433-RM

TXM-418 LINX | Alldatasheet

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D E S C R I P T I O N : The LINX TXM-XXX-RM Series is an advanced ultra - compact SAW-based transmitter module.When paired with a Linx Technologies RM Series receive r, the units create a highly reliable link c a p a ble of tra n s fe r ri n g analogue or high-speed digital data at distances in excess of 500 ft.L i ke all Linx modules, the RM S e ries needs no production tuning or adjustment and requires no ex t e rnal RF components (ex c e p t an antenna).O b s e rving simple design ru l e s, the module is easily integrated even by engineers l a cking previous RF ex p e ri e n c e. R MSERIES T R A N S M I T T E RMODULE DATA G U I D E HI G HPE R F O R M A N C E R FM O D U L E T X M - 4 1 8 / 4 3 3 - R M n Remote Control / Access Control n Remote Monitoring / Te l e m e t ry n Medical Alert n Remote Industrial Process Monitori n g n Pe riodic Data Tra n s fe r n Lighting Control n G a rage/Gate Openers n S e c u rity / Fire Alarm s n Wire Elimination A P P L I C ATIONS INCLUDE: n Compact SIP-style mounting n No production tuning or setup n Direct analog or digital input n Precision SAW- s t a b i l i zed FM/FSK modulation n S u p p o rts high data rates (up to 10 Kbps) n Wide supply range (5.9-9 vDC) n L ow power consumption (6mA Ty p i c a l ) n Wide operating temperature ra n g e F E ATURE HIGHLIGHTS: PA RT # DESCRIPTION M D E V- 4 1 8 - R ME valuation Kit 418 MHz T X M - 4 1 8 - R M - * *Transmitter 418 MHz R X M - 4 1 8 - R M - * *R e c e i ver 418 MHz M D E V- 4 3 3 - R ME valuation Kit 433 MHz T X M - 4 3 3 - R M - * *Transmitter 433 MHz R X M - 4 3 3 - R M - * *R e c e i ver 433 MHz ** Insert TB for Tube Pa ck a g i n g O R D E R I N GI N F O R M AT I O N R evised 2/8/00 P hysical Outline

The RM Series is a SAW- ( S u r face Acoustic Wave) based transmitter designed to be utilized in combination with a matching RM Series receive r. By adding a simple antenna, the pair can tra n s fer serial data at distances well in ex c e s s of 500 fe e t .The range of the RF link is widely va ri a ble and depends upon m a ny factors including the type of antenna employed and the opera t i n g e nv i r o n m e n t .The 500 ft. quoted range is a conserva t i ve operating distance over open ground using 1/4-whip antennae at both ends of the link at 5 fe e t a b ove the gr o u n d .Use of a less efficient antenna or adverse env i r o n m e n t a l factors such as interfe r e n c e, obstacles, or multipath can substantially reduce the link’s reliable wo rking ra n g e.S l owing the data rate or utilizing a directional antenna (especially on the receiver) can provide increased perfo rmance bu t m ay not comply with licensing requirements. It is recommended that yo u r individual application be rev i ewed with Linx prior to entering production or seeking approva l s. fi g u re 1: LINX-TX bl o ck diagra m THE SAW BASED DESIGN ADV A N TA G E The SAW (Surface Acoustic Wave) device provides a highly accura t e frequency source with excellent immunity to frequency shift due to age or t e m p e ra t u r e. By using a SAW to insure accurate frequency control on the t ransmitter module the receive r ’s pass opening can be quite narrow, resulting in outstanding sensitivity and greater immunity to interfe ring signals. In order to frequency modulate this carrier the SAW is ex t e rnally pulled to obtain the n e c e s s a ry dev i a t i o n . By employing a SAW on both the RM transmitter and receiver the units prov i d e an excellent perfo rmance ri valing far more complex and costly systems.T h e S AW de v i c e, in combination with advanced design and manu fa c t u ri n g t e c h n i q u e s, has made it possible to dramatically reduce the size and cost of an RF link while enhancing its perfo rm a n c e. The end user benefits from i m p r oved product range and reliability and the OEM manu facturer from lowe r cost and simpler manu fa c t u ring procedures.

