TXM-900-HP3-PPS [ETC]
HP3 SERIES TRANSMITTER MODULE; HP3系列变送器模块型号: | TXM-900-HP3-PPS |
厂家: | ETC |
描述: | HP3 SERIES TRANSMITTER MODULE |
文件: | 总13页 (文件大小:399K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
HIGH-PERFORMANCE
RF MODULE
TXM-900-HP3-xxx
WIRELESS MADE SIMPLE ®
HP3 SERIES TRANSMITTER MODULE DATA GUIDE
DESCRIPTION
1.290"
The HP3 RF transmitter module is the third
HP SERIES RF TRANSMITTER
generation of the popular HP Series. Like its
predecessors, the HP3 is designed for the cost-
0.680"
TXM-900-HP3-SP*
LOT 10000
effective, high-performance wireless transfer of
Pin Spacing: 0.1"
analog or digital information in the popular 902-
0.178"
928MHz band. HP3 Series parts feature eight
parallel selectable channels, and some versions
also add direct serial selection of 100 channels.
SIP Style
1.260"
To ensure reliable performance, the transmitter
HP SERIES RF TRANSMITTER
TXM-900-HP3-SP*
0.628"
employs FM / FSK modulation and a micro-
LOT 10000
processor controlled synthesized architecture.
0.150"
Both SMD and pinned packages are available.
When paired with an HP3 receiver, a reliable
link is created for the transfer of analog and
SMD Style
Figure 1: Package Dimensions
digital information up to 1,000 feet. As with all Linx modules, the HP3 requires no
tuning or additional RF components (except an antenna), making integration
straightforward, even for engineers without prior RF experience.
FEATURES
APPLICATIONS INCLUDE
8 parallel, 100 serial (PS Versions) user-
selectable channels
FM / FSK modulation for outstanding
performance and noise immunity
Precision frequency synthesized
architecture
Transparent analog / digital interface
Wide-range analog capability including
audio (50Hz to 28kHz)
Wireless Networks / Data Transfer
Wireless Analog / Audio
Home / Industrial Automation
Remote Access / Control
Remote Monitoring / Telemetry
Long-Range RFID
MIDI Links
Voice / Music / Intercom Links
Wide temperature range
(-30°C to +85°C)
No external RF
ORDERING INFORMATION
PART #
DESCRIPTION
components required
Compatible with previous
HP Series modules
Power-down and CTS
functions
Wide supply range
(2.8 to 13.0VDC)
High data rate
TXM-900-HP3-PPO
HP3 Transmitter (SIP 8 CH only)
HP3 Transmitter (SIP 8p / 100s CH)
HP3 Transmitter (SMD 8 CH only)
HP3 Transmitter (SMD 8p / 100s CH)
HP3 Development Kit (SIP Pkg.)
HP3 Development Kit (SIP Pkg.)
HP3 Development Kit (SMD Pkg.)
HP3 Development Kit (SMD Pkg.)
TXM-900-HP3-PPS
TXM-900-HP3-SPO
TXM-900-HP3-SPS
MDEV-900-HP3-PPS-USB
MDEV-900-HP3-PPS-RS232
MDEV-900-HP3-SPS-USB
MDEV-900-HP3-SPS-RS232
(up to 56kbps)
Pinned and SMD packages
No production tuning
Transmitters are supplied in tubes of 15 pcs.
Revised 1/28/08
ELECTRICAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Parameter
Designation
Min.
Typical
Max.
Units
Notes
Supply Voltage VCC
-0.3
to
to
to
to
+18.0
VCC
+85
VDC
VDC
°C
POWER SUPPLY
Operating Voltage
Any Input or Output Pin
Operating Temperature
Storage Temperature
Soldering Temperature
-0.3
-30
-45
VCC
ICC
2.8
–
3.0
14.0
–
13.0
17.0
15.0
VDC
mA
µA
–
1
2
+85
°C
Supply Current
+260°C for 10 seconds
Power-Down Current
IPDN
–
TRANSMIT SECTION
*NOTE* 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.
Transmit Frequency Range
FC
902.62
–
927.62
MHz
3
Center Frequency Accuracy
Available Channels
Channel Spacing
–
–
-50
–
–
+50
100 (Ser.)
–
kHz
–
–
4
–
–
5
8 (Par.)
–
–
–
250
115
0
kHz
kHz
dBm
PERFORMANCE DATA
Occupied Bandwidth
Output Power
–
140
These performance parameters
are based on module operation at
25°C from a 5.0VDC supply unless
PO
-3
+3
GND
ANT
NC
NC
Spurious Emissions
Harmonic Emissions
–
–
–
-45
-60
–
dBm
dBm
6
6
PH
-47
GND
NC
otherwise
illustrates
necessary
noted.
the
for
Figure
connections
testing and
2
NC
CS0
NC
GND
NC
Data Rate
–
–
100
50
–
–
56,000
28,000
bps
Hz
7
7
PC
PC
PC
Analog / Audio Bandwidth
Data Input:
CS1 / SS CLOCK
CS2 / SS D
CTS
PDN
VCC
NC
NC
NC
NC
operation. It is recommended all
ground pins be connected to the
ground plane. The pins marked NC
have no electrical connection.
Logic Low
–
–
–
–
–
0.0
2.8
–
–
0.5
5.2
–
VDC
VDC
kΩ
kHz
kHz
–
–
–
8
8
5VDC
Logic High
–
Data Input Impedance
Frequency Deviation @ 3VDC
Frequency Deviation @ 5VDC
ANTENNA PORT
RF Output Impedance
200
70
115
MODE
DATA
NC
PC
60
90
110
140
GND
Figure 2: Test / Basic Application Circuit
ROUT
–
50
–
Ω
–
TIMING
TYPICAL PERFORMANCE GRAPHS
Transmitter Turn-On Time
Channel Change Time
ENVIRONMENTAL
–
–
–
–
7.0
1.0
10.0
1.5
mSec
mSec
–
–
V
/ PDN
V
CC
/ PDN
CC
Operating Temperature Range
–
-30
–
+85
°C
–
Table 1: HP3 Series Transmitter Specifications
1
1
Notes
RX DATA
2.5mS
1. Over the entire operating voltage range.
2. With the PDN pin low.
3. Serial Mode.
CTS
4. 100 serial channels on the PS versions only.
5. Does not change over the 3-13VDC supply.
6. Into 50 ohms.
7. The receiver will not reliably hold a DC level. See the HP3 Series Receiver Module Data Guide for the
minimum transition rate.
2
2
CH1 1.00V CH2 2.00V
Delta 7.200mS
CH1 1.00V CH2 2.00V
2.5mS
Delta 7.200mS
Figure 3: Power-Up to CTS
Figure 4: TX Powerup to Valid RX Data
8. The voltage specified is the modulation pin voltage.
IN
IN
*CAUTION*
OUT
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.
