RF-Star RF-BM-4044B2 User manual

RF-BM-4044B2 and RF-BM-4044B3
CC2640R2FRSM
Bluetooth 5.1 Low Energy Module
Version 1.1
Shenzhen RF-star Technology Co., Ltd.
May 26th, 2023
All rights reserved. Those responsible for unauthorized reproduction will be prosecuted.

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1 Device Overview
1.1 Module Series
There is a series of RF-BM-4044Bx Bluetooth 5.1 Low Energy modules. All of them are based on TI CC2640R2FRSM
SoC.
Table 1. Module Series of RF-BM-4044Bx
Model
Dimension
Antenna Output Mode
Chip Model
4044B2
16.6 mm x 11.2 mm x 1.7 mm
PCB onboard antenna
CC2640R2FRSM
4044B3
15.2 mm x 11.2 mm x 2.1 mm
IPEX connector
1.2 Description
RF-BM-4044B2 and RF-BM-4044B3 modules are designed based on CC2640R2FRSM System-on-Chip, which fully
supports the single-mode Bluetooth 5.1 Low Energy operation. The module contains a 32-bit ARM Cortex-M3 processor,
with a working frequency of 48.0 MHz. The module has rich peripherals function libraries, and a unique ultra-low power
sensor controller, which is fit for connecting the external sensors in sleep mode or acquiring analog and digital data
independently. RF-BM-4044B2 is pin-compatible with RF-BM-4044B3. 4044B2 is the high-performance onboard PCB
antenna and the 4044B3 is equipped with an IPEX connector for the feasible external antennas.
1.3 Key Features
•RF Features
- Bluetooth low energy 5.1
- Bluetooth Long Range
- Data rate: 1 Mbps, 2 Mbps, 125 kbps, 500
kbps
•TX power: -21 dBm ~ +2 dBm
•RF sensitivity
- -97 dBm @ 1 Mbps
- -92 dBm @ 2 Mbps
- -103 dBm @ 125 kbps (LE Coded)
- -101 dBm @ 500 kbps (LE Coded)
•Differential RF interface
•Microcontroller
- Powerful 48 MHz ARM® Cortex®-M3
- EEMBC CoreMark® Score: 142
- 2-pin cJTAG and JTAG debugging
- Supports over-the-air upgrade (OTA)
•Memory
- 128 KB of in-system programmable flash
- Up to 28 KB of system SRAM, of which 20 KB
is ultra-low leakage SRAM
- 8 KB of SRAM for cache or system RAM use
•Ultra-low power sensor controller
- 16-bit architecture
- 2 KB of ultra-low leakage SRAM for code and
data
•Rich Peripherals
- All digital peripheral pins can be routed to any
GPIO
- 10 GPIOs
- Four general-purpose Timer modules(eight
16-bit or four 32-bit Timers, PWM each)
- 12-bit ADC, 200 ksamples/s, 8-channel
analog MUX
- Continuous time comparator
- Ultra-low-power analog comparator

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- Programmable current source
- UART
- 2 × SSI (SPI, MICROWIRE, TI)
- I2C
- I2S
- Real-time clock (RTC)
- AES-128 security module
- True random number generator (TRNG)
•Dimension
- RF-BM-4044B2: 16.6 mm x 11.2 mm x 1.7
mm
- RF-BM-4044B3: 15.2 mm x 11.2 mm x 2.1
mm
•Certificate
- RF-BM-4044B2
➢FCC
➢SRRC
➢RoHS
1.4 Applications
•Smart toys
•Fitness equipment
•Environmental sensor nodes
•Passive key-less entry (PKE)
•Smart door locks
•Phone accessories
•Health-care equipment
•Smart lighting
•Energy harvesting
•Thermometer
•Human input devices
•Sports equipment
1.5 Functional Block Diagram
Figure 1. Functional Block Diagram of RF-BM-4044B2/4044B3
CC2640
R2F
GPIO
Power EMI
Filter
24.0 MHz
32.768 kHz
Reset
LC Balun
B2: PCB Antenna
B3: IPEX connector
RF-N
RF-P
Low Pass
Filter & ANT
Matching
Power Supply
1.8 V ~ 3.8 V