fi g u re 2:M e chanical dimensions PIN DESCRIPTION Pin 1 G N D Connect to common gr o u n d - p l a n e. Pin 2 RF OUT For connection to ex t e rnal antenna. Output impedance is 50Ω . Pin 3 V c c Po s i t i ve supply pin, supply voltages from +5.9 to +9 volts may be u s e d . Pin 4 GND Connect to common g r o u n d - p l a n e. Pin 5 DATA IN Analog or digital input. Should be dri ven by the same supply voltage as the module. Usually interfaced with a CMOS logic l evel dev i c e. Should never exceed V c c . PHYSICAL P A C K A G I N G The transmitter is packaged as a hy b rid SIP module with five pins spaced 0.1 i n .on center.The SIP package allows easy accommodation of both hori zo n t a l and ve rtical mounting requirements into a highly compact pack a g e. Its leaded design allows for easy prototyping and simple integration into through-hole and surface-mount designs. If the module will be bent and laid flush on the circuit board, a pad of silicon or other adhesive should be used to hold it in p l a c e. W H AT EXTERNAL COMPONENTS ARE REQUIRED ? The RM Series transmitter requires only a supply vo l t a g e, an ex t e rnal antenna and analog or digital input. Production adjustment or tuning is not required.

PERFORMANCE DATA – RM SERIES TRANSMITTER Pe r formance Data Pa r a m e t e rs : Ambient tempera t u r e : 2 0 ° C Supply vo l t a g e : +8 vo l t s, unless noted otherwise Test circuit: configured as shown in figure 3 fi g u re 3: LINX RM Series test circ u i t Pa r a m e t e r M i n . Ty p i c a lM a x M e a s u r eN o t e s O p e rating supply range (Vcc) 5 . 9 6 . 0 9 . 0 Vo l t s – Supply current Vcc = 6.0V 3 . 0 6 . 0 1 0 . 0 m A – Vcc = 9.0V 5 . 0 1 0 . 0 1 7 . 0 m A – Field strength of fundamental Vcc = 6.0V - 4 - 1 + 4 d B m 1 Transmit frequency RM Modules are ava i l a ble in 418 & 433.92 MHz Initial frequency accura c y - 8 0 – + 8 0 K H z – O ve rall frequency accura c y - 9 5 – 9 5 K H z 2 S p u rious ra d i a t i o n C a p a ble of meeting FCC Pa rt 15 FM deviation (+/-) 1 5 2 5 4 0 K H z 3 Modulation Bandwidth (-3dB) analog D C – 1 0 K H z 3 Digital data ra t e 1 0 0 – 1 0 , 0 0 0B P S 4 Data input vo l t a g e 0vDC to V c c M a x .data ra t e < = 5 K b p s N o t e s : 1 Into 50Ω load. 2 Supply 5.9 to 9 volt, temp -10˚ to +55˚ C. 3 2 KHz square wave, 0 to V c c . 4 High or low pulse. Absolute Maximum Ratings: Supply voltage V c c pin 3 -0.7 to +12 vo l t s Modulation input pin 5 -0.7 to +12 v o l t s O p e rating tempera t u r e -10°C to +55°C S t o rage tempera t u r e -40°C to +100°C * N OTE* Exceeding any of the limits of this section may lead to permanent damage to the d ev i c e.F u rt h e r m o r e, extended operation at these maximum ratings may reduce the life of this dev i c e.

fi g u re 4: Typical perfo rmance curve s POWER SUPPLY REQUIREMENTS The transmitter module requires a clean, well-regulated vo l t a g e. While it is p r e fe ra ble to power the unit from a battery, the unit can also be powered from a power supply as long as noise and ‘ h a s h ’is less than 20mV. A 10µF capacitor to ground on pin 5 (Vcc) and a 10Ω series resistor will help in cases where the quality of supply power is poor. The module is not reverse polarity protected.R everse supply voltages will cause permanent damage.E x t e rnal polarity protection is recommended. Fi g u re 5:S u ggested supply fi l t e r

