LR Series
Transmitter Module
Data Guide
! Warning: Some customers may want Linx radio frequency (“RF”)
products to control machinery or devices remotely, including machinery
or devices that can cause death, bodily injuries, and/or property
damage if improperly or inadvertently triggered, particularly in industrial
settings or other applications implicating life-safety concerns (“Life and
Property Safety Situations”).
Table of Contents
1^
1^
1^
NO OEM LINX REMOTE CONTROL OR FUNCTION MODULE
SHOULD EVER BE USED IN LIFE AND PROPERTY SAFETY
SITUATIONS. No OEM Linx Remote Control or Function Module
should be modified for Life and Property Safety Situations. Such
modification cannot provide sufficient safety and will void the product’s
regulatory certification and warranty.
2^
Customers may use our (non-Function) Modules, Antenna and
Connectors as part of other systems in Life Safety Situations, but
only with necessary and industry appropriate redundancies and
in compliance with applicable safety standards, including without
limitation, ANSI and NFPA standards. It is solely the responsibility
of any Linx customer who uses one or more of these products to
incorporate appropriate redundancies and safety standards for the Life
and Property Safety Situation application.
6^
Do not use this or any Linx product to trigger an action directly
from the data line or RSSI lines without a protocol or encoder/
decoder to validate the data. Without validation, any signal from
another unrelated transmitter in the environment received by the module
could inadvertently trigger the action.
All RF products are susceptible to RF interference that can prevent
communication. RF products without frequency agility or hopping
implemented are more subject to interference. This module does not
have a frequency hopping protocol built in.
Do not use any Linx product over the limits in this data guide.
Excessive voltage or extended operation at the maximum voltage could
cause product failure. Exceeding the reflow temperature profile could
cause product failure which is not immediately evident.
Do not make any physical or electrical modifications to any Linx
product. This will void the warranty and regulatory and UL certifications
and may cause product failure which is not immediately evident.
2^
3^
4^
6^
7^
8^
9^
9^
10^
10^
11^
12^
13^
14^
15^
15^
16^
17^
17^
19^
20^
20^
20^
22^
Description
Features
Applications
Ordering Information
Absolute Maximum Ratings
Electrical Specifications
Typical Performance Graphs
Pin Assignments
Pin Descriptions
Module Description
Theory of Operation
The Data Input
Using the PDN Line
Using the LADJ Line
Power Supply Requirements
Transferring Data
Typical Applications
ESD Concerns
Antenna Considerations
Helpful Application Notes from Linx
Protocol Guidelines
Interference Considerations
Pad Layout
Board Layout Guidelines
Microstrip Details
Production Guidelines
Hand Assembly
Automated Assembly
General Antenna Rules
24^
Common Antenna Styles
26^ Regulatory Considerations
LR Series Transmitter Module
Data Guide
Description
The LR Series transmitter is ideal for the cost-effective 0.360 in
TXM-315-LR
wireless transfer of serial data, control, or command (9.14 mm) LOT
RTxxxx
information in the favorable 260 to 470MHz band.
0.500 in
When paired with a compatible Linx receiver, a reliable
(12.7 mm)
0.130 in
wireless link is formed, capable of transferring serial
(3.3 mm)
data at rates of up to 10,000bps at distances of up
Typ.
to 3,000 feet (1,000m). Applications operating over
shorter distances or at lower data rates also benefit Figure 1: Package Dimensions
from increased link reliability and superior noise immunity. The transmitter’s
synthesized architecture delivers outstanding stability and frequency
accuracy and minimizes the affects of antenna pulling. Housed in a tiny
reflow-compatible SMD package, the transmitter requires no external RF
components except an antenna, which greatly simplifies integration and
lowers assembly costs.
