SRF305 User Manual 3 November 2014 U080.0.5-SRF305 2014 Cervis, Inc. Module SRF305 This document is the property of Cervis, Inc. and cannot be copied, modified, e-mailed, or reproduced without the express prior written consent of Cervis, Inc. Cervis, Inc. reserves the right to change this manual or edit, delete, or modify any information without prior notification. FCC Statements 15.19 Two Part Warning This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions:
(1)
(2) This device may not cause harmful interference and This device must accept any interference received, including interference that may cause undesired operation. 15.21 Unauthorized Modification NOTICE: The manufacturer is not responsible for any unauthorized modifications to this equipment made by the user. Such modifications could void the users authority to operate the equipment. 15.27 Special Accessories This device is supplied with special accessories that include an RF adapter cable and antenna. These special accessories must be used with the device. It is the responsibility of the user to use the needed special accessories supplied with the equipment. 15.105(b) Note:
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense. Industry Canada Statements RSS-GEN 7.1.2 Transmitter Antenna / Antenne de L'metteur Under Industry Canada regulations, this radio transmitter may only operate using an antenna of a type and maximum (or lesser) gain approved for the transmitter by Industry Canada. To reduce potential radio interference to other users, the antenna type and its gain should be so chosen that the equivalent isotropically radiated power (e.i.r.p.) is not more than that necessary for successful communication. Conformment la rglementation d'Industrie Canada, le prsent metteur radio peut fonctionner avec une antenne d'un type et d'un gain maximal (ou infrieur) approuv pour l'metteur par Industrie Canada. Dans le but de rduire les risques de brouillage radiolectrique l'intention des autres utilisateurs, il faut choisir le type d'antenne et son gain de sorte que la puissance isotrope rayonne quivalente (p.i.r.e.) ne dpasse pas l'intensit ncessaire l'tablissement d'une communication satisfaisante. This radio transmitter 7955A-SRF305 has been approved by Industry Canada to operate with the antenna types listed below with the maximum permissible gain and required antenna impedance for each antenna type indicated. Antenna types not included in this list, having a gain greater than the maximum gain indicated for that type, are strictly prohibited for use with this device. Le prsent metteur radio 7955A-SRF305 a t approuv par Industrie Canada pour fonctionner avec les types d'antenne numrs ci-dessous et ayant un gain admissible maximal et l'impdance requise pour chaque type d'antenne. Les types d'antenne non inclus dans cette liste, ou dont le gain est suprieur au gain maximal indiqu, sont strictement interdits pour l'exploitation de l'metteur. Approved Antenna List / Liste Antenne Approuv Manufacturer Antenna-Factor/Linx Tech RFM Or Equivalent Alfa Or Equivalent Part Number ANT-2.4-uSP OMNI242R Or Equivalent ARSN19TNC Or equivalent Stock Number Gain Impedance B141 BB3-07
+3.8dBipeak
+3dBipeak 50 Ohm 50 Ohm BB3-08
+9dBipeak 50 Ohm RSS-GEN 7.1.3 Notice / Dlai This device complies with Industry Canada licence-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device. Le prsent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorise aux deux conditions suivantes : (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage radiolectrique subi, mme si le brouillage est susceptible d'en compromettre le fonctionnement. User Manual Table of Contents Table of Contents .......................................................................................................................... i List of Figures ............................................................................................................................... i List of Tables ................................................................................................................................. i Cervis Inc. Safety Precautions ................................................................................................... 1 1.0 SRF305 Introduction ............................................................................................................ 2 1.1 SRF305 Features ............................................................................................................... 2 1.2 SRF305 Pinouts ................................................................................................................ 4 2.0 SRF305 Installation ............................................................................................................ 16 3.0 SRF305 Tune-up Procedure .............................................................................................. 16 4.0 SRF305 Electrical Characteristics .................................................................................... 16 4.1 Supply Voltage and Current .......................................................................................... 16 4.2 Operating Current ........................................................................................................... 17 4.3 SPI Interface .................................................................................................................... 17 5.0 SRF305 RF Characteristics ............................................................................................... 17 5.1 General RF Information .................................................................................................. 17 5.2 RF Exposure Considerations ........................................................................................ 17 List of Figures Figure 1. SRF305 RF section Front .............................................................................................. 4 Figure 2. SRF305 RF section Back ............................................................................................... 4 Figure 3. 07440305-2H-U-12R (SRF305 Type 1), component side, shield, internal label, external antenna connector ........................................................................................ 6 Figure 4. 07610304-2H-U SRF305 Type 2,, component side, shield, internal label, external antenna connector ....................................................................................................... 8 Figure 5. 07440306-2H-U-12R, SRF305 Type 3,, component side, shield and internal label, external antenna connector ...................................................................................... 10 Figure 6. 14001300-2H, SRF305 Type 4, component side and with shield. ........................... 11 Figure 7. HH-2H10 (left) implemented with Type 4 module, compared to HH-2H06 with non-