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1.6 Part Number Conventions
The part numbers are of the form of RF-BM-4044B2/4044B3 where the fields are defined as follows:
Figure 2. Part Number Conventions of RF-BM-4044B2/4044B3
RF
BM
4044
Company Name
RF-STAR
Wireless Type
Bluetooth Module
Chipset
TI CC2640R2FRSM
-
-
B2
Module Version
B2: The Second Version(PCB)
B3: The Third Version(IPEX)

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Table of Contents
1 Device Overview............................................................................................................................................................. 1
1.1 Module Series ..................................................................................................................................................... 1
1.2 Description............................................................................................................................................................ 1
1.3 Key Features ....................................................................................................................................................... 1
1.4 Applications.......................................................................................................................................................... 2
1.5 Functional Block Diagram .............................................................................................................................. 2
1.6 Part Number Conventions.............................................................................................................................. 3
Table of Contents................................................................................................................................................................ 4
2 Module Configuration and Functions ...................................................................................................................... 6
2.1 Module Parameters........................................................................................................................................... 6
2.2 Module Pin Diagram ......................................................................................................................................... 7
2.3 Pin Functions....................................................................................................................................................... 7
3 Specifications ................................................................................................................................................................... 9
3.1 Recommended Operating Conditions ....................................................................................................... 9
3.2 Handling Ratings................................................................................................................................................ 9
3.3 RF Test................................................................................................................................................................... 9
4 Application, Implementation, and Layout.............................................................................................................10
4.1 Module Photos..................................................................................................................................................10
4.2 Recommended PCB Footprint....................................................................................................................10
4.3 Schematic Diagram.........................................................................................................................................11
4.4 Reference Design............................................................................................................................................12
4.5 Antenna................................................................................................................................................................12
4.5.1 Antenna Design Recommendation ..............................................................................................12
5.4.2 External Antenna Design Recommendation of the Half-Hole ANT Pin..........................13
5.4.3 IPEX Connector Specification........................................................................................................14
4.6 Basic Operation of Hardware Design ......................................................................................................15
4.7 Trouble Shooting..............................................................................................................................................16
4.7.1 Unsatisfactory Transmission Distance........................................................................................16
4.7.2 Vulnerable Module..............................................................................................................................16
4.7.3 High Bit Error Rate .............................................................................................................................16
4.8 Electrostatics Discharge Warnings ...........................................................................................................17

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4.9 Soldering and Reflow Condition.................................................................................................................17
5 Optional Package Specification ..............................................................................................................................19
6 Certification .....................................................................................................................................................................21
6.1 FCC.......................................................................................................................................................................21
6.2 RoHS ....................................................................................................................................................................21
6.3 SRRC ...................................................................................................................................................................22
7 Revision History ............................................................................................................................................................23
8 Contact Us.......................................................................................................................................................................24

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2 Module Configuration and Functions
2.1 Module Parameters
Table 2. Parameters of RF-BM-4044B2/4044B3
Chipset
CC2640R2FRSM
Supply Power Voltage
1.8 V ~ 3.8 V, recommended to 3.3 V
Frequency
2402 MHz ~ 2480 MHz
Transmit Power
-21.0 dBm ~ +2.0 dBm (typical: 0 dBm)
Receiving Sensitivity
-97 dBm @ 1 Mbps
-92 dBm @ 2 Mbps
-103 dBm @ 125 kbps (LE Coded)
-101 dBm @ 500 kbps (LE Coded)
GPIO
10
Crystal
24 MHz, 32.768 kHz
RAM
20 KB
Flash
128 KB
Package
SMT Packaging (1.27-mm half-hole pitch stamp stick)
Frequency Error
±20 kHz
Dimension
RF-BM-4044B2: 16.6 mm x 11.2 mm x 1.7 mm
RF-BM-4044B3: 15.2 mm x 11.2 mm x 2.1 mm
Type of Antenna
RF-BM-4044B2: PCB antenna
RF-BM-4044B3: IPEX connector
Operating Temperature
-40 ℃～+85 ℃
Storage Temperature
-40 ℃～+125 ℃