Features
•
•
•
•
•
•
Long range
Low cost
PLL-synthesized architecture
Direct serial interface
Data rates up to 10,000bps
No external RF components
required
• Low power consumption
• Low supply voltage (2.1 to
3.6VDC)
• Compact surface-mount package
• Wide temperature range
• Power-down function
• No production tuning
Applications
•
•
•
•
•
•
Remote control
Keyless entry
Garage/gate openers
Lighting control
Medical monitoring/call systems
Remote industrial monitoring
•
•
•
•
•
•
– 1 –
Periodic data transfer
Home/industrial automation
Fire/security alarms
Remote status/position sensing
Long-range RFID
Wire elimination
Revised 3/18/2015
Ordering Information
Electrical Specifications
Ordering Information
LR Series Transmitter Specifications
Part Number
Description
Parameter
TXM-315-LR
315MHz Transmitter
Power Supply
TXM-418-LR
418MHz Transmitter
TXM-433-LR
433MHz Transmitter
RXM-315-LR
315MHz Receiver
RXM-418-LR
418MHz Receiver
Symbol
Min.
Typ.
Max.
Units
Operating Voltage
VCC
2.1
3.0
3.6
VDC
Supply Current
lCC
3.4
mA
1,2
5.1
mA
2
1.8
mA
5.0
nA
TXM-315-LR
315
MHz
TXM-418-LR
418
MHz
TXM-433-LR
433.92
MHz
Logic High
Logic Low
RXM-433-LR
433MHz Receiver
Power Down Current
EVAL-***-LR
LR Series Basic Evaluation Kit
Transmitter Section
lPDN
Transmit Frequency Range
*** = 315, 418 (Standard), 433MHz
Transmitters are supplied in tubes of 50 pcs.
Figure 2: Ordering Information
FC
Center Frequency Accuracy
Absolute Maximum Ratings
–50
Output Power
Absolute Maximum Ratings
PO
Output Power Control Range
Supply Voltage Vcc
−0.3
to
+3.6
VDC
Harmonic Emissions
Any Input or Output Pin
−0.3
to
VCC + 0.3
VDC
Data Rate
Operating Temperature
−40
to
+85
ºC
Data Input:
Storage Temperature
−40
to
+90
ºC
Soldering Temperature
+260ºC for 10 seconds
Exceeding any of the limits of this section may lead to permanent damage to the device.
Furthermore, extended operation at these maximum ratings may reduce the life of this
device.
Notes
–4
0.0
–80
PH
DC
Logic Low
VIL
Logic High
VIH
+50
kHz
+4
dBm
2
+10
dB
3
–36
dBc
10,000
bps
0.25
VDC
VCC–0.25
VDC
Power Down Input:
Logic Low
VIL
Logic High
VIH
0.25
VCC–0.25
VDC
VDC
Antenna Port
Figure 3: Absolute Maximum Ratings
RF Output Impedance
ROUT
50
Ω
4
1.0
ms
4
30.0
ns
4
+85
ºC
4
Timing
Transmitter Turn-On Time
Via VCC or PDN
Modulation Delay
Warning: This product incorporates numerous static-sensitive
components. Always wear an ESD wrist strap and observe proper ESD
handling procedures when working with this device. Failure to observe
this precaution may result in module damage or failure.
Environmental
Operating Temperature
1.
2.
3.
4.
–40
With a 50% duty cycle
With a 750Ω resistor on LADJ
See Figure 6 on page 4
Characterized, but not tested
Figure 4: Electrical Specifications
– 2 –
– 3 –
Typical Performance Graphs
2. 2.00V/div
4
1
Current Consumption (mA)
1. 500mV/div
4.5
3.5
3
2.5
2
2
6.00
3.00
0.00
-3.00
-6.00
Figure 7: Current Consumption vs. Output Power (50% of Duty Cycle)
100nS/div
Figure 5: Modulation Delay
12
LADJ Resistance (kΩ)
10
8
6
4
2
0
9.00
6.00
3.00
0.00
-3.00
-6.00
-9.00
Output Power (dBm)
-12.00
-15.00
-18.00
-21.00
Figure 6: Output Power vs. LADJ Resistor
– 4 –
-9.00
Output Power (dBm)
– 5 –
-12.00
-15.00
-18.00
-21.00
Pin Assignments
1
2
3
4
Module Description
GND
PDN
DATA
VCC
GND
GND
LADJ/VCC ANT
8
7
6
5
The module’s low power consumption makes it ideal for battery-powered
products. The transmitter is compatible with many other Linx receiver
products, including the LR, KH3, LT and OEM product families. For
applications where range is critical, the LR receiver is the best choice due
to its outstanding sensitivity.