OUT
CH1 2.00V CH2 500mV
250μS
CH1 2.00V CH2 500mV
250μS
Figure 5: Sine Wave Modulation Linearity
Figure 6: Square Wave Modulation Linearity
Page 3
Page 2
PIN ASSIGNMENTS
PIN DESCRIPTIONS
Pin #
SMD Pinned
Pinned Transmitter
Surface-Mount Transmitter
Name
Equivalent Circuit
Description
1
2
3
4
5
6
7
8
9
GND
ANT
NC 24
NC 23
NC 22
NC 21
GND 20
NC 19
NC 18
NC 17
NC 16
NC 15
NC 14
GND 13
1, 3
13, 20
1
2
GND
ANT
Analog Ground
GND
NC
CS0
50Ω
RF
CS1 / SS CLOCK
CS2 / SS DATA
CTS
Out
2
50-ohm RF Output
Channel Select 0
PDN
10 VCC
11 MODE
12 DATA
25k
5
6
7
3
4
5
CS0
µ
CS0
CS1
CS2
Figure 7: HP3 Series Receiver Pinout
Channel Select 1 /
Serial Select Clock
CS1 /
SS CLOCK
25k
Pin #
Name
µ
Description
SMD SIP
Channel Select 2 /
Serial Select Data
CS2 /
SS DATA
25k
1
2
3
1
2
GND
ANT
GND
Analog Ground
50-ohm RF Output
µ
Analog Ground (SMD only)
No Electrical Connection. Soldered for physical support
only.
Clear-to-Send
Output
CTS
Out
4
5
NC
8
6
7
CTS
3
4
CS0
Channel Select 0
Channel Select 1 / Serial Select Clock. Channel Select 1
when in parallel channel selection mode, clock input for
serial channel selection mode.
Channel Select 2 / Serial Select Data. Channel Select 2
when in parallel channel selection mode, data input for
serial channel selection mode.
CS1 / SS
CLOCK
6
VCC
430k
Power Down
(Active Low)
9
PDN
CS2 / SS
DATA
PDN
7
8
9
5
6
7
Clear-To-Send. This line will go high when the transmitter
is ready to accept data.
CTS
VCC
10
11
8
Voltage Input 2.8-13V
Mode Select
Power Down. Pulling this line low will place the receiver
into a low-current state. The module will not be able to
receive a signal in this state.
PDN
VCC
25k
9
MODE
µ
MODE
10
11
8
9
Supply Voltage
160k
100k
510k
Mode Select. GND for parallel channel selection, VCC for
serial channel selection
MODE
12
10
DATA
NC
Digital / Analog Input
20pF
Digital / Analog Data Input. This line will output the
demodulated digital data.
12
10
DATA
GND
NC
4,
14-19,
21-24
SMD (Only)
No Electrical Connection
13, 20
Analog Ground (SMD only)
14-19,
21-24
Page 4
Figure 8: Pin Functions and Equivalent Circuits
No Electrical Connection. Soldered for physical support
only. (SMD only)
Page 5
THEORY OF OPERATION
POWER-UP SEQUENCE
The HP3 Series transmitter is a high-performance, multi-channel RF transmitter
capable of transmitting both analog (FM) and digital (FSK) information. FM / FSK
modulation offers significant advantages over AM or OOK modulation methods,
including increased noise immunity and the receiver’s ability to capture in the
presence of multiple signals. This is especially helpful in crowded bands, such
as the one in which the HP3 operates.
The HP3 transmitter is controlled by an
on-board microprocessor. When power is
applied, a start-up sequence is initiated.
At the end of the start-up sequence, the
transmitter is ready to transmit data.
POWER ON
Parallel Mode
Serial Mode
Determine Mode
Read Channel-
Selection Inputs
Program Freq. Synth
To Default CH. 50
The adjacent figure shows the start-up
sequence. It is executed when power is
applied to the VCC line or when the PDN
Crystal Oscillator
Begins to Operate
DATA
IN
Program Frequency
Synthesizer
28kHz Low Pass
line is taken high.
Ready for
Serial Data Input
Filter
Modulator
Crystal Oscillator
Begins to Operate
On power-up, the microprocessor reads
the external channel-selection lines and
sets the frequency synthesizer to the
appropriate channel. When the frequency
synthesizer has locked on to the proper
channel frequency, the circuit is ready to
accept data. This is acknowledged by the
CTS line transitioning high. The module
will then transmit data from the user’s
circuit.
MODE
CS0
CS1
μP
12MHz
Crystal
Program Frequency
Synthesizer
PLL
4MHz
Determine State of
CTS Output Line
Int. Osc.
Band Pass
Filter
CS2
Amplifier
Determine State of
CTS Output Line
Cycle Here Until
Channel
or Mode Change
RF OUT
VCO
Cycle Here Until More
Data Input, Mode Change,
or PLL Loses Lock
Figure 9: HP-3 Series Transmitter Block Diagram
A precision 12.00MHz Voltage Controlled Crystal Oscillator (VCXO) serves as
the frequency reference for the transmitter. Incoming data is filtered to limit the
bandwidth, and then used to directly modulate the reference. Direct reference
modulation inside the loop bandwidth provides fast start-up, while allowing a
wide modulation bandwidth and near DC modulation capability. This also
eliminates the need for code balancing.
Figure 10: Start-up Sequence
POWER SUPPLY
The HP3 incorporates a precision, low-dropout
regulator on-board, which allows operation over an
input voltage range of 2.8 to 13 volts DC. Despite this
regulator, it is still important to provide a supply that is
free of noise. Power supply noise can significantly
affect the transmitter modulation; therefore, providing
a clean power supply for the module should be a high
priority during design.
Vcc TO
MODULE
10Ω
The modulated 12.00MHz reference frequency is applied to the Phase-Locked
Loop (PLL). The PLL, combined with a 902 to 928MHz VCXO, forms a frequency
synthesizer that can be programmed to oscillate at the desired transmit
frequency. An on-board microcontroller manages the PLL programming and
greatly simplifies user interface. The microcontroller reads the channel selection
lines and programs the on-board synthesizer. This frees the designer from
complex programming requirements and allows for manual or software channel
selection. The microcontroller also monitors the status of the PLL and indicates
when the transmitter is ready to transmit data by pulling the CTS line high.
Vcc IN
+
10μF
Figure 11: Supply Filter
A 10Ω resistor in series with the supply followed by a
10µF tantalum capacitor from VCC to ground will help in cases where the quality
of supply power is poor. This filter should be placed close to the module’s supply
lines. These values may need to be adjusted depending on the noise present on
the supply line.
