Microchip Technology MRF24WN0MA User manual

2015 Microchip Technology Inc. Advance Information DS50002410A-page 1
MRF24WN0MA/MB
Features
• IEEE 802.11b/g/n Compliant Transceiver
• 2.4 GHz IEEE 802.11n Single Stream 1x1
• SPI Interface to Host Controller (4-wire including
interrupt)
• Works with Microchip's MPLAB®Harmony
Integrated Software Framework
• Fully Integrated Wireless Module with Voltage
Regulation, Crystal, RF Matching Circuitry, Power
Amplifier (PA), Low Noise Amplifier (LNA), and
PCB Trace Antenna
• Ultra-Small W.FL Connector for External
Antennas (MRF24WN0MB)
• Compact Surface Mount Module: 0.700" x 1.050"
x 0.085“ (17.8 mm x 26.7 mm x 2.2 mm)
• Castellated Surface Mount Pads for easy and
reliable PCB mounting
• Environmentally Friendly, RoHS Compliant
Operational
• Single Operating Voltage: 3.15V to 3.45V (3.3V
typical)
• Temperature Range: -40°C to +85°C Industrial
• Low-Current Consumption:
- RX mode: 64 mA (typical)
- TX mode: 246 mA at 18 dBm (typical)
• Power Saving Mode:
- Hibernate: 10 µA (typical)
RF/Analog
• Frequency: 2.412 to 2.472 GHz
• Channels: 1-13
• Modulation: DSSS, CCK, BPSK, QPSK, 16QAM,
64QAM
• Sensitivity: -94 dBm
Antenna
• Integral PCB Trace Antenna (MRF24WN0MA)
• External Antenna (MRF24WN0MB)
Compliance
• Modular Certified for the United States (FCC) and
Canada (IC)
• European R&TTE Directive Assessed Radio
Module
• Australia, New Zealand, Korea, Taiwan, and
Japan
Applications
• Utility and Smart Energy
• Consumer Electronics
• Industrial Controls
• Remote Device Management
• Retail
• Medical, Fitness, and Health Care
2.4 GHz IEEE 802.11b/g/n Wireless Module

MRF24WN0MA/MB
DS50002410A-page 2 Advance Information 2015 Microchip Technology Inc.
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 3
2.0 Circuit Description .......................................................................................................................................................................11
3.0 Application Information............................................................................................................................................................... 15
4.0 Regulatory Approval ................................................................................................................................................................... 21
5.0 Electrical Characteristics ............................................................................................................................................................ 27
Appendix A: Revision History............................................................................................................................................................... 29
The Microchip Web Site ....................................................................................................................................................................... 31
Customer Change Notification Service ................................................................................................................................................ 31
Customer Support ................................................................................................................................................................................ 31
Product Identification System............................................................................................................................................................... 33
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2015 Microchip Technology Inc. Advance Information DS50002410A-page 3
MRF24WN0MA/MB
1.0 DEVICE OVERVIEW
The MRF24WN0MA and MRF24WN0MB are low-
power, 2.4 GHz, IEEE 802.11n compliant, surface
mount modules containing all associated RF
components: crystal oscillator, bypass and bias
passives with integrated MAC, baseband, RF and
power amplifier, and built-in hardware support for
encryption. Refer to Figure 1-1.
The integrated module design frees the designer from
RF and antenna design tasks and regulatory
compliance testing, ultimately providing faster time to
market.
The MRF24WN0MA/MB modules are designed to be
used with Microchip's MPLAB® Harmony Integrated
Software Framework. The integrated framework imple-
ments the Application Programming Interface (API)
that is used for command and control, management
and data packet traffic.
The MPLAB Harmony basic framework is available via
a free download from the Microchip web site at
http://www.microchip.com/harmony. For more informa-
tion on the basic framework and available release ver-
sions, refer to “MPLAB®Harmony Release Notes and
Contents” found under the Documentation tab.
The MRF24WN0MA module is approved for use with
the integrated PCB trace antenna. The MRF24WN0MB
module is approved for use with specific external
antenna types that are certified with the module. An
ultra-small coaxial connector (W.FL) is provided on the
module for connection to the external antenna. Refer to
Section 3.3, "External Antenna Types" for a listing of
approved antenna types.
The MRF24WN0MA/MB modules received the regula-
tory approvals for modular devices in the United States
(FCC) and Canada (IC). Modular approval removes the
need for expensive RF and antenna design, and
enables the end user to place the MRF24WN0MA/MB
modules inside a finished product without requiring a
regulatory testing for an intentional radiator (RF trans-
mitter).
The MRF24WN0MA/MB module is an R&TTE Directive
assessed radio module for operation in Europe. The
module tests can be applied toward final product
certification and Declaration of Conformity (DoC).
Table 1-1 lists the MFR24WN0 module’s family types.
FIGURE 1-1: MRF24WN0MA/MB BLOCK DIAGRAM
TABLE 1-1: MRF24WN0 FAMILY TYPES
Device Antenna
MRF24WN0MA Integral
MRF24WN0MB External
Matching
Circuitry
Wi-Fi
SoC
Flash
PCB Trace
Antenna
(MRF24WN0MA)
External Antenna
Connector
(MRF24WN0MB)
Power
MRF24WN0MA/MB 2.4 GHz IEEE 802.11 b/g/n Module
SPI
Hibernate
Interrupt

