.8V power domain.
TXD_AUX
29
DO
Transmit data
Debug UART Port
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
RXD_DBG
38
DI
Receive data
1.8V power domain.
TXD_DBG
39
DO
Transmit data
Ringing Signal
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
RI*
20
DO
Ring indicator
1.8V power domain.
USIM Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
SIM_VDD
14
DO
USIM card
power supply
Vnorm=1.8V
SIM_RST
12
DO
USIM card reset
signal
VOLmax=0.15×SIM_VDD
VOHmin=0.85×SIM_VDD
SIM_DATA
11
IO
USIM card data
signal
VILmax=0.25×SIM_VDD
VIHmin=0.75×SIM_VDD
VOLmax=0.15×SIM_VDD
VOHmin=0.85×SIM_VDD
SIM_CLK
13
DO
USIM card clock
signal
VOLmax=0.15×SIM_VDD
VOHmin=0.85×SIM_VDD
SIM_GND
10
GND
Specified
ground for USIM
card
Antenna Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
RF_ANT
35
IO
RF antenna
interface
50Ωcharacteristic
impedance
SPI Interface
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment

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SPI_MISO*
3
DI
Master input
slave output of
SPI interface
1.8V power domain.
SPI_MOSI*
4
DO
Master output
slave input of SPI
interface
SPI_SCLK*
5
DO
Serial clock
signal of SPI
interface
SPI_CS*
6
DO
Chip select of
SPI interface
Reserved Pins
Pin Name
Pin No.
I/O
Description
DC Characteristics
Comment
RESERVED
2, 8,
21~23,
25~26,
30~33,
44~58
Keep these pins
unconnected.
1. Keep all unused pins unconnected.
2. “*”means under development.
3.4. Operating Modes
The following table briefly describes the three operating modes of the module.
Table 5: Overview of Operating Modes
Mode
Function
Normal Operation
Active
In active mode, all functions of the module are available and all
processors are active; radio transmission and reception can be
performed. Transitions to idle mode or PSM can be initiated in active
mode.
Idle
In idle mode, the module is in light sleep and network connection is
maintained in DRX/eDRX state; paging messages can be received.
Transitions to active mode or PSM can be initiated in idle mode.
NOTES

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3.5. Power Saving Mode (PSM)
Based on system performance, the module consumes an ultra-low current (maximally 5μA power
consumption) in PSM. PSM is designed to reduce power consumption of the module and improve battery
life. The following figure shows the power consumption of the module in different modes.
Power Consumption
PSM
Idle
Transmission
Reception
T3324 T3412 TAU
UE inactive time
Idle
Figure 3: Module Power Consumption in Different Modes
The procedure for entering PSM is as follows: the module requests to enter PSM in “ATTACH REQUEST”
message during attach/TAU (Tracking Area Update) procedure. Then the network accepts the request
and provides an active time value (T3324) to the module and the mobile reachable timer starts. When the
T3324 timer expires, the module enters PSM for duration of T3412 (periodic TAU timer). Please note that
the module cannot request PSM when it is establishing an emergency attachment or initializing the PDN
(Public Data Network) connection.
When the module is in PSM, it cannot be paged and stops access stratum activities such as cell
reselection, but T3412 is still active.
Either of the following methods can make the module exit from PSM:
After the T3412 timer expires, the module will exit PSM automatically.
Pulling down PSM_EINT (falling edge) will wake the module up from PSM. The timing of waking up
the module from PSM is illustrated below.
PSM
In PSM, only the 32kHz RTC is working, and the network is
disconnected. The module will exit from PSM and enter into active
mode when the timer T3412 times out, and it can also be woken up
from PSM by PSM_EINT. For more details, please refer to Chapter 3.5.