The PLL-locked carrier is amplified to increase the output power of the
transmitter and to isolate the VCO from the antenna. The output of the buffer
amplifier is connected to a filter network, which suppresses harmonic emissions.
Finally, the signal reaches the single-ended antenna port, which is matched to
50 ohms to support commonly available antennas, such as those from Linx.
USING THE PDN PIN
The Power Down (PDN) line can be used to power down the transmitter without
the need for an external switch. This line has an internal pull-up, so when it is
held high or simply left floating, the module will be active.
CTS OUTPUT
When the PDN line is pulled to ground, the transmitter will enter into a low-
current (<15µA) power-down mode. During this time, the transmitter is off and
cannot perform any function.
The Clear-To-Send (CTS) output goes high to indicate that the transmitter PLL
is locked and the module is ready to accept data. In a typical application, a
microcontroller will raise the PDN line high and begin to monitor the CTS line.
When the line goes high, the microcontroller will start sending data. It is not
necessary to use the CTS output, but if not used, the circuit should wait a
minimum of 10mS after raising the PDN line high before transmitting data. If data
is being sent redundantly, there is generally no need to monitor the CTS line or
to wait a fixed time, though the initial bits may not get through.
The PDN line allows easy control of the transmitter 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.
Page 6
Page 7
ADJUSTING THE OUTPUT POWER
TIMING CONSIDERATIONS
Depending on the type of antenna being used, the output power of the
transmitter may be higher than FCC regulations allow. It is intentionally set high
to compensate for losses resulting from inefficient antennas. Since attenuation is
often required, it is generally wise to provide for its implementation so that the
FCC test lab can easily attenuate the transmitter to the maximum legal limit.
Timing plays a key role in link reliability, especially when the modules are being
rapidly turned on and off or hopping channels. Unlike a wire, allowance must be
made for the programming and settling times of both the transmitter and
receiver, or portions of the signal will be lost. There are two major timing
considerations the engineer must consider when designing with the HP3 Series
transmitter. These are shown in the table below. The stated timing parameters
assume a stable supply of 2.8 volts or greater. They do not include the charging
times of external capacitance on the module’s supply lines, the overhead of
external software execution, or power supply rise times.
A T-pad is a network of three
resistors that allows for variable
attenuation while maintaining the
correct match to the antenna. An
example layout is shown in the
adjacent figure. For more details
on T-pad attenuators, please
see Application Note AN-00150.
ANTENNA
R1
R1
RF
MODULE
R2
Parameter
Description
Max.
10.0mS
1.5mS
GROUND PLANE
ON LOWER LAYER
T1
T2
Transmitter turn-on time
Channel change time (time to valid data)
GROUND
Figure 12: T-Pad Attenuator Example Layout
T1 is the maximum time required for the transmitter to power-up and lock on-
channel. This time is measured from the application of VCC to the CTS line
INPUTTING DIGITAL DATA
transitioning high.
T2 is the worst-case time needed for a powered-up module to switch between
channels after a valid channel selection. This time does not include external
overhead for loading a desired channel in Serial Channel Select Mode.
The DATA line may be directly connected to virtually any digital peripheral,
including microcontrollers, encoders, and UARTs. It has an impedance of 200kΩ
and can be used with any data that transitions from 0V to a 3 to 5V peak
amplitude within the specified data rate of the module. While it is possible to send
data at higher rates, the internal filter will cause severe roll off and attenuation.
Normally, the transmitter will be turned off after each transmission. This is
courteous use of the airwaves and reduces power consumption. The transmitter
may be shut down by switching its supply or the PDN line. When the transmitter
is again powered up, allowance must be made for the requirements above.
Many RF products require a fixed data rate or place tight constraints on the mark
/ space ratio of the data being sent. The HP3 transmitter architecture eliminates
such considerations and allows virtually any signal, including PWM, Manchester,
and NRZ data, to be sent at rates from 100bps to 56kbps.
In many cases, the transmitter will lock more quickly than the times indicated.
When turn-around time or power consumption are critical, the CTS line can be
monitored so data may be sent immediately upon transmitter readiness.
The HP3 does not encode or packetize the data in any manner. This
transparency gives the designer great freedom in software and protocol
development. A designer may also find creative ways to utilize the ability of the
transmitter to accept both digital and analog signals. For example, an application
might transmit voice, then send out a digital control command. Such mixed mode
systems can greatly enhance the function and versatility of many products.
TRANSMITTING DATA
Once an RF link has been established, the challenge becomes how to effectively
transfer data across it. While a properly designed RF link provides reliable data
transfer under most conditions, there are still distinct differences from a wired link
that must be addressed. Since the modules do not incorporate internal encoding
or decoding, the user has tremendous flexibility in how data is handled.
INPUTTING ANALOG SIGNALS
Analog signals from 50Hz to 28kHz may be connected directly to the
transmitter’s DATA line. The HP3 is a single supply device and, as such, is not
capable of operating in the negative voltage range. Analog sources should be
within 0 to 5VP-P and should, in most cases, be AC-coupled into the DATA line
It is important to separate the types of transmissions that are technically possible
from those that are legally allowed in the country of operation. Application Notes
AN-00126, AN-00140 and Part 15, Section 249 of the FCC rules should be
reviewed for details on acceptable transmission content in the U.S.
to achieve the best performance. The size of the coupling capacitor should be
large enough to ensure the passage of all desired frequencies and small enough
to allow the start-up time desired. Since the modulation voltage applied to the
DATA line determines the carrier deviation, distortion can occur if the DATA line
is over-driven. The actual level of the input waveform should be adjusted to
achieve optimum in-circuit results for your application.
If you want to transfer simple control or status signals (such as button presses)
and your product does not have a microprocessor or you wish to avoid protocol
development, consider using an encoder / decoder IC set. These chips are
available from several manufacturers, including Linx. They take care of all
encoding and decoding functions and provide a number of data lines to which
switches can be directly connected. Address bits are usually provided for
security and to allow the addressing of multiple receivers independently. These
ICs are an excellent way to bring basic remote control products to market quickly
and inexpensively. It is also a simple task to interface with inexpensive
microprocessors or one of many IR, remote control, DTMF, or modem ICs.
The HP3 is capable of providing audio quality comparable to a radio or intercom.
In applications where higher quality audio is required, a compandor may be
employed to increase dynamic range and reduce noise. If true high-fidelity audio
is required, the HP3 is probably not the best choice, as it is optimized for data.