MRF24WN0MA/MB
DS50002410A-page 4 Advance Information 2015 Microchip Technology Inc.
1.1 Interface Description
Figure 1-2 shows the MRF24WN0MA/MB pin diagram. Ta bl e 1- 2 describes the MRF24WN0MA/MB pins.
FIGURE 1-2: MRF24WN0MA/MB PIN DIAGRAM
37 GNDGND 1
TEST 2
GND 3
VDD 4
NC 5
NC 6
NC 7
NC 8
NC 9
NC 10
NC 11
NC 12
SPI_CLK 13
SPI_MISO 14
36 GND
35 VDD
34 GND
33 NC
32 NC
31 NC
30 NC
29 NC
28 NC
27 GND
26 NC
25 NC
24 GND
VDD 15
GND 16
TEST 17 TEST 18
HIBERNATE 19
SPI_INT 20
MODE0 21
SPI_MOSI 22
SPI_CS/MODE1 23

2015 Microchip Technology Inc. Advance Information DS50002410A-page 5
MRF24WN0MA/MB
TABLE 1-2: PIN DESCRIPTIONS
Pin Name Type Description(1)
1GND Power —
2 TEST Test Do not connect
3GND Power —
4 VDD Power —
5 NC Reserved Do not connect
6 NC Reserved Do not connect
7 NC Reserved Do not connect
8 NC Reserved Do not connect
9 NC Reserved Do not connect
10 NC Reserved Do not connect
11 NC Reserved Do not connect
12 NC Reserved Do not connect
13 SPI_CLK DI SPI clock input
14 SPI_MISO DO SPI data output; pull-down to GND with 10 kilo-ohm
resistor
15 VDD Power —
16 GND Power —
17 TEST Test Do not connect
18 TEST Test Do not connect
19 HIBERNATE DI Lowest Power State (active-low)
20 SPI_INT DO SPI interrupt output (active-low)
21 MODE0 DI Mode select 0; Connect to GND(2)
22 SPI_MOSI DI SPI data input
23 SPI_CS/MODE1 DI SPI Chip Select/Mode select 1; Connect to VDD via
10 kilo-ohm pull-up resistor(2)(3)
24 GND Power —
25 NC Reserved Do not connect
26 NC Reserved Do not connect
27 GND Power —
28 NC Reserved Do not connect
29 NC Reserved Do not connect
30 NC Reserved Do not connect
31 NC Reserved Do not connect
32 NC Reserved Do not connect
33 NC Reserved Do not connect
34 GND Power —
35 VDD Power —
36 GND Power —
37 GND Power —
Legend: A = Analog, D = Digital, I = Input, O = Output
Note 1: For NC = No Connect pins, do not make any connection. The module is configured with internal pull-up
and pull-down resistors.
2: Refer to Section 2.2, "MODE0 and MODE1 Pins"
3: Refer to Section 2.3, "SPI Port Pins"