BOARD LAYOUT CONSIDERA T I O N S If you are at all familiar with RF devices you may be concerned about s p e c i a l i zed layout requirements. Fo rt u n a t e l y, because of the care taken in design, integrating an RM transmitter into your design is ve ry stra i g h t fo r wa r d . By adhering carefully to a few basic design and layout ru l e s, you can enjoy a t r o u ble-free path to RF success. Figure 6 shows the suggested PCB fo o t p rint for the RM tra n s m i t t e r. 1 )A ground-plane (as large as p o s s i ble) should be placed directly under the RM tr a n s m i t t e r. T h i s ground-plane can also be critical to the perfo rmance of your antenna. 2) The RM transmitter should, as mu c h as reasonably possibl e, be isolated from all other components on your PCB. S p e c i f i c a l l y, high-frequency circuitry such as crystal oscillators should be kept as far away as possible from the tra n s m i t t e r. 3) The module may be mounted ve rtically or bent hori zontal to the product’s P C B. If the transmitter is to be mounted parallel to the board, it should be bent over so that the side without components is closest to the PC board and the component side is facing away from the PC board. 4 )No conductive items should be placed within .25 in. of the module’s component side to prevent detuning. 5 )The trace from the transmitter to the antenna should be kept as short as p o s s i bl e. A simple trace is suitable for runs up to 1/4 inch for antennas with wide bandwidth chara c t e ri s t i c s. For longer runs or to avoid detuning a high- Q narrow bandwidth antenna such as a helical, use a 50-ohm coax or 50- ohm microstrip transmission line as shown in figure 7. Depending on the type antenna being used, the output power of the RM module may be significantly higher than F C Cregulations allow. The output power of the module is intentionally set high since many designers pair the module with an inefficient antenna in order to realize cost or space sa v i n g s. S i n c e a t t e nuation is commonly required a designer may want to place locating pads in-line with the antenna t race as show n .In the event that a T-pad is required the antenna trace can be cut and the pads populated. For further details on T-pads please refer to Linx application note #00150. fi g u re 6: Recommended PCB fo o t p ri n t fi g u re 7:M i c ro s t rip transmission line

This is an example of a basic remote control design utilizing a Holtek encoder/decoder IC. When a key is pressed at the tra n s m i t t e r, a corresponding pin at the receiver goes high. This basic circuit can be easily modified to suit a broad range of applications, and clearly demonstrates the ease of using and i n t e r facing the Linx modules. fi g u re 8: Basic wireless encoder circ u i t BASIC REMOTE CONTROL EXAMPLE M O D U L ATION REQUIREMENTS The RM transmitter has a DC to 10 KHz modulation bandwidth and will accept direct analog (AFSK) or digital data. A modulation lowpass filter (10 KHz @ -6 dB, 1st order) is used intern a l l y. Digital data is normally input to pin 5 in a serial stream at CMOS logic leve l s such as those from a microprocessor or encoder IC. The maximum data ra t e is 10Kbps. The pin should always be dri ven with a voltage common to the supply voltage present at pin 3 (Vcc). Under no condition should the vo l t a g e at the data pin be allowed to exceed the supply voltage (Vcc). D ATA CODING Once a reliable RF link has been established, the challenge becomes how to most effe c t i vely tra n s fer data across it. Since the transmit and receive modules have no internal digital coding/decoding, a user has tremendous f l exibility to send many types of analog and digital data. It is important to understand, howeve r, that some intelligent transmission structure must be u s e d .This is true for seve ral reasons. The first and most significant is that there must be some way to distinguish an intended transmission from i n t e r ferers and ambient noise. In addition, it is generally not possible to hold DC levels across an RF link, therefo r e, transitions must take place at m i n i mum interva l s. It is, of course, a simple task to also accomplish application-specific data encoding and tra n s fer using a microprocessor.I n ex p e n s i ve micros such as the Microchip PIC series make an excellent choice for this task. If you do not have a microprocessor on-board your product and you want to send control signals such as a key press, switch closing, or low - rate data, consider using an encoder and decoder IC chipset. These chips take care of all encoding, error checking, and decoding functions and are ava i l a ble from L i n x .An example of such an application is shown below.