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2.2 Module Pin Diagram
RF-BM-4044B2 RF-BM-4044B3
Figure 3. Pin Diagram of RF-BM-4044B2/4044B3
2.3 Pin Functions
Table 3. Pin Functions of RF-BM-4044B2/4044B3
Pin
Name
Chip Pin
Pin Type
Description
1
GND
GND
GND
GND
2
VDDZ
VCC
Power
Power supply 1.8 V ~ 3.8 V, recommend 3.3 V
3
TMSC
JTAG_TMSC
Digital I/O
JTAG TMSC
4
TCKC
JTAG_TCKC
Digital I/O
JTAG TCKC
5
RES_N
RESET
RESET
Reset, active low.
6
P06
DIO_6
Digital/Analog I/O
GPIO, Sensor Controller, Analog
7
P09
DIO_9
Digital/Analog I/O
GPIO, Sensor Controller, Analog
8
GND
GND
GND
Ground
9
GND
GND
GND
Ground
10
P08
DIO_8
Digital/Analog I/O
GPIO, Sensor Controller, Analog
11
P07
DIO_7
Digital/Analog I/O
GPIO, Sensor Controller, Analog
12
P05
DIO_5
Digital/Analog I/O
GPIO, Sensor Controller, Analog
13
P04
DIO_4
Digital I/O
GPIO, Sensor Controller, JTAG_TDI
14
P03
DIO_3
Digital I/O
GPIO, Sensor Controller, JTAG_TDO

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15
P02
DIO_2
Digital I/O
GPIO, Sensor Controller, high-drive capacity
16
P01
DIO_1
Digital I/O
GPIO, Sensor Controller, high-drive capacity
17
P00
DIO_0
Digital I/O
GPIO, Sensor Controller, high-drive capacity
18
NC
-
-

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3 Specifications
3.1 Recommended Operating Conditions
Functional operation does not guarantee performance beyond the limits of the conditional parameter values in the table
below. Long-term work beyond this limit will affect the reliability of the module more or less.
Table 4. Recommended Operating Conditions of RF-BM-4044B2/4044B3
Items
Condition
Min.
Typ.
Max.
Unit
Operating Supply Voltage
Battery Mode
1.8
3.3
3.8
V
Operating Temperature
/
-40
+25
+85
℃
Environmental Hot Pendulum
/
-20
+20
℃/min
3.2 Handling Ratings
Table 5. Handling Ratings of RF-BM-4044B2/4044B3
Items
Condition
Min.
Typ.
Max.
Unit
Storage Temperature
Tstg
-40
+25
+125
℃
Human Body Model
HBM
±2500
V
Moisture Sensitivity Level
3
Charged Device Model
±750
V
3.3 RF Test
When measured on the RF-BM-4044B2 reference design with T A = 25 ℃, V BAT = 3.3 V with DC/DC, the channel of
39th (2442 MHz) enabled unless otherwise noted.
Table 6. Table of RF Test
Test Item
Parameter
Test Value
Unit
Transmitter
Power
2 (Max.)
dBm
Frequency Error
±20
kHz
Radiation (30 m ~ 1 G)
-36
dBm
Radiation (1 G ~ 12.75 G)
-30
dBm
Receiver
Sensitivity (8% PER)
-93
dBm

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4 Application, Implementation, and Layout
4.1 Module Photos
RF-BM-4044B2 RF-BM-4044B3
Figure 4. Photos of RF-BM-4044B2/4044B3
4.2 Recommended PCB Footprint
RF-BM-4044B2

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RF-BM-4044B3
Figure 5. Recommended PCB Footprint of RF-BM-4044B2/4044B3 (mm)
4.3 Schematic Diagram
Figure 6. Schematic Diagram of RF-BM-4044B2/4044B3