Page 8
Page 9
CHANNEL SELECTION
Parallel Selection
SERIAL CHANNEL SELECTION TABLE
CHANNEL TX FREQUENCY
RX LO
867.92
868.17
868.42
868.67
868.92
869.17
869.42
869.67
869.92
870.17
870.42
870.67
870.92
871.17
871.42
871.67
871.92
872.17
872.42
872.67
872.92
873.17
873.42
873.67
873.92
874.17
874.42
874.67
874.92
875.17
875.42
875.67
875.92
876.17
876.42
876.67
876.92
877.17
877.42
877.67
877.92
878.17
878.42
878.67
878.92
879.17
879.42
879.67
879.92
880.17
880.42
CHANNEL
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
TX FREQUENCY
915.37
915.62
915.87
916.12
916.37
916.62
916.87
917.12
917.37
917.62
917.87
918.12
918.37
918.62
918.87
919.12
919.37
919.62
919.87
920.12
920.37
920.62
920.87
921.12
921.37
921.62
921.87
922.12
922.37
922.62
922.87
923.12
923.37
923.62
923.87
924.12
924.37
924.62
924.87
925.12
925.37
925.62
925.87
926.12
926.37
926.62
926.87
927.12
927.37
927.62
RX LO
880.67
880.92
881.17
881.42
881.67
881.92
882.17
882.42
882.67
882.92
883.17
883.42
883.67
883.92
884.17
884.42
884.67
884.92
885.17
885.42
885.67
885.92
886.17
886.42
886.67
886.92
887.17
887.42
887.67
887.92
888.17
888.42
888.67
888.92
889.17
889.42
889.67
889.92
890.17
890.42
890.67
890.92
891.17
891.42
891.67
891.92
892.17
892.42
892.67
892.92
CS2
0
0
0
0
1
1
1
1
CS1
0
0
1
1
0
0
1
1
CS0
0
1
0
1
0
1
0
1
Channel
Frequency
903.37
906.37
907.87
909.37
912.37
915.37
919.87
921.37
0
1
2
3
4
5
6
7
902.62
902.87
903.12
903.37
903.62
903.87
904.12
904.37
904.62
904.87
905.12
905.37
905.62
905.87
906.12
906.37
906.62
906.87
907.12
907.37
907.62
907.87
908.12
908.37
908.62
908.87
909.12
909.37
909.62
909.87
910.12
910.37
910.62
910.87
911.12
911.37
911.62
911.87
912.12
912.37
912.62
912.87
913.12
913.37
913.62
913.87
914.12
914.37
914.62
914.87
915.12
0
1
2
3
4
5
6
7
All HP3 transmitter models feature
eight parallel selectable channels.
Parallel Mode is selected by
grounding the MODE line. In this
mode, channel selection is deter-
mined by the logic states of pins CS0,
CS1, and CS2, as shown in the table.
A ‘0’ represents ground and a ‘1’ the supply. The on-board microprocessor
performs all PLL loading functions, eliminating external programming and
allowing channel selection via DIP switches or a product’s processor.
Table 2: Parallel Channel Selection Table
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50*
Serial Selection
In addition to the Parallel Mode, PS versions of the HP3 also feature 100 serially
selectable channels. The Serial Mode is entered when the MODE line is left open
or held high. In this condition, CS1 and CS2 become a synchronous serial port,
with CS1 serving as the clock line and CS2 as the data line. The module is easily
programmed by sending and latching the binary number (0 to 100) of the desired
channel (see the adjacent Serial Channel Selection Table). With no additional
effort, the module’s microprocessor handles the complex PLL loading functions.
The Serial Mode is
straightforward; however,
minimum timings and bit
order must be followed.
Loading is initiated by
taking the clock line high
and the data line low as
Variable Data
Note 2
Note 1
Data
1
2
3
4
5
6
7
8
Clock
T0
1ms
T3
Note 3
T4
5µs
8µs
T2
T1
25µs
5µs
shown.
The
eight-bit
1) Loading begins when clock line is high and data line is taken low
2) Ensure that edge is fully risen prior to high-clock transition
3) Both lines high triggers automatic latch
channel number is then
clocked-in one bit at a
time, with the LSB first.
(T0) Time between packets or prior to data startup ................................1mS min.
(T1) Data-LO / Clock-HI to Data-LO / Clock-LO.......................................25
(T2) Clock-LO to Clock-HI ...........................................................................5
(T3) Clock-HI to Clock-LO ...........................................................................8
(T4) Data-HI / Clock-HI .................................................................................5
Total Packet Time ......................................................................................157
µ
µ
µ
µ
µ
S min.
S min.
S min.
S min.
S min.
Figure 13: PLL Serial Data Timing
There is no maximum time for this process, only the minimum times that must be
observed. After the eighth bit, both the clock and data lines should be taken high
to trigger the automatic data latch. A typical software routine can complete the
loading sequence in under 200μS. Sample code is available on the Linx website.
NOTE: When the module is powered up in the Serial Mode, it will default to channel 50 until changed
by user software. This allows testing apart from external programming and prevents out-of-band
operation. When programmed properly, the dwell time on this default channel can be less than 200μS.
Channel 50 is not counted as a usable channel since data errors may occur as transmitters also default
to channel 50 on startup. If a loading error occurs, such as a channel number >100 or a timing problem,
the receiver will default to serial channel 0. This is useful for debugging as it verifies serial port activity.
= Also available in Parallel Mode
*See NOTE on previous page.
Page 10
Page 11
PROTOCOL GUIDELINES
TYPICAL APPLICATIONS
While many RF solutions impose data formatting and balancing requirements,
Linx RF modules do not encode or packetize the signal content in any manner.
The received signal will be affected by such factors as noise, edge jitter, and
interference, but it is not purposefully manipulated or altered by the modules.
This gives the designer tremendous flexibility for protocol design and interface.
The figure below shows a typical RS-232 circuit using the HP3 Series transmitter
and a Maxim MAX232. The MAX232 converts RS-232 compliant signals to a
serial data stream, which the transmitter then sends. The MODE line is
grounded, so the channels are selected by the DIP switches.
VCC
VCC
Despite this transparency and ease of use, it must be recognized that there are
distinct differences between a wired and a wireless environment. Issues such as
interference and contention must be understood and allowed for in the design
process. To learn more about protocol considerations, we suggest you read Linx
Application Note AN-00160.
C1
4.7uF
+
C2
4.7uF
DB-9
1
6
2
7
3
8
4
9
5
1
2
24
23
22
21
20
19
18
17
16
GND
ANT
NC
NC
+
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
GND
C3
4.7uF
C1+
V+
C1-
C2+
C2-
V-
VCC
GND
T1OUT
R1IN
R1OUT
T1IN
T2IN
3
GND
NC
4
5
6
NC
NC
Errors from interference or changing signal conditions can cause corruption of
the data packet, so it is generally wise to structure the data being sent into small
packets. This allows errors to be managed without affecting large amounts of
data. A simple checksum or CRC could be used for basic error detection. Once
an error is detected, the protocol designer may wish to simply discard the corrupt
data or implement a more sophisticated scheme to correct it.