ANTENNA CONSIDERA T I O N S The range of the RF link is widely va ri a ble and depends upon the type of antenna employe d and the operating env i r o n m e n t .Proper design and matching of an antenna is a complex task requiring sophisticated test equipment and a strong back ground in principles of RF p r o p a g a t i o n .While adequate antenna perfo rmance can often be obtained by trial and error m e t h o d s, you may also want to consider utilizing a premade antenna from Linx. Our low - c o s t antenna line is designed to ensure maximum perfo rmance and Pa rt 15 compliance. It is usually best to utilize a basic quart e r - wave whip for your initial concept eva l u a t i o n .T h i s can easily be made from a piece of wire as shown on the next page. Once the prototype product is operating satisfa c t o ri l y, a production antenna should be selected to meet the cost, s i ze and cosmetic requirements of the product. It is important to recognize that the antenna p l ays a significant role in determining the perfo rmance and legality of your end product.I n order to gain a better understanding of the considerations invo l ved in the design and selection of antennas, please rev i ew Linx applications note #00500 “ A n t e n n a s :D e s i g n , Application, Pe r fo rm a n c e ” . The fo l l owing notes should help in ach i eving optimum antenna perfo r m a n c e : 1 . P r oximity to objects such as a user’s hand or body, or metal objects will cause an antenna to detune. For this reason the antenna shaft and tip should be positioned as fa r away from such objects as possibl e. 2 . O p t i mum perfo rmance will be obtained from a 1/4- or 1/2-wave straight whip mounted at a right angle to the gr o u n d - p l a n e. In many cases this isn’t desira ble fo r p ractical or ergonomic reasons;t h u s, an altern a t i ve antenna style such as a helical, l o o p, patch, or base-loaded whip may be utilize d . 3 . It is always a good practice to include a T- a t t e nuation pad as described under "Board Layout Considera t i o n s " .This allows your product's output power to be adjusted for certification purposes without change or compromise to the antenna. 4 . If an internal antenna is to be used, keep it away from other metal components, p a rt i c u l a rly large items like tra n s fo rm e r s, batteri e s, and PCB tra cks and gr o u n d - p l a n e s. In many cases, the space around the antenna is as important as the antenna itself. 5 . In many antenna designs, part i c u l a rly 1/4-wave whips, the ground-plane acts as a c o u n t e rp o i s e, fo rming, in essence, a 1/2-wave dipole. For this reason adequate gr o u n d - plane area is essential. As a general rule the ground-plane to be used as counterp o i s e should have a surface area ≥ the ove rall length of the 1/4-wave radiating element. 6 . R e m ove the antenna as far as possible from potential internal interference sources. Switching power supplies, oscillators, even relays can also be significant sources of potential interfe r e n c e. The single best weapon against such problems is attention to placement and layo u t .Filter the module’s power supply with a high-frequency by p a s s c a p a c i t o r. Place adequate ground-plane under all potential sources of noise.S h i e l d noisy board areas whenever pra c t i c a l . 7 . In some applications it is advantageous to place the transmitter and its antenna away from the main equipment. This avoids interference problems and allows the antenna to be oriented for optimum RF perfo rm a n c e.A l ways use 50Ω coax such as RG-174 for the remote fe e d . PA R A M E T E R L O O P H E L I C A L W H I P Ultimate perfo r m a n c e l l l l l l Ease of design setup l l l l l l S i ze l l l l l l I m munity to proximity effe c t s l l l l l l l = FAIR l l= G O O D l l l= E X C E L L E N T Antenna Selection Chart

