TXM-418-LC

TXM-FFF-LC LINX | Alldatasheet

Document overview

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• PDF pages: 17

Technical content

! Table of Contents

1 Description

1 Features

1 Applications

2 Ordering Information

2 Absolute Maximum Ratings

3 Electrical Specifications

4 Typical Performance Graphs

7 Pin Assignments

7 Pin Descriptions

8 Module Description

9 Theory of Operation

9 The Data Input

10 Adjusting the Output Power

11 Transferring Data

12 Power Supply Requirements

12 Typical Applications

13 ESD Concerns

14 Antenna Considerations

15 Helpful Application Notes from Linx

15 Protocol Guidelines

16 Interference Considerations

17 Pad Layout

17 Board Layout Guidelines

19 Microstrip Details

20 Production Guidelines

20 Hand Assembly

20 Automated Assembly

22 General Antenna Rules

24 Common Antenna Styles

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”). 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. 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. 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.

– –1 LC Series Transmitter Module Data Guide Revised 3/18/2015

Description

The LC Series is ideally suited for volume use in OEM applications such as remote control, security, identification and periodic data transfer. Housed in a compact surface-mount package, the LC Series transmitter utilizes a highly-optimized SAW architecture to achieve an unmatched blend of performance, size, efficiency and cost. When paired with a matching LR Series receiver, a highly reliable wireless link is formed, capable of transferring serial data at distances of up to 3,000 feet. No external RF components are required (except an antenna), making design and integration straightforward, even for engineers without previous RF experience.

Features

• Low cost
• No external RF components required
• Ultra-low power consumption
• Compact surface-mount package
• Stable SAW-based architecture
• Supports data ranges to 5,000bps
• Wide supply range (2.7 to 5.2VDC)
• Direct serial interface
• Low harmonics
• No production tuning

Applications

• Remote control
• Keyless entry
• Garage/gate openers
• Lighting control
• Medical monitoring/call systems
• Remote industrial monitoring
• Periodic data transfer
• Home/industrial automation
• Fire/security alarms
• Remote status/position sensing
• Long-range RFID
• Wire elimination TXM-315-LC LOT CTxxxx 0.360 in (9.14 mm) 0.500 in (12.7 mm) 0.150 in Max. (3.81 mm)

26 Regulatory Considerations

Figure 1: Package Dimensions

– – – –6 7 LADJ Resistor Value (Ω) 51 100 150 200 240 300 360 430 510 560 620 680 750 820 910 1.1K Output Power (dBm) Pin Assignments GND DATA GND GND ANTLADJ/GND GND VCC 4 5 Pin Descriptions Pin Number Name I/O Description

1 GND — Analog Ground

2 DATA I Digital Data Input

3 GND — Analog Ground

4 LADJ/GND I

Level Adjust. This line is used to adjust the output power level of the transmitter. Connecting to ground gives the highest output, while pacing a resistor to ground lowers the output level (see Figure 9 on page 6)

5 ANT — 50-ohm RF Output

6 GND — Analog Ground

7 VCC — Supply Voltage

8 GND — Analog Ground

Pin DescriptionsFigure 9: Output Power vs. LADJ Resistor Figure 10: LC Series Transmitter Pinout (Top View) Figure 11: Pin Descriptions

– – – –10 11 Adjusting the Output Power Depending on the type of antenna being used and the duty cycle of the data, the output power of the LC Series transmitter module may be higher than FCC regulations allow. The output power of the module is intentionally set high to compensate for losses resulting from inefficient antennas that may be used to realize cost or space savings. Since attenuation is often required, it is generally wise to provide for its implementation and allow the FCC test lab to easily attenuate the transmitter to the maximum legal limit for your product. Two methods of attenuation are available using the LC Series transmitter module. First, a resistor may be placed between Pin 4 (LADJ) and ground to achieve up to a 7dB reduction in output power. The resistor value is easily determined from Figure 9 on page 6. Do not exceed the resistance values shown as transmitter instability may result. This method can also be used to reduce the transmission range and power consumption. Another method commonly used to achieve attenuation, particularly at higher levels, is the use of a T-pad attenuator. A T-pad is a network of three resistors that allows for variable attenuation while maintaining the correct match to the antenna. It is usually prudent to allow space for the addition of a T-pad. An example of a T-pad attenuator layout is shown in Figure 14. For further details on T-pad attenuators, please refer to Application Note AN-00150. CIRCUIT TYPICAL LAYOUT WITH PROVISION FOR ATTENUATION GND ANT OUT PADS FOR SMD RESISTORS PADS FOR SMD RESISTORS ANT ANT GROUND PLANE ON LOWER LAYER GROUND PLANE ON LOWER LAYER GROUND GROUNDGROUND GROUND TXM-xxx-LC LOT CTxxxx Transferring Data Once a reliable 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. The LC Series is intended to be as transparent as possible and does not incorporate internal encoding or decoding, so a user has tremendous flexibility in how data is handled. If the product transfers simple control or status signals such as button presses or switch closures and it does not have a microprocessor on board (or it is desired to avoid protocol development), consider using a remote control encoder and decoder or a transcoder IC. These chips are available from a wide range of manufacturers including Linx. They take care of all encoding and decoding functions, and generally provide a number of data pins to which switches can be directly connected. In addition, address bits are usually provided for security and to allow the addressing of multiple units independently. These ICs are an excellent way to bring basic remote control / status products to market quickly and inexpensively. Additionally, it is a simple task to interface with inexpensive microprocessors, IR, remote control or modem ICs. It is always important to separate the types of transmissions that are technically possible from those that are legally allowable in the country of intended operation. Linx Application Notes AN-00125, AN-00128 and AN-00140 should be reviewed, along with Part 15, Section 231 of the Code of Federal Regulations for further details regarding acceptable transmission content in the US All of these documents can be downloaded from the Linx website at www.linxtechnologies.com. Another area of consideration is that the data structure can affect the output power level. The FCC allows output power in the 260 to 470MHz band to be averaged over a 100ms time frame. Because OOK modulation activates the carrier for a ‘1’ and deactivates the carrier for a ‘0’, a data stream that sends more ‘0’s has a lower average output power over 100ms. This allows the instantaneous output power to be increased, thus extending range. Figure 14: A T-Pad Attenuator Layout Example