Figure 8: LR Series Transmitter Pinout (Top View)
Pin Descriptions
Pin Descriptions
Pin Number
Name
I/O
Description
1
GND
—
Analog Ground
2
DATA
I
3
GND
—
4
The LR Series transmitter is a low-cost, high-performance synthesized
ASK / OOK transmitter, capable of sending serial data at up to 10,000bps.
Because the transmitter is completely self-contained, requiring an
antenna as the only additional RF component, application is extremely
straightforward and assembly and testing costs are reduced. The LR
is housed in a compact surface-mount package that integrates easily
into existing designs and is equally friendly to prototyping and volume
production. LR Series modules are capable of meeting the regulatory
requirements of domestic and international applications.
Digital Data Input
Analog Ground
Level Adjust. This line can be used to adjust
the output power level of the transmitter.
Connecting to VCC gives the highest output,
while placing a resistor to VCC lowers the
output level (see Figure 6 on page 4)
LADJ/VCC
I
5
ANT
—
50Ω RF Output
6
GND
—
Analog Ground
7
VCC
—
Supply Voltage
8
PDN
I
The transmitter is capable of outputting +10dBm into a 50-ohm load. When
combined with an LR Series receiver, a reliable serial link is formed capable
of transferring data over line-of-site distances of up to 1.5 miles (2,500m)
when used with good antennas. Legal regulations in the various countries
will require the transmitter output power to be reduced which will reduce
range. Following the legal output limit for transmitters in the United States,
systems based on the LR Series can achieve ranges of up to 3,000 feet
(1,000m).
Power Down. Pulling this line low places
the transmitter into a low-current state. The
module is not be able to transmit a signal in
this state.
Figure 9: Pin Descriptions
– 6 –
– 7 –
Theory of Operation
The Data Input
DATA
PDN
The CMOS-compatible data input on Pin 2 is normally supplied with a serial
bit stream from a microprocessor or encoder, but it can also be used with
standard UARTs.
PLL
VCO
PA
RF OUT
XTAL
Figure 10: LR Series Transmitter Block Diagram
The LR Series transmitter generates 1mW of output power into a 50-ohm
single-ended antenna while suppressing harmonics and spurious emissions
to within legal limits. The transmitter is comprised of a VCO locked by a
frequency synthesizer that is referenced to a high precision crystal. The
output of the VCO is amplified and buffered by an internal power amplifier.
The amplifier is switched by the incoming data to produce a modulated
carrier. The carrier is filtered to attenuate harmonics and then output on the
50Ω antenna port.
The synthesized topology makes the module highly immune to the
effects of antenna port loading and mismatch. This reduces or eliminates
frequency pulling, bit contraction, and other negative effects common to
low-cost transmitter architectures. It also allows for reliable performance
over a wide operating temperature range. Like its companion LR Series
receiver, the LR Series transmitter delivers a significantly higher level of
performance and reliability than the LC Series or other SAW-based devices,
yet remains very small and cost-effective.
– 8 –
When a logic ‘1’ is present on the DATA line and the PDN line is high, then
the Power Amplifier (PA) is activated and the carrier frequency is output on
the antenna port. When a logic ‘0’ is present on the DATA line or the PDN
line is low, the PA is deactivated and the carrier is fully suppressed.
The DATA line should always be driven with a voltage that is common
to the supply voltage present on Pin 7 (VCC). The DATA line should never
be allowed to exceed the supply voltage, as permanent damage to the
module could occur.
Using the PDN Line
The transmitter’s Power Down (PDN) line can be used to power down the
transmitter without the need for an external switch. It allows easy control of
the transmitter’s state from external components, such as a microcontroller.
By periodically activating the transmitter, sending data, then powering
down, the transmitter’s average current consumption can be greatly
reduced, saving power in battery operated applications.
The PDN line does not have an internal pull-up, so it needs to be pulled
high or tied directly to VCC to turn on the transmitter. The pull-up should be
a minimum of 30μA (10kΩ or less). When the PDN line is pulled to ground,
the transmitter enters a low-current (