CS0
GND
NC
+
C4
4.7uF
CS1 / SS CLOCK
CS2 / SS DATA
CTS
PDN
VCC
GND
VCC
T2OUT
R2IN
7
NC
NC
NC
NC
R2OUT
8
9
10
11
12
MAX232
GND
C5
4.7uF
14
13
GND
MODE
NC
DATA
GND
TXM-900-HP3
GND
GND
INTERFERENCE CONSIDERATIONS
Figure 14: HP3 Transmitter and MAX232 IC
The RF spectrum is crowded and the potential for conflict with other unwanted
sources of RF is very real. While all RF products are at risk from interference, its
effects can be minimized by better understanding its characteristics.
The figure below shows a circuit using the QS Series USB module. The QS
converts USB compliant signals from a PC to serial data to be sent to the
transmitter. The MODE line is high, so the module is in Serial Channel Select
Mode. The RTS and DTR lines are used to load the channels. Application Note
AN-00155 shows sample source code that can be adapted to use on a PC. The
QS Series Data Guide and Application Note AN-00200 discuss the hardware
and software set-up required for QS Series modules.
Interference may come from internal or external sources. The first step is to
eliminate interference from noise sources on the board. This means paying
careful attention to layout, grounding, filtering, and bypassing in order to
eliminate all radiated and conducted interference paths. For many products, this
is straightforward; however, products containing components such as switching
power supplies, motors, crystals, and other potential sources of noise must be
approached with care. Comparing your own design with a Linx evaluation board
can help to determine if and at what level design-specific interference is present.
USB-B CONNECTOR
4
GND
GND
GND
DAT+
DAT -
5V
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
24
23
22
21
20
19
18
3
USBDP
USBDM
GND
RI
DCD
GND
ANT
NC
NC
1
DSR
GND
NC
External interference can manifest itself in a variety of ways. Low-level
interference will produce noise and hashing on the output and reduce the link’s
overall range.
VCC
DATA_IN
NC
CS0
NC
GND
NC
GND
SUSP_IND DATA_OUT
GND GND
RX_IND
TX_IND
485_TX
RTS
CTS
DTR
CS1 / SS CLOCK
CS2 / SS DATA
CTS
NC
High-level interference is caused by nearby products sharing the same
frequency or from near-band high-power devices. It can even come from your
own products if more than one transmitter is active in the same area. It is
important to remember that only one transmitter at a time can occupy a
frequency, regardless of the coding of the transmitted signal. This type of
interference is less common than those mentioned previously, but in severe
cases it can prevent all useful function of the affected device.
9
VCC
PDN
VCC
SDM-USB-QS
NC
NC
11
12
14
13
MODE
DATA
GND
TXM-900-HP3
GND
Figure 15: HP3 Transmitter and Linx QS Series USB Module
The transmitter can also be connected to a microcontroller, which will generate
the data based on specific actions. A UART may be employed or an I / O line
may be “bit banged” to send the data to the transmitter. The transmitter may be
connected directly to the microcontroller without the need for buffering or
amplification.
Although technically it is not interference, multipath is also a factor to be
understood. Multipath is a term used to refer to the signal cancellation effects
that occur when RF waves arrive at the receiver in different phase relationships.
This effect is a particularly significant factor in interior environments where
objects provide many different signal reflection paths. Multipath cancellation
results in lowered signal levels at the receiver and, thus, shorter useful distances
for the link.
Page 12
Page 13
BOARD LAYOUT GUIDELINES
MICROSTRIP DETAILS
If you are at all familiar with RF devices, you may be concerned about
specialized board layout requirements. Fortunately, because of the care taken by
Linx in designing the modules, integrating them is very straightforward. Despite
this ease of application, it is still necessary to maintain respect for the RF stage
and exercise appropriate care in layout and application in order to maximize
performance and ensure reliable operation. The antenna can also be influenced
by layout choices. Please review this data guide in its entirety prior to beginning
your design. By adhering to good layout principles and observing some basic
design rules, you will be on the path to RF success.
A transmission line is a medium whereby RF energy is transferred from one
place to another with minimal loss. This is a critical factor, especially in high-
frequency products like Linx RF modules, because the trace leading to the
module’s antenna can effectively contribute to the length of the antenna,
changing its resonant bandwidth. In order to minimize loss and detuning, some
form of transmission line between the antenna and the module should be used,
unless the antenna can be placed very close (<1/8in.) to the module. One
common form of transmission line is a coax cable, another is the microstrip. This
term refers to a PCB trace running over a ground plane that is designed to serve
as a transmission line between the module and the antenna. The width is based
on the desired characteristic impedance of the line, the thickness of the PCB,
and the dielectric constant of the board material. For standard 0.062in thick FR-
4 board material, the trace width would be 111 mils. The correct trace width can
be calculated for other widths and materials using the information below. Handy
software for calculating microstrip lines is also available on the Linx website,
www.linxtechnologies.com.
The adjacent figure shows the suggested
PCB footprint for the module. The actual pad
GRROUND PLANE
ONN LLOOWER LAYER
dimensions are shown in the Pad Layout
section of this manual. A ground plane (as
large as possible) should be placed on a
lower layer of your PC board opposite the
module. This ground plane can also be critical
to the performance of your antenna, which will
be discussed later. There should not be any
Trace
ground or traces under the module on the
same layer as the module, just bare PCB.
Figure 16: Suggested PCB Layout
Board
During prototyping, the module should be soldered to a properly laid-out circuit
board. The use of prototyping or “perf” boards will result in horrible performance
and is strongly discouraged.
Ground plane
No conductive items should be placed within 0.15in of the module’s top or sides.
Do not route PCB traces directly under the module. The underside of the module
has numerous signal-bearing traces and vias that could short or couple to traces
on the product’s circuit board.
The module’s ground lines should each have their own via to the ground plane
and be as short as possible.
AM / OOK receivers are particularly subject to noise. The module should, as
much as reasonably possible, be isolated from other components on your PCB,
especially high-frequency circuitry such as crystal oscillators, switching power
supplies, and high-speed bus lines. Make sure internal wiring is routed away
from the module and antenna, and is secured to prevent displacement.
The power supply filter should be placed close to the module’s VCC line.
In some instances, a designer may wish to encapsulate or “pot” the product.
Many Linx customers have done this successfully; however, there are a wide
variety of potting compounds with varying dielectric properties. Since such
compounds can considerably impact RF performance, it is the responsibility of
the designer to carefully evaluate and qualify the impact and suitability of such
materials.