– – – –16 17 Interference Considerations The RF spectrum is crowded and the potential for conflict with 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. 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. External interference can manifest itself in a variety of ways. Low-level interference produces noise and hashing on the output and reduces the link’s overall range. 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. Although technically 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 shorter useful distances for the link. Pad Layout The pad layout diagram in Figure 19 is designed to facilitate both hand and automated assembly. Board Layout Guidelines The module’s design makes integration straightforward; however, it is still critical to exercise care in PCB layout. Failure to observe good layout techniques can result in a significant degradation of the module’s performance. A primary layout goal is to maintain a characteristic 50-ohm impedance throughout the path from the antenna to the module. Grounding, filtering, decoupling, routing and PCB stack-up are also important considerations for any RF design. The following section provides some basic design guidelines. During prototyping, the module should be soldered to a properly laid-out circuit board. The use of prototyping or “perf” boards results in poor performance and is strongly discouraged. Likewise, the use of sockets can have a negative impact on the performance of the module and is discouraged. 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. When possible, separate RF and digital circuits into different PCB regions. Figure 19: Recommended PCB Layout 0.100" 0.070" 0.065" 0.340"

– – – –20 21 Production Guidelines The module is housed in a hybrid SMD package that supports hand and 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. Hand Assembly Pads located on the bottom of the module are the primary mounting surface (Figure 22). 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 prototyping and small volume 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 in Figure 23. Automated Assembly For high-volume assembly, the modules are generally auto-placed. The modules have been designed to maintain compatibility with reflow processing techniques; however, due to their hybrid nature, certain aspects of the assembly process are far more critical than for other component types. Following are brief discussions of the three primary areas where caution must be observed. CastellationsPCB Pads Soldering Iron Tip Solder Figure 22: Soldering Technique Warning: Pay attention to the absolute maximum solder times. Figure 23: Absolute Maximum Solder Times Absolute Maximum Solder Times Hand Solder Temperature: +427ºC for 10 seconds for lead-free alloys Reflow Oven: +255ºC max (see Figure 24) Reflow Temperature Profile The single most critical stage in the automated assembly process is the reflow stage. The reflow profile in Figure 24 should not be exceeded because excessive temperatures or transport times during reflow will irreparably damage the modules. Assembly personnel 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. 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 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. 125°C 185°C 217°C 255°C 235°C 60 12030 1501 80 2102 40 2703 00 3303 6009 0 100 150 200 250

300 Recommended RoHS Profile

Recommended Non-RoHS Profile 180°C Temperature (oC) Time (Seconds) Figure 24: Maximum Reflow Temperature Profile

– – – –26 27 Regulatory Considerations 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 a completed product. For information about regulatory approval, read AN-00142 on the Linx website or call Linx. Linx designs products with worldwide regulatory approval in mind. 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 United States 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 FCC’s website, 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. Final compliance testing is 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 the completed product has passed, an ID number is issued that is to be clearly placed on each product manufactured. Note: Linx RF modules are designed as component devices that require external components to function. The purchaser understands that additional 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. Questions regarding interpretations of the Part 2 and Part 15 rules or the 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 Equipment Authorization Division Customer Service Branch, MS 1300F2

7435 Oakland Mills Road

Columbia, MD, US 21046 Phone: + 1 301 725 585 | Fax: + 1 301 344 2050 Email: labinfo@fcc.gov ETSI Secretaria 650, Route des Lucioles

06921 Sophia-Antipolis Cedex

Phone: +33 (0)4 92 94 42 00 Fax: +33 (0)4 93 65 47 16 International approvals are slightly more complex, although Linx modules are designed to allow all international standards to be met. If the end product is to be exported to other countries, contact Linx to determine the specific suitability of the module to the application. 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.

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 Data 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 theories of recovery asserted by Customer, including, without limitation, breach of contract, breach of warranty, strict liability, or negligence. Customer assumes all liability (including, without limitation, liability for injury to person or property, economic loss, or business interruption) for all claims, including claims from third parties, arising from the use of the Products. The Customer will indemnify, defend, protect, and hold harmless Linx Technologies and its officers, employees, subsidiaries, affiliates, distributors, and representatives from and against all claims, damages, actions, suits, proceedings, demands, assessments, adjustments, costs, and expenses incurred by Linx Technologies as a result of or arising from any Products sold by Linx Technologies to Customer. Under no conditions will Linx Technologies be responsible for 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. ©2015 Linx Technologies. All rights reserved. The stylized Linx logo, Wireless Made Simple, WiSE, CipherLinx and the stylized CL logo are trademarks of Linx Technologies. Linx Technologies

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Merlin, OR, US 97532 Phone: +1 541 471 6256 Fax: +1 541 471 6251 www.linxtechnologies.com