RADIO MODULE
MXR-505
UHF FM TRANSCEIVER MODULE
Y
R
A
IN
IM
L
E
R
P
DATA SHEET
Radios, Inc.
May 30, 2007 Preliminary Data Sheet
MXR-505
UHF FM TRANSCEIVER MODULE
The MXR-505 is a frequency shift keyed (FSK) high performance,
ultra compact, long range transceiver operating at the 902-928
MHz and 868.25 MHz bands. This integrated modularized trans-
ceiver is designed for use in half-duplex, bidirectional RF links.
The multi-channeled MXR-505 is intended for use in UHF radio
equipment in compliance with both the North American Federal
Communications Commission (FCC) part 15.247 and 15.249 sys-
tems and the European Telecommunications Standard Institute
(ETS) specification EN300 200.
The transmitter is composed of both a PLL frequency synthesizer and a power amplifier. The synthesizer
uses a voltage-controlled crystal oscillator, a dual-modulus prescaler, programmable frequency dividers,
and a phase-detector. The power amplifier’s output power can be programmed to seven different levels.
The MXR-505 has zero IF architecture which enables channel filtering with low-power, integrated low-
pass filters. Each channel includes a pre-amplifier and a third order Sallen-Key RC low-pass filter that
protects the switched-capacitor filter from strong adjacent channel signals. The main channel filter is a
switched-capacitor implementation of a six-pole elliptic low pass filter. The cutoff frequency of the
Sallen-Key RC filter can be programmed to four different frequencies: 100kHz, 150 kHz, 230 kHz, and
340 kHz. A receive signal strength indicator circuit indicates the received signal level. The MXR-505 is
a well-designed transceiver suitable for a variety of RF applications, particularly voice applications and
high volume OEM applications.
Key Features
Y
R
A
IN
IM
L
E
R
P
Typical Applications
Low cost
Wide supply voltage range
Wide operating temperature range
Easily integrated
Low power consumption
Compact surface-mount packages/Small Size
2.5V operation
Simple serial programming interface
Baud rate from 1200 to 200,000 bps
Spread spectrum
External reset pin
Exceptional sensitivity: -111dBm
Receive signal stength (RSSI) pin
No production tuning
Remote controls
Garage openers / Gate controls
Keyless entry
Lighting control
Home / Industrial automation
Continuous / Periodic data transfer
Wireless networking
Remote access
Remote monitoring / Telemetry
Medical monitoring / Call systems
Guard patrol / Lone worker protection
Domestic / Commercial security
Fire / Security alarms
Long-range RFID
Automated meter reading
Contact Information
Radios, Inc.
1408 Center Avenue
Oostburg, WI 53070
Phone: 920-564-6622
Fax: 920-564-6630
Email: sales@radiosinc.com
-Page 2-
MXR-505
UHF FM TRANSCEIVER MODULE
Mechanical and Pin Diagram
* Note: Pinouts of surface mount and through-hole packages are mirrored
DIP Package
Pin Description
Pin Num Pin Name
Pin 1
Pin 2
Pin 3
Pin 4
Pin 5
Pin 6
Pin 7
Pin 8
Pin 9
Pin 10
Pin 11
Pin 12
RST/NMI
TEST
TDO
TDI
TMS
TCK
Gnd
Gnd
Gnd
Gnd
Gnd
Ant
Description
No Connect
No Connect
No Connect
No Connect
No Connect
No Connect
Ground
Ground
Ground
Ground
Ground
RF Input/Output (50 Ohms)
Pin Num Pin Name
Pin 13
Pin 14
Pin 15
Pin 16
Pin 17
Pin 18
Pin 19
Pin 20
Pin 21
Pin 22
Pin 23
Pin 24
+VIN
+2.5V
REG-EN
N/C
N/C
N/C
N/C
DATACLK
DATAIXO
RSSI
UTXD
URXD
Description
Positive Supply Pin (2.6-16V)
Regulated Output (2.5V)
Regulator Enable (2-VCC)
No Connect
No Connect
No Connect
No Connect
Data Clock Output (0-2.5V)
Data Input/Output (0-2.5V)
Receive Signal Strength Indicator (0-2.5V)