MRF24WN0MA/MB
DS50002410A-page 6 Advance Information 2015 Microchip Technology Inc.
1.2 Mounting Details
Figure 1-3, Figure 1-4 and Figure 1-5 show the physical dimensions and the mounting details of the module.
Figure 1-6 and Figure 1-7 show the recommended host PCB footprint and layout.
FIGURE 1-3: MRF24WN0MA/MB MODULE PHYSICAL DIMENSIONS (TOP AND SIDE VIEW)
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2015 Microchip Technology Inc. Advance Information DS50002410A-page 7
MRF24WN0MA/MB
FIGURE 1-4: MRF24WN0MA/MB MODULE PHYSICAL DIMENSIONS (BOTTOM VIEW)
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MRF24WN0MA/MB
DS50002410A-page 8 Advance Information 2015 Microchip Technology Inc.
FIGURE 1-5: MRF24WN0MA/MB MODULE MOUNTING DETAILS
Keep area around antenna
(approximately 1.25 inches) clear
of metallic structures for
best performance.
1.25
1.25
Edge of
Host PCB
Ground Plane
0.2550.795
(Top View)
Dimensions are in inches

2015 Microchip Technology Inc. Advance Information DS50002410A-page 9
MRF24WN0MA/MB
FIGURE 1-6: MRF24WN0MA/MB RECOMMENDED HOST PCB FOOTPRINT
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MRF24WN0MA/MB
DS50002410A-page 10 Advance Information 2015 Microchip Technology Inc.
FIGURE 1-7: MRF24WN0MA/MB HOST PCB EXAMPLE LAYOUT
1.3 Soldering Recommendations
The MRF24WN0MA/MB wireless module was assem-
bled using the IPC/JEDEC J-STD-020 Standard lead-
free reflow profile. The MRF24WN0MA/MB module
can be soldered to the host PCB using standard leaded
and lead-free solder reflow profiles.
To avoid damaging the module, adhere to the following
recommendations:
• Solder reflow recommendations are provided in
the Microchip Application Note, AN233 "Solder
Reflow Recommendation" (DS00233)
• Do not exceed a peak temperature (TP) of 250°C
• Refer to the solder paste data sheet for specific
reflow profile recommendations from the vendor
• Use no-clean flux solder paste
• Do not wash as moisture can be trapped under
the shield
• Use only one flow. If the PCB requires multiple
flows, apply the module on the final flow.
Best
Okay Okay
Okay
No Copper
in these Areas

2015 Microchip Technology Inc. Advance Information DS50002410A-page 11
MRF24WN0MA/MB
2.0 CIRCUIT DESCRIPTION
2.1 Overview
The MRF24WN0MA/MB module interfaces to the
PIC32 MCU via a 4-wire SPI port, Interrupt and Hiber-
nate pins as illustrated in Figure 2-1. The
MRF24WN0MA/MB modules are designed to work
with Microchip's MPLAB®Harmony Integrated Soft-
ware Framework. The integrated framework imple-
ments the Application Programming Interface (API)
that is used for command and control, management
and data packet traffic.
The MPLAB Harmony basic framework is available via
a free download from the Microchip web site at
http://www.microchip.com/harmony. For more informa-
tion on the basic framework and available release ver-
sions, refer to the “MPLAB Harmony Release Notes
and Contents” found under the Documentation tab.
If you are new to the MPLAB Harmony framework, visit
http://www.microchip.com/harmony and go to the
Training > Getting Started tab.
The MPLAB Harmony Help document is available for
download from the MPLAB Harmony framework direc-
tory: c:\microchip\harmony\<version>\doc.
The PIC32 input/output ports (SPI, Interrupt and Hiber-
nate) are configured in the MPLAB Harmony frame-
work configuration files as described in the MPLAB
Harmony Help document.
2.2 MODE0 and MODE1 Pins
The MODE pins must be tied to the voltage levels for
normal operation of the module. Refer to Table 2-1.
The MODE pins are sampled at power on and wake-
up. Refer to Section 2.6, "Hibernate". In the case of
SPI_CS/MODE1 pin, pull-up using a 10 kresistor and
the host MCU allows an active-high signal during
power on and wake-up to ensure that the module start-
up in normal operation. Once the module is
operational, the pin becomes the SPI Port Chip Select
pin (active-low).
FIGURE 2-1: HARMONY TO MRF24WN0MA/MB BLOCK DIAGRAM
TABLE 2-1: MODE PIN OPERATION
Pin Condition
MODE0 Connect to GND
SPI_CS/MODE1 Connect to VDD via 10 k
pull-up resistor
Hibernate
Interrupt
Application(s)
TCP/IP Stack
Wi-Fi Driver
PLIB
PIC32
SPI
MRF24WN0MA/MB
Power
Ground