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4.4 Reference Design
Note: EN low enable.
Figure 7. Reference Design of RF-BM-4044B2/4044B3
4.5 Antenna
4.5.1 Antenna Design Recommendation
1. The antenna installation structure has a great influence on the module performance. It is necessary to ensure the
antenna is exposed and preferably vertically upward. When the module is installed inside of the case, a high-quality
antenna extension wire can be used to extend the antenna to the outside of the case.
2. The antenna must not be installed inside the metal case, which will cause the transmission distance to be greatly
weakened.
3. The recommendation of antenna layout.
The inverted-F antenna position on PCB is free-space electromagnetic radiation. The location and layout of the
antenna are key factors to increase the data rate and transmission range.
Therefore, the layout of the module antenna location and routing is recommended as follows:
1. Place the antenna on the edge (corner) of the PCB.
2. Make sure that there is no signal line or copper foil in each layer below the antenna.
3. It is best to hollow out the antenna position in the following figure to ensure that the S11 of the module is
minimally affected.

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Figure 8. Recommendation of Antenna Layout
Note: The hollow-out position is based on the antenna used.
5.4.2 External Antenna Design Recommendation of the Half-Hole ANT Pin
1. A Π-type matching circuit is reserved for the antenna, and 50 Ω impedance control is performed on the RF traces.
The traces are as short as possible, and 135° or arc traces are used as much as possible. No vias are used to
change layers. More GND vias are placed around the RF traces.
Figure 9. Reference Design of the External Antenna
Figure 10. Reference Design of the External Antenna Traces

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2. The RF trace width and copper-clad spacing can be calculated by SI9000 software, and the impedance is controlled
to 50 Ω according to the actual board thickness, number of layers, plate, dielectric thickness, dielectric constant,
copper thickness, line width, line spacing, and solder mask thickness.
Example: FR4 is a double-layer board with a thickness of 1.0 mm. Through calculation, the width of the trace is
0.8254 mm, and the spacing between traces and copper is 0.22 mm.
Figure 11. SI9000 Impedance Calculation Diagram
5.4.3 IPEX Connector Specification
RF-BM-4044B3 module is integrated the IPEX version 1 antenna seat, the specification of the antenna seat is as follows:
Figure 12. Specification of Antenna Seat

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The specification of the IPEX wire end is as follows:
Figure 13. Specification of IPEX Wire
4.6 Basic Operation of Hardware Design
1. It is recommended to offer the module a DC stabilized power supply, a tiny power supply ripple coefficient, and
reliable ground. Please pay attention to the correct connection between the positive and negative poles of the power
supply. Otherwise, the reverse connection may cause permanent damage to the module;
2. Please ensure the supply voltage is between the recommended values. The module will be permanently damaged
if the voltage exceeds the maximum value. Please ensure a stable power supply and no frequently fluctuating
voltage.
3. When designing the power supply circuit for the module, it is recommended to reserve more than 30% of the margin,
which is beneficial to the long-term stable operation of the whole machine. The module should be far away from the
power electromagnetic, transformer, high-frequency wiring, and other parts with large electromagnetic interference.
4. The bottom of the module should avoid high-frequency digital routing, high-frequency analog routing, and power
routing. If it has to route the wire on the bottom of the module, for example, it is assumed that the module is soldered
to the Top Layer, the copper must be spread on the connection part of the top layer and the module, and be close
to the digital part of the module and routed in the Bottom Layer (all copper is well-grounded).
5. Assuming that the module is soldered or placed in the Top Layer, it is also wrong to randomly route the Bottom Layer
or other layers, which will affect the spurs and receiving sensitivity of the module to some degree;
6. Assuming that there are devices with large electromagnetic interference around the module, which will greatly affect
the module performance. It is recommended to stay away from the module according to the strength of the
interference. If circumstances permit, appropriate isolation and shielding can be done.

