MRF24WG0MA_12 Datasheet, PDF (5/38 Pages) Microchip Technology – MRF24WG0MA/MB Data Sheet 2.4 GHz IEEE 802.11b/g™

1.0 DEVICE OVERVIEW
The MRF24WG0MA and MRF24WG0MB are low-
power, 2.4 GHz, IEEE 802.11-compliant, surface
mount modules with all associated RF components –
crystal oscillator, bypass and bias passives with inte-
grated MAC, baseband, RF and power amplifier, and
built-in hardware support for AES, and TKIP (WEP,
WPA, WPA2 security). The modules also provide
acceleration for hosts running WPA-EAP application
security. The integrated module design frees the
designer from RF and antenna design tasks and regu-
latory compliance testing, ultimately providing quicker
time to market.
The MRF24WG0MA module is approved for use with
the integrated PCB meander antenna.
The MRF24WG0MB module comes with an ultra-
miniature coaxial connector (U.FL) and is approved
for use with a list of antenna types that are certified
with the module. See Section 2.7 “External
Antenna” for specific recommendations.
The MRF24WG0MA/MB modules are designed to be
used with Microchip’s TCP/IP software stack. The soft-
ware stack has an integrated driver that implements the
API that is used in the modules for command and control,
and for management and data packet traffic.
The Microchip TCP/IP software stack is available in the
free Microchip Application Libraries download
(including example applications and source code) from
the Microchip web site, http://www.microchip.com/
wireless.
The combination of the module and a PIC running the
TCP/IP stack results in support for IEEE Standard
802.11 and IP services. For example, this allows the
immediate implementation of a wireless web server
and e-mail clients.
The MRF24WG0MA/MB modules have received regu-
latory approvals for modular devices in the United
States (FCC), Canada (IC), and Europe (ETSI). The
modular approval removes the need for expensive RF
and antenna design, and allows the end user to place
the modules inside a finished product and not require
regulatory testing for an intentional radiator (RF trans-
mitter). See Section 3.0 “Regulatory Approval”, for
the specific requirements that should be adhered to by
the integrator.
MRF24WG0MA/MB
1.1 Interface Description
The block diagram in Figure 1-1 represents a
MRF24WG0MA/MB module. It interfaces to Microchip
PIC18, PIC24, dsPIC33, or PIC32 microcontrollers
through a four-wire serial slave SPI interface –
interrupt, hibernate, reset, power and ground signals.
The module runs on a single supply voltage of
nominally 3.3V. The serial trace port operates at 3.3V
and requires a level shifter for operation with RS-232
devices. This port provides a serial output of module
status messages and is helpful for debugging
purposes. Figure 1-2 shows a simplified example
connection between a Microchip PIC^® MCU and the
module. Table 1-1 lists the pin descriptions.
Data communications with the MRF24WG0MA/MB are
through the SPI interface that is detailed in Section 2.0
“Circuit Description”. The Microchip PIC microcon-
troller communicates with the module through a com-
mand API from within the Microchip TCP/IP stack. The
command API is detailed in the Microchip TCP/IP stack
online Help that is included in the free Microchip
Application Libraries download.
 2012 Microchip Technology Inc.
Preliminary Information
DS70686B-page 5