Figure 17: Microstrip Formulas
Effective Dielectric
Constant
Characteristic
Impedance
Dielectric Constant Width/Height (W/d)
The trace from the module to the antenna should be kept as short as possible.
A simple trace is suitable for runs up to 1/8-inch for antennas with wide
bandwidth characteristics. For longer runs or to avoid detuning narrow bandwidth
antennas, such as a helical, use a 50-ohm coax or 50-ohm microstrip
transmission line as described in the following section.
4.80
4.00
2.55
1.8
2.0
3.0
3.59
3.07
2.12
50.0
51.0
48.0
Page 14
Page 15
PAD LAYOUT
AUTOMATED ASSEMBLY
The following pad layout diagram is designed to facilitate both hand and
automated assembly.
For high-volume assembly, most users will want to auto-place the modules. The
modules have been designed to maintain compatibility with reflow processing
techniques; however, due to the their hybrid nature, certain aspects of the
assembly process are far more critical than for other component types.
Pinned Transmitter
Surface-Mount Transmitter
0.065
Following are brief discussions of the three primary areas where caution must be
observed.
0.070
0.060
0.100
Reflow Temperature Profile
0.060
0.3"
0.628
The single most critical stage in the automated assembly process is the reflow
stage. The reflow profile below should not be exceeded, since excessive
temperatures or transport times during reflow will irreparably damage the
modules. Assembly personnel will need to pay careful attention to the oven’s
profile to ensure that it meets the requirements necessary to successfully reflow
all components while still remaining within the limits mandated by the modules.
The figure below shows the recommended reflow oven profile for the modules.
0.030 Dia. Finished
0.100
Figure 18: Recommended PCB Layout
PRODUCTION GUIDELINES
300
Recommended RoHS Profile
Max RoHS Profile
Recommended Non-RoHS Profile
The modules are housed in a hybrid SMD package that supports hand or
automated assembly techniques. Since the modules contain discrete
components internally, the assembly procedures are critical to ensuring the
reliable function of the modules. The following procedures should be reviewed
with and practiced by all assembly personnel.
255°C
250
200
150
100
50
235°C
217°C
185°C
180°C
HAND ASSEMBLY
Pads located on the bottom of the
module are the primary mounting
surface. Since these pads are
inaccessible during mounting,
castellations that run up the side of
the module have been provided to
facilitate solder wicking to the
module’s underside. This allows for
very quick hand soldering for
Soldering Iron
125°C
Tip
Solder
PCB Pads
0
30
60
90
120
150
Time (Seconds)
180
210
240
270
300
330
360
Castellations
prototyping and small volume
Figure 20: Maximum Reflow Profile
Figure 19: Soldering Technique
production.
If the recommended pad guidelines have been followed, the pads will protrude
slightly past the edge of the module. Use a fine soldering tip to heat the board
pad and the castellation, then introduce solder to the pad at the module’s edge.
The solder will wick underneath the module, providing reliable attachment. Tack
one module corner first and then work around the device, taking care not to
exceed the times listed below.
Shock During Reflow Transport
Since some internal module components may reflow along with the components
placed on the board being assembled, it is imperative that the modules not be
subjected to shock or vibration during the time solder is liquid. Should a shock
be applied, some internal components could be lifted from their pads, causing
the module to not function properly.
Washability
Absolute Maximum Solder Times
The modules are wash resistant, but are not hermetically sealed. Linx
recommends wash-free manufacturing; however, the modules can be subjected
to a wash cycle provided that a drying time is allowed prior to applying electrical
power to the modules. The drying time should be sufficient to allow any moisture
that may have migrated into the module to evaporate, thus eliminating the
potential for shorting damage during power-up or testing. If the wash contains
contaminants, the performance may be adversely affected, even after drying.
Hand-Solder Temp. TX +225°C for 10 Seconds
Hand-Solder Temp. RX +225°C for 10 Seconds
Recommended Solder Melting Point +180°C
Reflow Oven: +220°C Max. (See adjoining diagram)
Page 16
Page 17
ANTENNA CONSIDERATIONS
GENERAL ANTENNA RULES
The choice of antennas is a critical
The following general rules should help in maximizing antenna performance.
and
consideration.
often
overlooked
The
design
range,
1. Proximity to objects such as a user’s hand, body, or metal objects will cause an
antenna to detune. For this reason, the antenna shaft and tip should be
positioned as far away from such objects as possible.
performance, and legality of an RF link
are critically dependent upon the
antenna. While adequate antenna
performance can often be obtained by
trial and error methods, antenna
design and matching is a complex
2. Optimum performance will be obtained
from a 1/4- or 1/2-wave straight whip
mounted at a right angle to the ground
plane. In many cases, this isn’t desirable
OPTIMUM
for practical or ergonomic reasons, thus,
NOT RECOMMENDED
task.
A
professionally designed
Figure 21: Linx Antennas
USEABLE
an alternative antenna style such as a
helical, loop, or patch may be utilized
antenna, such as those from Linx, will
help ensure maximum performance and FCC compliance.
Figure 23: Ground Plane Orientation
and the corresponding sacrifice in performance accepted.
Linx transmitter modules typically have an output power that is slightly higher
than the legal limits. This allows the designer to use an inefficient antenna, such
as a loop trace or helical, to meet size, cost, or cosmetic requirements and still
achieve full legal output power for maximum range. If an efficient antenna is
used, then some attenuation of the output power will likely be needed. This can
easily be accomplished by using the LADJ line or a T-pad attenuator. For more
details on T-pad attenuator design, please see Application Note AN-00150.
3. If an internal antenna is to be used, keep it away from other metal components,
particularly large items like transformers, batteries, PCB tracks, and ground
planes. In many cases, the space around the antenna is as important as the
antenna itself. Objects in close proximity to the antenna can cause direct
detuning, while those farther away will alter the antenna’s symmetry.
4. In many antenna designs, particularly 1/4-wave
VERTICAL λ/4 GROUNDED
ANTENNA (MARCONI)
whips, the ground plane acts as a counterpoise,
forming, in essence, a 1/2-wave dipole. For this
reason, adequate ground plane area is essential.
A receiver antenna should be optimized for the frequency or band in which the
receiver operates and to minimize the reception of off-frequency signals. The
efficiency of the receiver’s antenna is critical to maximizing range performance.
Unlike the transmitter antenna, where legal operation may mandate attenuation
or a reduction in antenna efficiency, the receiver’s antenna should be optimized
as much as is practical.