A whip-style monopole antenna provides outstanding ove ra l l p e r fo rmance and stability. A low-cost whip can be easily fa b ri c a t e d from wire or rod, but most product designers opt for the improve d p e r fo rmance and cosmetic appeal of a professionally made model. To meet this need, Linx offers a wide va riety of straight and redu ced-he ight whip-style antennas in permanent and c o n n e c t o ri zed mounting styles. The wavelength of the operational frequency determines an antenna's ove rall length. Since a full wavelength is often quite long, a partial 1/4-wave antenna is normally employe d .Its size and n a t u ral radiation resistance make it well matched to Linx modules. The proper length for a 1/4-wave antenna can be easily fo u n d using the fo rmula below. It is also possible to reduce the ove ra l l height of the antenna by using a helical winding. This decreases the antenna's bandwidth but is an excellent way to minimize the antenna's physical size for compact applications. Page 9 Helical Style Whip Style Loop Style 1/4 wave wire lengths fo r R M f r e q u e n c i e s : 418MHz = 6.7" 433MHz = 6.5" COMMON ANTENNA STYLES There are literally hundreds of antennas styles that can be successfully employed with the RM Seri e s. Fo l l owing is a brief discussion of the three styles most commonly utilize d in compact RF designs. Additional antenna info rmation can be found in Linx application notes #00500, #00100, #00126 and #00140. A helical antenna is precisely fo rmed from wire or rod. A helical antenna is a good choice for low-cost products requiring ave ra g e range perfo rmance and internal concealment. A helical can detune badly in proximity to other objects and its bandwidth is quite narrow so care must be exercised in layout and placement. A loop- or trace-style antenna is normally printed directly on a product's PCB. This makes it the most cost-effe c t i ve of antenna s t y l e s. There are a va riety of shapes and layout styles which can be u t i l i ze d .The element can be made self-resonant or ex t e rn a l l y resonated with discrete components. Despite its cost adva n t a g e s, PCB antenna styles are generally inefficient and useful only for short - range applications. Loop-style antennas are also ve ry sensitive to changes in layout or substrate dielectric which can introduce consistency issues into the production process. In addition, pri n t e d styles initially are difficult to engineer, requiring the use of ex p e n s i ve equipment including a netwo rk analyze r. An improperly designed loop will have a high SWR at the desired frequency which can introduce substantial instability in the RF stages. Linx offers a low-cost planar antenna called the “ S P L AT C H ”which is an excellent altern a t i ve to the sometimes problematic PCB tra c e s t y l e. This tiny antenna mounts directly to a product's PCB and requires no testing or tuning. Its design is stable even in compact applications and it provides excellent perfo rmance in light of its compact size. W h e r e : L=length in feet of quart e r - wave length F = o p e rating frequency in megahert z

L E G A LC O N S I D E R AT I O N S When w o rking with RF, a clear distinction must be made between what is technically possible and what is legally acceptable in the country where opera t i o n is intended.M a ny man u facturers have avoided incorp o rating RF into their products as a result of uncertainty and even fear of the approval and cert i f i c a t i o n p r o c e s s. Here at Linx our desire is not only to expedite the design process, bu t also to assist you in achieving a clear idea of what is invo l ved in obtaining the a p p r ovals necessary to legally market your completed product. In the United States the approval process is actually quite stra i g h t fo r wa r d .T h e regulations gove rning RF devices and the enforcement of them are the responsibility of the Fe d e ral Communications Commission. The regulations are contained in the Code of Fe d e ral Regulations (CFR), Title 47. Title 47 is made up of numerous vo l u m e s ;h owev e r, all regulations applicable to this module are contained in volume 0-19. It is strongly recommended that a copy be obtained from the Gove rnment Printing Office in Washington, or from your local gove rn m e n t book store. E x c e rpts of applicable sections are included with Linx evaluation kits or may be obtained from the Linx Technologies web site ( w w w. l i n x t e c h n o l o g i e s. c o m ) .In bri e f, these rules require that any device which intentionally radiates RF energy be approved, that is, tested, for compliance and issued a unique identification nu m b e r. This is a relatively painless process.L i n x o f fers full EMC pre-compliance testing in our HP/Emco-equipped test center.F i n a l compliance testing is then perfo rmed by one of the many independent testing l a b o ra t o ries across the country.M a ny labs can also provide other certifications the product may require at the same time, such as UL, CLASS A/B, etc. Once yo u r completed product has passed, you will be issued an ID number which is then c l e a rly placed on each product manu fa c t u r e d . Questions regarding interpretations of the Pa rt 2 and Pa rt 15 rules or measurement procedures used to test intentional radiators should be addressed to: Fe d e ral Communications Commission Equipment Au t h o rization Division Customer Service Branch, MS 1300F2