MRF24WN0MA/MB
DS50002410A-page 12 Advance Information 2015 Microchip Technology Inc.
2.3 SPI Port Pins
The MRF24WN0MA/MB module interfaces to the
PIC32 MCU via a 4-wire SPI port. Refer to Figure 2-2
and Tab le 2 - 2 for the necessary signaling conditions.
In the case of the SPI_CS/MODE1 pin, pull-up using a
10 kresistor and the host MCU allows an active-high
signal during power on and wake-up to ensure that the
module start-up in normal operation. Once the module
is operational, the pin becomes the SPI Port Chip
Select pin (active-low).
FIGURE 2-2: SPI SLAVE INTERFACE TIMING
TABLE 2-2: SPI SLAVE TIMING CONSTRAINTS
Parameter Description Min. Max. Unit
fPP Clock Frequency 0 48 MHz
tWL Clock Low Time 8.3 — ns
tWH Clock High Time 8.3 — ns
tTLH Clock Rise Time — 2 ns
tTHL Clock Fall Time — 2 ns
tISU Input Setup Time 5 — ns
tIH Input Hold Time 5 — ns
tO_DLY Output Delay 0 5 ns
Clock
MOSI
MISO
VIH
VIL
VIH
VIL
VOH
VOL
fPP
tWL
tWH
tTLH tTHL
tISU tIH
tO_DLY(max) tO_DLY(min)

2015 Microchip Technology Inc. Advance Information DS50002410A-page 13
MRF24WN0MA/MB
2.4 Interrupt Pin
The SPI_INT line works in conjunction with the SPI
port. It is an active-low output signal to the host MCU to
signal an interrupt event.
2.5 VDD and GND Pin
The MRF24WN0MA/MB wireless module contains an
integrated power management unit that generates all
necessary voltages required by the internal circuitry.
The module is powered from a single voltage source.
Table 2-3 lists the recommended bypass capacitors.
The capacitors must be closely placed to the module.
2.6 Hibernate
The module enters the lowest power mode when the
HIBERNATE pin is asserted low. No state information
is preserved. The MPLAB Harmony framework can
save state information in the host MCU that can be
restored after wake-up (HIBERNATE pin is asserted
high).
The module can wake-up when HIBERNATE pin is
asserted high. The module must be initialized and any
state information saved prior to Hibernate state is
restored. This process approximately takes 40 ms.
TABLE 2-3: RECOMMENDED BYPASS
CAPACITORS
Pin Symbol Bypass Capacitors
4 VDD 0.1 µF and 2.2 µF
15 VDD 0.1 µF and 2.2 µF
35 VDD 0.1 µF and 2.2 µF

MRF24WN0MA/MB
DS50002410A-page 14 Advance Information 2015 Microchip Technology Inc.
NOTES:

2015 Microchip Technology Inc. Advance Information DS50002410A-page 15
MRF24WN0MA/MB
3.0 APPLICATION INFORMATION
This section provides information on the Application Schematic, Integral PCB Trace Antenna, and Antenna Types.
3.1 Application Schematic
Figure 3-1 shows the schematic for the MRF24WN0MA module.
FIGURE 3-1: APPLICATION SCHEMATIC
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MRF24WN0MA/MB
DS50002410A-page 16 Advance Information 2015 Microchip Technology Inc.
3.2 Integral PCB Trace Antenna
For the MRF24WN0MA, the PCB antenna is fabricated
on the top copper layer and covered in solder mask.
The layers below the antenna do not have copper
trace.
It is recommended that the module is mounted on the
edge of the host PCB. It is permitted for PCB material
to be below the antenna structure of the module as long
as no copper traces or planes are on the host PCB in
that area. For best performance, place the module on
the host PCB according to the details shown in
Figure 1-6.
The antenna patterns plotted in Figure 3-2 through
Figure 3-5 are the simulated results of the PCB
antenna.
Figure 3-2 illustrates the simulation drawing. The two-
dimensional (2D) radiation pattern is illustrated in
Figure 3-3, whereas Figure 3-4 and Figure 3-5 shows
the three-dimensional (3D) radiation patterns.
The calculated average of the radiated field is shown in
Figure 3-3. The radiation pattern for the XZ plane is
shown in red, whereas the YZ plane is shown in violet.
The most powerful radiation occurs in the XZ plane as
represented by the red pattern.
Figure 3-4 shows the relative position of the 3D radia-
tion “donut” with reference to the module orientation.
This is a very useful guide for placement of the module
to obtain the maximum range.
Figure 3-5 shows the 3D radiation pattern with the col-
ored distribution of the radiation magnitude. The values
range from -9 dB to +0.3 dB. This is very useful in inter-
preting the 2D radiation pattern.
FIGURE 3-2: PCB ANTENNA SIMULATION DRAWING

2015 Microchip Technology Inc. Advance Information DS50002410A-page 17
MRF24WN0MA/MB
FIGURE 3-3: SIMULATED TWO-DIMENSIONAL RADIATION PATTERN
Name Theta Angle Mag. Curve Information Average
m1 -60.0000 -60.0000 0.6323 dB (Gain Total)
Setup 1: Last Adaptive
Freq. = “2.44 GHz” Phi = “0 deg”
0.0097
m2 -20.0000 -20.0000 0.3962
m3 30.0000 30.0000 -0.1038
m4 100.0000 100.0000 -0.9490 dB (Gain Total)
Setup 2: Last Adaptive
Freq. = “2.44 GHz” Phi = “0 deg”
-3.2020
m5 170.0000 170.0000 -0.1414
Radiation Pattern 1
Two-dimensional (2D) pattern, including the average on main radiation planes (Phi = 0 and 90 degrees).

MRF24WN0MA/MB
DS50002410A-page 18 Advance Information 2015 Microchip Technology Inc.
FIGURE 3-4: SIMULATED THREE-DIMENSIONAL RADIATION PATTERN
Radiation pattern against the module dimensions

2015 Microchip Technology Inc. Advance Information DS50002410A-page 19
MRF24WN0MA/MB
FIGURE 3-5: SIMULATED THREE-DIMENSIONAL RADIATION PATTERN
Three-dimensional (3D) pattern and magnitude distribution

MRF24WN0MA/MB
DS50002410A-page 20 Advance Information 2015 Microchip Technology Inc.
3.3 External Antenna Types
The MRF24WN0MB module has an ultra-small coaxial
connector (W.FL) for connection to the external
antenna.
The choice of antenna is limited to the antenna types in
which the module is tested and approved. For a list of
tested and approved antenna types that may be used
with the module, refer to the respective country in
Section 4.0, Regulatory Approval.
Table 3-1 lists the approved antennas types.
TABLE 3-1: TESTED EXTERNAL
ANTENNA TYPES
Type Gain
PCB Trace 1 dBi
Dipole 2 dBi
PIFA -3 dBi