Transmit Data Out—UART mode (0-2.5V)
Receive Data Out—UART mode (0-2.5V)
PRELIMINARY
-Page 3-
MXR-505
UHF FM TRANSCEIVER MODULE
Mechanical and Pin Diagram
* Note: Pinouts of surface mount and through-hole packages are mirrored
Surface Mount Package
Pin Description
Pin Num Pin Name
Pin 1
Pin 2
Pin 3
Pin 4
Pin 5
Pin 6
Pin 7
Pin 8
Pin 9
Pin 10
Pin 11
Pin 12
Ant
Gnd
Gnd
Gnd
Gnd
Gnd
TCK
TMS
TDI
TDO
TEST
RST/NMI
Description
RF Input/Output (50 Ohms)
Ground
Ground
Ground
Ground
Ground
No Connect
No Connect
No Connect
No Connect
No Connect
No Connect
Pin Num Pin Name
Pin 13
Pin 14
Pin 15
Pin 16
Pin 17
Pin 18
Pin 19
Pin 20
Pin 21
Pin 22
Pin 23
Pin 24
URXD
UTXD
RSSI
DATAIXO
DATACLK
N/C
N/C
N/C
N/C
REG-EN
+2.5V
+VIN
Description
Receive Data Out—UART mode (0-2.5V)
Transmit Data Out—UART mode (0-2.5V)
Receive Signal Strength Indicator (0-2.5V)
Data Input/Output (0-2.5V)
Data Clock Output (0-2.5V)
No Connect
No Connect
No Connect
No Connect
Regulator Enable (2-VCC)
Regulated Output (2.5V)
Positive Supply Pin (2.6-16V)
PRELIMINARY
-Page 4-
MXR-505
UHF FM TRANSCEIVER MODULE
MXR-505 Communication
Communication with the MXR-505 is accomplished through a universal asynchronous receive/
transmit (UART) peripheral interface. The UART uses 8-bit, non-parity, LSB, 1200bps baud
format. The maximum number of data bytes that can be transmitted or received in one packet is 50.
The user will transmit data through the UART on the MXR-505 via pin 24, URXD. The MXR-505
will packetize and wirelessly transmit the data. Once the data is received on the other side, the
MXR-505 will demodulate the data and send the received data out to the user via pin 23, UTXD.
The data being sent through the UART should follow a specific protocol.
The communication protocol is outlined below:
Byte #1
Number of Bytes
– The number of bytes is one byte containing the total number of
data bytes. This byte should not be included in the number of bytes. Therefore, the
number of bytes should be one less than the total number of bytes being sent or
received. The maximum number of data bytes that can be transmitted or received is
50; therefore, the number of bytes should not exceed 50.
Bytes #2-51 Data Bytes
– The data bytes are the actual data byte values being transmitted or
received by the MXR-505. The MXR-505 can send or receive a maximum of 50
data bytes per packet. The first two bytes are used as preamble bytes by Radios,
Inc. to differentiate the detection of data from noise. They can be set to any value,
but to work with the HHDS-ML they must be set to 0xFF and 0x00, respectively.
When the first byte is received through the UART on the MXR-505, the user will have one second
to send the remaining data bytes to the MXR-505. If the MXR-505 does not receive all of the data
bytes within that second, the data the MXR-505 did receive will be dumped. For example, if the
user sends a 10 for the number of bytes and then only sends five more bytes within one second, the
MXR-505 assumes this is corrupted data and does not transmit the packet. The five bytes the
MXR-505 did receive will be discarded and the MXR-505 will wait for a new packet of data to be
received.
Y
R
A
IN
IM
L
E
R
P
Electrical Limits
Parameters
Min
2.6
-0.5
0
Sym
VCC
Typ
Max
16
2.7
70
Unit Notes
V
V
°C
°C
V
kV
°C/W
V
°C
V
EN
V
EN
TA
Absolute Maximum Ratings
Supply Voltage
Voltage on any Pins
Storage Temperature Range
Lead Temperature
Enable Input Voltage
ESD Rating
Operating Ratings
Package Thermal Resistance
Enable Input Voltage
Ambient operating temperature
260
0
16
0
0
VCC
70
-Page 5-