7435 Oakland Mills Road

Columbia, MD 21046 Te l :(301) 725-1585 / Fa x :(301) 344-2050 E-Mail:l a b i n fo @ f c c . g ov I n t e rnational approvals are slightly more complex, although many modules are designed to allow all international standards to be met. If you are considering the ex p o rt of your product abroad, you should contact Linx Technologies to determ i n e the specific suitability of the module to your application. All Linx modules are designed with the approval process in mind and thus mu c h of the fru s t ration that is typically ex p e rienced with a discrete design is eliminated. A p p r oval is still dependent on many factors such as the choice of antennas, correct use of the frequency selected, and physical pack a g i n g .While some ex t ra cost and design effo rt are required to address these issues, the additional usefulness and profitability added to a product by RF makes the effo rt more than w o rt h w h i l e. N OT E :R M S e ries Modules are designed as component devices wh i ch re q u i re ex t e rnal components to function. The modules are intended to a l l ow for full Pa rt 15 compliance; howeve r,t h ey are not ap p roved by the FCC or any other age n cy wo rl dw i d e. The purchaser understands that ap p rovals may be re q u i red prior to the sale or operation of the dev i c e,a n d agrees to utilize the component in ke eping with all laws gove rning its o p e ration in the country of operat i o n .

ACHIEVING A SUCCESSFUL RF I M P L E M E N TAT I O N Adding wireless capabilities brings an exciting new dimension to any product.It also means that additional e f fo rt and commitment will be needed to bring the product successfully to marke t .By utilizing Linx RF modules the design and approval process will be greatly simplified. It is important, howeve r, to have an o b j e c t i ve view of the steps necessary to insure a successful RFi n t e gra t i o n .Since the capabilities of each customer va ry widely it is difficult to recommend one particular design path, but most projects fo l l ow steps similar to those shown at the ri g h t . In rev i ewing this sample design path you may notice that Linx offers a va riety of serv i c e s, such as antenna design, and FCC prequalification, that are unusual for a high-volume component m a nu fa c t u r e r. These serv i c e s, along with an exceptional level of technical support, are offe r e d 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 offe r, you will not only surv i ve implementing RF, but you may even find the process enjoya bl e. T Y P I C A LS T E P SF O R I M P L E M E N T I N GR F H E L P F U LA P P L I C AT I O NN O T E SF R O ML I N X 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 d e l i ver the maximum possible perfo rm a n c e. As you proceed with your design you may wish to obtain one or more of the fo l l owing application notes, which address in depth key areas of RF design and application of Linx products. 0 0 5 0 0 Antennas: Design, Application, Per f o rm a n c e 0 0 1 3 0 Modulation techniques for low-cost RF data links 0 0 1 2 5 Considerations for operation in the 260 Mhz to 470 Mhz band 0 0 1 0 0 RF 101: Information for the RF challenged 0 0 1 1 0 Understanding the per f o rmance specifications of r e c e i v e r s 0 0 1 4 0 The FCC Road: Part 15 from concept to appr o v a l

00150 Use and design of T-Attenuation Pads

N O T E# LINX APPLICA T I O NN O T ET I T L E

U . S . H e a d q u a rt e rs : LINX TECHNOLOGIES, INC. 575 S.E. ASHLEY P L A C E GRANTS PASS, OR 97526 PHONE: (541) 471-6256 FAX: (541) 471-6251 h t t p : / / w w w. l i n x t e c h n o l o g i e s . c o m Linx Technologies is continually striving to improve the quality and function of its products; for this reason, we reserve the right to make changes without notice. The info rm a t i o n contained in this Data Sheet is believed to be accurate as of the time of publ i c a t i o n . Specifications are based on representative lot samples. Values may va ry from lot to lot and are not guara n t e e d .Linx Technologies makes no guara n t e e, wa r ra n t y, or representation regarding the suitability of any product for use in a specific application. None of these dev i c e s is intended for use in applications of a critical nature where the safety of life or property is at ri s k .The user assumes full liability for the use of product in such applications. 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 o riginal product purchase pri c e. Some devices described in this publication are patented. Under no circumstances shall any user be conveyed any license or right to the use or ownership of these patents. D i s cl a i m e r © 2000 by Linx Te ch n o l ogi e s ,I n c. The stylized Linx l ogo ,L i n x ,and “ Wi reless made Simple” a re the t ra d e m a rks of Linx Te ch n o l ogi e s ,I n c. P rinted in U. S. A .