E
DIPOLE
ELEMENT
λ/4
The ground plane can be a metal case or ground-fill
I
areas on a circuit board. Ideally, it should have a
surface area > the overall length of the 1/4-wave
radiating element. This is often not practical due to
size and configuration constraints. In these
instances, a designer must make the best use of the
area available to create as much ground plane as
GROUND
PLANE
VIRTUAL λ/4
DIPOLE
λ/4
It is usually best to utilize a basic quarter-wave whip until your prototype product
is operating satisfactorily. Other antennas can then be evaluated based on the
cost, size, and cosmetic requirements of the product. You may wish to review
Application Note AN-00500 “Antennas: Design, Application, Performance”
Figure 24: Dipole Antenna
possible in proximity to the base of the antenna. In cases where the antenna is
remotely located or the antenna is not in close proximity to a circuit board,
ground plane, or grounded metal case, a metal plate may be used to maximize
the antenna’s performance.
ANTENNA SHARING
In cases where a transmitter and receiver
module are combined to form a transceiver,
0.1μF
it is often advantageous to share a single
Module
V
DD
Transmitter
0.1μF
Antenna
5. Remove the antenna as far as possible from potential interference sources. Any
frequency of sufficient amplitude to enter the receiver’s front end will reduce
system range and can even prevent reception entirely. Switching power
supplies, oscillators, or even relays can also be significant sources of potential
interference. The single best weapon against such problems is attention to
placement and layout. Filter the module’s power supply with a high-frequency
bypass capacitor. Place adequate ground plane under potential sources of noise
to shunt noise to ground and prevent it from coupling to the RF stage. Shield
noisy board areas whenever practical.
antenna. To accomplish this, an antenna
switch must be used to provide isolation
between the modules so that the full
0.1μF
GND
0.1μF
GND
Receiver
Module
transmitter output power is not put on the
0.1μF
sensitive front end of the receiver. There
Select
are a wide variety of antenna switches that
are cost-effective and easy to use. Among
Figure 22: Typical Antenna Switch
the most popular are switches from Macom and NEC. Look for an antenna
switch that has high isolation and low loss at the desired frequency of operation.
Generally, the Tx or Rx status of a switch will be controlled by a product’s
microprocessor, but the user may also make the selection manually. In some
cases, where the characteristics of the Tx and Rx antennas need to be different
or antenna switch losses are unacceptable, it may be more appropriate to utilize
two discrete antennas.
6. In some applications, it is advantageous to
place the module and antenna away from the
CASE
main equipment. This can avoid interference
problems and allows the antenna to be
oriented for optimum performance. Always use
GROUND PLANE
NUT
(MAY BE NEEDED)
50Ω coax, like RG-174, for the remote feed.
Figure 25: Remote Ground Plane
Page 19
Page 18
COMMON ANTENNA STYLES
ONLINE RESOURCES
There are literally hundreds of antenna styles and variations that can be
employed with Linx RF modules. Following is a brief discussion of the styles
most commonly utilized. Additional antenna information can be found in Linx
Application Notes AN-00100, AN-00140, and AN-00500. Linx antennas and
connectors offer outstanding performance at a low price.
®
www.linxtechnologies.com
• Latest News
A whip-style antenna provides outstanding overall performance
Whip Style
and stability. A low-cost whip is can be easily fabricated from a
wire or rod, but most designers opt for the consistent
performance and cosmetic appeal of a professionally-made
model. To meet this need, Linx offers a wide variety of straight
and reduced-height whip-style antennas in permanent and
connectorized mounting styles.
• Data Guides
• Application Notes
• Knowledgebase
• Software Updates
The wavelength of the operational frequency determines an
antenna’s overall length. Since a full wavelength is often quite
If you have questions regarding any Linx product and have Internet access,
make www.linxtechnologies.com your first stop. Our website is organized in an
intuitive format to immediately give you the answers you need. Day or night, the
Linx website gives you instant access to the latest information regarding the
products and services of Linx. It’s all here: manual and software updates,
application notes, a comprehensive knowledgebase, FCC information, and much
more. Be sure to visit often!
long, a partial 1/2- or 1/4-wave antenna is normally employed.
Its size and natural radiation resistance make it well matched to
Linx modules. The proper length for a straight 1/4-wave can be
easily determined using the adjacent formula. It is also possible
to reduce the overall height of the antenna by using a helical
winding. This reduces the antenna’s bandwidth, but is a great
way to minimize the antenna’s physical size for compact
applications. This also means that the physical appearance is
not always an indicator of the antenna’s frequency.
234
L =
F
MHz
Where:
L
= length in feet of
quarter-wave length
F = operating frequency
in megahertz
Specialty Styles
Linx offers a wide variety of specialized antenna styles.
Many of these styles utilize helical elements to reduce the
overall antenna size while maintaining reasonable
performance. A helical antenna’s bandwidth is often quite
narrow and the antenna can detune in proximity to other
objects, so care must be exercised in layout and placement.
www.antennafactor.com
The Antenna Factor division of Linx offers
a diverse array of antenna styles, many of
which are optimized for use with our RF
modules. From innovative embeddable
antennas to low-cost whips, domes to
Yagis, and even GPS, Antenna Factor
likely has an antenna for you, or can
design one to meet your requirements.
A loop- or trace-style antenna is normally printed directly on a
product’s PCB. This makes it the most cost-effective of antenna
styles. The element can be made self-resonant or externally
resonated with discrete components, but its actual layout is
usually product specific. Despite the cost advantages, loop-style
antennas are generally inefficient and useful only for short-range
applications. They are also very sensitive to changes in layout and
PCB dielectric, which can cause consistency issues during
production. In addition, printed styles are difficult to engineer,
requiring the use of expensive equipment, including a network
analyzer. An improperly designed loop will have a high SWR at the
desired frequency, which can cause instability in the RF stage.
Loop Style
www.connectorcity.com
Through its Connector City division, Linx offers a wide
selection of high-quality RF connectors, including FCC-
compliant types such as RP-SMAs that are an ideal
match for our modules and antennas. Connector City
focuses on high-volume OEM requirements, which
allows standard and custom RF connectors to be offered
at a remarkably low cost.
Linx offers low-cost planar and chip antennas that mount directly
to a product’s PCB. These tiny antennas do not require testing and
provide excellent performance in light of their small size. They
offer a preferable alternative to the often-problematic “printed”
antenna.