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7. Assuming that there are routings of large electromagnetic interference around the module (high-frequency digital,
high-frequency analog, power routings), which will also greatly affect the module performance. It is recommended
to stay away from the module according to the strength of the interference. If circumstances permit, appropriate
isolation and shielding can be done.
8. It is recommended to stay away from the devices whose TTL protocol is the same 2.4 GHz physical layer, for
example, USB 3.0.
4.7 Trouble Shooting
4.7.1 Unsatisfactory Transmission Distance
1. When there is a linear communication obstacle, the communication distance will be correspondingly weakened.
Temperature, humidity, and co-channel interference will lead to an increase in the communication packet loss rate.
The performance of ground absorption and reflection of radio waves will be poor when the module is tested close to
the ground.
2. Seawater has a strong ability to absorb radio waves, so the test results by the seaside are poor.
3. The signal attenuation will be very obvious if there is metal near the antenna or if the module is placed inside the
metal shell.
4. The incorrect power register set or the high data rate in the open air may shorten the communication distance. The
higher the data rate, the closer the distance.
5. The low voltage of the power supply is lower than the recommended value at ambient temperature, and the lower
the voltage, the smaller the power is.
6. The unmatchable antennas and modules or the poor quality of the antenna will affect the communication distance.
4.7.2 Vulnerable Module
1. Please ensure the supply voltage is between the recommended values. The module will be permanently damaged
if the voltage exceeds the maximum value. Please ensure a stable power supply and no frequently fluctuating
voltage.
2. Please ensure the anti-static installation and the electrostatic sensitivity of high-frequency devices.
3. Due to some humidity-sensitive components, please ensure suitable humidity during installation and application. If
there is no special demand, it is not recommended to use at too high or too low temperature.
4.7.3 High Bit Error Rate
1. There are co-channel signal interferences nearby. It is recommended to be away from the interference sources or
modify the frequency and channel to avoid interferences.
2. The unsatisfactory power supply may also cause garbled. It is necessary to ensure the power supply's reliability.

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3. If the extension wire or feeder wire is of poor quality or too long, the bit error rate will be high.
4.8 Electrostatics Discharge Warnings
The module will be damaged by the discharge of static. RF-star suggests that all modules should follow the 3 precautions
below:
1. According to the anti-static measures, bare hands are not allowed to touch modules.
2. Modules must be placed in anti-static areas.
3. Take the anti-static circuitry (when inputting HV or VHF) into consideration in product design.
Static may result in the degradation in performance of the module, even causing failure.
4.9 Soldering and Reflow Condition
1. Heating method: Conventional Convection or IR/convection.
2. Solder paste composition: Sn96.5/Ag3.0/Cu0.5
3. Allowable reflow soldering times: 2 times based on the following reflow soldering profile.
4. Temperature profile: Reflow soldering shall be done according to the following temperature profile.
5. Peak temperature: 245 ℃.
Table 7. Temperature Table of Soldering and Reflow
Profile Feature
Sn-Pb Assembly
Pb-Free Assembly
Solder Paste
Sn63 / Pb37
Sn96.5 / Ag3.0 / Cu0.5
Min. Preheating Temperature (Tmin)
100 ℃
150 ℃
Max. Preheating Temperature (Tmax)
150 ℃
200 ℃
Preheating Time (Tmin to Tmax) (t1)
60 s ~ 120 s
60 s ~ 120 s
Average Ascend Rate (Tmax to Tp)
Max. 3 ℃/s
Max. 3 ℃/s
Liquid Temperature (TL)
183 ℃
217 ℃
Time above Liquidus (tL)
60 s ~ 90 s
30 s ~ 90 s
Peak Temperature (Tp)
220 ℃ ~ 235 ℃
230 ℃ ~ 250 ℃
Average Descend Rate (Tpto Tmax)
Max. 6 ℃/s
Max. 6 ℃/s
Time from 25 ℃ to Peak Temperature (t2)
Max. 6 minutes
Max. 8 minutes
Time of Soldering Zone (tP)
20±10 s
20±10 s

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Figure 14. Recommended Reflow for Lead-Free Solder

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5 Optional Package Specification
The default package method is by tray. If you need the modules to be shipped by tape & reel, pls contact us in advance.
Figure 15. Default Package by Tray