Page 20
Page 21
LEGAL CONSIDERATIONS
ACHIEVING A SUCCESSFUL RF IMPLEMENTATION
Adding an RF stage brings an exciting new
DECIDE TO UTILIZE RF
NOTE: Linx RF modules are designed as component devices that require
external components to function. The modules are intended to allow for full Part
15 compliance; however, they are not approved by the FCC or any other agency
worldwide. The purchaser understands that approvals may be required prior to
the sale or operation of the device, and agrees to utilize the component in keeping
with all laws governing its use in the country of operation.
dimension to any product. It also means that
additional effort and commitment will be needed to
bring the product successfully to market. By utilizing
premade RF modules, such as the LR Series, the
design and approval process is greatly simplified. It
is still important, however, to have an objective view
of the steps necessary to ensure a successful RF
integration. Since the capabilities of each customer
vary widely, it is difficult to recommend one
particular design path, but most projects follow steps
similar to those shown at the right.
RESEARCH RF OPTIONS
ORDER EVALUATION KIT(S)
TEST MODULE(S) WITH
BASIC HOOKUP
CHOOSE LINX MODULE
When working with RF, a clear distinction must be made between what is technically
possible and what is legally acceptable in the country where operation is intended. Many
manufacturers have avoided incorporating RF into their products as a result of
uncertainty and even fear of the approval and certification process. Here at Linx, our
desire is not only to expedite the design process, but also to assist you in achieving a
clear idea of what is involved in obtaining the necessary approvals to legally market your
completed product.
INTERFACE TO CHOSEN
CIRCUIT AND DEBUG
CONSULT LINX REGARDING
ANTENNA OPTIONS AND DESIGN
LAY OUT BOARD
In reviewing this sample design path, you may
notice that Linx offers a variety of services (such as
antenna design and FCC prequalification) that are
unusual for a high-volume component manufacturer.
These services, along with an exceptional level of
technical support, are offered because we recognize
that RF is a complex science requiring the highest
caliber of products and support. “Wireless Made
Simple” is more than just a motto, it’s our
commitment. By choosing Linx as your RF partner
and taking advantage of the resources we offer, you
SEND PRODUCTION-READY
PROTOTYPE TO LINX
FOR EMC PRESCREENING
OPTIMIZE USING RF SUMMARY
GENERATED BY LINX
In the United States, the approval process is actually quite straightforward. The
regulations governing RF devices and the enforcement of them are the responsibility of
the Federal Communications Commission (FCC). The regulations are contained in Title
47 of the Code of Federal Regulations (CFR). Title 47 is made up of numerous volumes;
however, all regulations applicable to this module are contained in Volume 0-19. It is
strongly recommended that a copy be obtained from the Government Printing Office in
Washington or from your local government bookstore. Excerpts of applicable sections are
included with Linx evaluation kits or may be obtained from the Linx Technologies website,
www.linxtechnologies.com. In brief, these rules require that any device that intentionally
radiates RF energy be approved, that is, tested for compliance and issued a unique
identification number. This is a relatively painless process. Linx offers full FCC pre-
screening, and final compliance testing is then performed by one of the many
independent testing laboratories across the country. Many labs can also provide other
certifications that the product may require at the same time, such as UL, Class A / B, etc.
Once your completed product has passed, you will be issued an ID number that is to be
clearly placed on each product manufactured.
SEND TO PART 15
TEST FACILITY
RECEIVE FCC ID #
COMMENCE SELLING PRODUCT
Typical Steps For
Implementing RF
will not only survive implementing RF, you may even find the process enjoyable.
HELPFUL APPLICATION NOTES FROM LINX
It is not the intention of this manual to address in depth many of the issues that
should be considered to ensure that the modules function correctly and deliver
the maximum possible performance. As you proceed with your design, you may
wish to obtain one or more of the following application notes, which address in
depth key areas of RF design and application of Linx products. These
applications notes are available online at www.linxtechnologies.com or by
contacting the Linx literature department.
Questions regarding interpretations of the Part 2 and Part 15 rules or measurement
procedures used to test intentional radiators, such as Linx RF modules, for compliance
with the technical standards of Part 15, should be addressed to:
Federal Communications Commission
Office of Engineering and Technology Laboratory Division
7435 Oakland Mills Road
NOTE
AN-00100
APPLICATION NOTE TITLE
RF 101: Information for the RF Challenged
Columbia, MD 21046-1609
Phone: (301) 362-3000 Fax: (301) 362-3290 E-Mail: labinfo@fcc.gov
International approvals are slightly more complex, although Linx modules are designed
to allow all international standards to be met. If you are considering the export of your
product abroad, you should contact Linx Technologies to determine the specific suitability
of the module to your application.
AN-00126
AN-00130
AN-00140
AN-00155
AN-00160
AN-00500
Considerations For Operation Within The 902-928MHz Band
Modulation Techniques For Low-Cost RF Data Links
The FCC Road: Part 15 From Concept To Approval
Serial Loading Techniques for the HP Series 3
All Linx modules are designed with the approval process in mind and thus much of the
frustration that is typically experienced with a discrete design is eliminated. Approval is
still dependent on many factors, such as the choice of antennas, correct use of the
frequency selected, and physical packaging. While some extra cost and design effort are
required to address these issues, the additional usefulness and profitability added to a
product by RF makes the effort more than worthwhile.
Considerations For Sending Data Over a Wireless Link
Antennas: Design, Application, Performance
Page 22
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WIRELESS MADE SIMPLE ®
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FAX: (541) 471-6251
www.linxtechnologies.com
Disclaimer
Linx Technologies is continually striving to improve the quality and function of its products. For this reason,
we reserve the right to make changes to our products without notice. The information contained in this
Overview Guide is believed to be accurate as of the time of publication. Specifications are based on
representative lot samples. Values may vary from lot-to-lot and are not guaranteed. "Typical" parameters can
and do vary over lots and application. Linx Technologies makes no guarantee, warranty, or representation
regarding the suitability of any product for use in any specific application. It is the customer's responsibility
to verify the suitability of the part for the intended application. NO LINX PRODUCT IS INTENDED FOR USE
IN ANY APPLICATION WHERE THE SAFETY OF LIFE OR PROPERTY IS AT RISK.
Linx Technologies DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. IN NO EVENT SHALL LINX TECHNOLOGIES BE LIABLE FOR ANY OF
CUSTOMER'S INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY FROM ANY DEFECTIVE
OR NON-CONFORMING PRODUCTS OR FOR ANY OTHER BREACH OF CONTRACT BY LINX
TECHNOLOGIES. The limitations on Linx Technologies' liability are applicable to any and all claims or
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losses arising from the use or failure of the device in any application, other than the repair, replacement, or
refund limited to the original product purchase price. Devices described in this publication may contain
proprietary, patented, or copyrighted techniques, components, or materials. Under no circumstances shall
any user be conveyed any license or right to the use or ownership of such items.
© 2008 by Linx Technologies, Inc. The stylized Linx logo,
Linx, “Wireless Made Simple”, CipherLinx, and the stylized
CL logo are the trademarks of Linx Technologies, Inc.
Printed in U.S.A.
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