modular RF circuit integrated into the application PCB. In both applications the RF circuit under the shield is identical. .................................................................. 13 Figure 8. PG-2H implemented with Type 4 module, antenna mounting and RF transmission line are part of the application PCB. ....................................................................... 14 Figure 9. SRF305 Type 1 module, antenna mounting and RF transmission line are part of the module PCB. ........................................................................................................ 15 List of Tables Table 1. 07440205 PCB (SRF305 Type 1) plug-in connector HDR1 ........................................ 4 Table 2. 07610204 PCB (SRF305 Type 2) plug-in connector J1 ............................................. 7 Table 3. 07440206 PCB (SRF305 Type 3) plug-in connector HDR1 ....................................... 8 Table 4. 14001200 PCB (SRF305 Type 4) connections .......................................................... 11 Table 5. Antenna/user separations for various application conditions. ............................... 18 Definitions:
2014Cervis, Inc. i Module SRF305 A final product ready to operate, containing and RTM RTM: Receive Transmit Module Host Application:
SAR: Specific Absorption Rate Internal Antenna:
External Antenna:
Informed person:
Uninformed person: Has NOT been properly trained in the operation of the host application and/or an operator, partially or fully outside the host application enclosure at any time. gain <= +3.9dB (SAR tested), non-directional, not accessible to or removable gain <= +9dBi (SAR tested), non-directional, accessible to or removable by by an operator, fully within the host application enclosure at all times. Has been properly trained in the operation of the host application. may not be aware that the host application is operating nearby. ii U080.0.5-SRF305 User Manual User Manual Notes and Observations 2014Cervis, Inc. iii User Manual Cervis Inc. Safety Precautions Read and follow all instructions. Failure to abide by Safety Precautions may result in equipment failure, loss of authority to operate the equipment, and personal injury. Use and maintain proper wiring. Follow equipment manufacturer instructions. Improper, loose, and frayed wiring can cause system failure, equipment damage, and intermittent operation. Changes or modifications made to equipment not expressly approved by the manufacturer will void the warranty. Owner/operators of the equipment must abide by all applicable Federal, State, and Local laws concerning installation and operation of the equipment. Failure to comply could result in penalties and could void user authority to operate the equipment. Turn off the module power before attempting any maintenance. This will prevent accidental operation of the controlled machinery. Do not allow liquid to enter the module enclosure. Do not use high pressure equipment to clean the module. Operate and store units only within the specified operation and storage temperatures defined in the Specifications of this document. 1.0 SRF305 Introduction Module SRF305 The SRF305 RTM is based on a single-chip radio frequency (RF) transceiver integrated circuit (RFIC), an Atmel AT86RF231. The RT module also contains an external RF transmit power amplifier plus low noise RF receive preamplifier integrated circuit (PA/LNA), an RFaxis RFX2401C. The SRF305 RTM is intended to be integrated into Cervis Inc. products, providing a wireless RF connectivity option. The SRF305 RTM operates in the 2.45 GHz ISM band, using spread spectrum modulation with a maximum conducted RF transmit power of +19.95dBm (per RF emission test report) at the antenna port. The RFIC generates RF signals compliant with the Zigbee standard, IEEE 802.15.4-2006. The spread spectrum technique is direct sequence (DSSS), the modulation method is orthogonal quadrature phase shift keying (O-QPSK). The RFIC has internal control registers that the host application can access via a serial peripheral (SPI) bus. These registers control all aspects of how the RFIC is used, which must be compliant with all applicable rules and regulations. The SR305 RTM is interoperable various various other Cervis Inc. RTMs that use the same modulation and message data structure. Interoperability with non-Cervis RTMs, while possible, is not supported. The SRF305 RTM is most commonly applied in half-duplex master/slave systems: the master transmits a message to a slave, the slave transmits a reply to the master. Other operating modes are possible, provided that applicable rules and regulations are not violated. The SRF305 RTM may be realized in various PCB shapes, some with non-RF circuits applicable to the requirements of particular host applications. Variations include:
LOBSRF305 Type 1:
LOBSRF305 Type 2:
LOBSRF305 Type 3:
LOBSRF305 Type 4:
The Type 1, 2 and 3 RTM variants are mechanically configured for use in mobile applications, with internally or externally mounted antennas. Type 4 modules are mechanically configured for use in portable applications with internally mounted antennas, although they may be used with externally mounted antennas. Type 4 modules may be used in mobile applications as needed. In all applications of all type of modules, it is required that proper engineering practices be followed to ensure that RF emissions remain compliant with all applicable regulations and SAR limitations are not violated. Any changes that affect the nature of RF emissions or RF exposure limits may require additional testing and/or new approvals. large mezzanine (RF emission and SAR tested, pictured) mini-module (RF emission tested, pictured) small mezzanine (RF emission tested, pictured) postage stamp (RF emission tested, pictured) 1.1 SRF305 Features 2405-2480 MHz Operation 5 MHz Selectable Channel Orthogonal Quadrature Phase Shift Keying (O-QPSK) Direst Sequence Spread Spectrum (DSSS) 250 kbps Data Rate (tested) 500 kbps Data Rate (capable, not tested) 1000 kbps Data Rate (capable, not tested) 2000 kbps Data Rate (capable, not tested) 2 U080.0.5-SRF305 User Manual User Manual IEEE 802.15.4-2006 messaging Up to +19.95dBm Output Power (Per RF emission report) Use with a variety of approved, supplied internal and external antennas SPI host interface Simple power requirements Compliant will all FCC (and equivalent IC) requirements for a modular transmitter LOBSRF305, the following elements confirm that LOBSRF305 complies with the definition of a modular transmitter:
a. The radio elements of the modular transmitter have their own shielding. The physical In accordance with FCC Rule Part 15.212 for the product certified under FCC ID:
crystal and tuning capacitors are located internal to the shielded radio elements. b. The modular transmitter has buffered modulation/data inputs to ensure that the module will comply with part 15 requirements under conditions of excessive data rates or over-modulation. c. The modular transmitter has its own power supply regulation. d. The modular transmitter complies with the antenna and transmission system requirements of 15.203, 15.204(b) and 15.204(c). hen installed in the host application, the antenna is either be permanently attached or employs a unique antenna coupler (at all connections between the module and the antenna, including the cable). The professional installation provision of 15.203 is not applicable to modules but can apply to limited modular approvals under paragraph (b) of this section. e. The modular transmitter has been tested in a stand-alone configuration, i.e., the module must not be inside another device during testing for compliance with part 15 requirements. When the transmitter module is not battery powered it complies with the AC line conducted requirements found in 15.207. AC or DC power lines and data input/output lines connected to the module do not contain ferrites, unless they will be marketed with the module (see 15.27(a)). The length of these lines shall be the length typical of actual use or, if that length is unknown, at least 10 centimeters to insure that there is no coupling between the case of the module and supporting equipment. Any accessories, peripherals, or support equipment connected to the module during testing shall be unmodified and commercially available (see 15.31(i)). f. The modular transmitter is equipped with a permanently affixed label displaying its FCC identification number. g. The modular transmitter complies with any specific rules or operating requirements that ordinarily apply to a complete transmitter and the manufacturer must provide adequate instructions along with the module to explain any such requirements. A copy of these instructions must be included in the application for equipment authorization. h. The modular transmitter must comply with any applicable RF exposure requirements in its final configuration. 2014Cervis, Inc. 3 Module SRF305 Figure 1. SRF305 RF section Front Figure 2. SRF305 RF section Back 1.2 SRF305 Pinouts Table 1-4 show the pinouts and interface signals on several alternative packaging options for the SRF305 RTM:
Table 1. 07440205 PCB (SRF305 Type 1) plug-in connector HDR1 Pin 1 2 3 4 5 6 7 8 9 Name SPI_CLK GND MISO MOSI RF_SLP_TR
/RF_RST
/RF_CS RF_IRQ RF_PAEN Signal SPI data clock in ground SPI data out SPI data in RFIC control RFIC reset RFIC chip select RFIC interrupt output Enable external PA Details Clock from SPI master Low impedance ground Data from SPI slave Data from SPI master Multipurpose control signal from master Low from SPI master Low from SPI master Input to SPI master High from SPI master 4 U080.0.5-SRF305 User Manual User Manual 10 RF_HGM/BPA GND GND DISPLAYCS
/RFEE_CS (reserved) DISPLAYRS DISPLAYBLANK reserved reserved DISPLAYRST reserved LED_6 LED_7 LED_4 LED_5 LED_2 LED_3 LED_0 LED_1 GND GND
+24VDC
+5VDC
+3.3VDC 11 12 13*
14*
15*
16*
17 18 19*
20 21*
22*
23*
24*
25*
26*
27*
28*
29 30 31*
32*
33 34*
Enable external LNA or Read BPA jumper ground ground Display chip select EE chip select Display register select Display on/off reserved reserved Display reset reserved Indicator Indicator Indicator Indicator Indicator Indicator Indicator Indicator ground ground
+3.0-30V
+3.0-30V
+3.3V Function not used in SRF305 Input to SPI master Low impedance ground Low impedance ground Low from SPI master Low from SPI master From SPI master From SPI master reserved reserved Low from SPI master reserved High from SPI master High from SPI master High from SPI master High from SPI master High from SPI master High from SPI master High from SPI master High from SPI master Low impedance ground Low impedance ground Power indicator LED Power indicator LED Power indicator LED, RF & logic power. Low noise 150mA max. Power indicator LED REVBAT
*Not required for SRF305
+3.0-30V The 07440305-2H-x-12R PCB assembly, SRF305 Type1, includes all circuits and features required for properly implementing the SRF305 RTM. A variety of approved antennas may be used. The PCB also provides circuits and mounting for various optional non-RF features of use to a host application, including:
12 indicator LEDs (default installation) LED/LCD display module (future use) 2014Cervis, Inc. 5 Module SRF305 Figure 3. 07440305-2H-U-12R (SRF305 Type 1), component side, shield, internal label, external antenna connector 6 U080.0.5-SRF305 User Manual User Manual Table 2. 07610204 PCB (SRF305 Type 2) plug-in connector J1 Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Name SPI_CLK GND MISO MOSI RF_SLP_TR
/RF_RST
/RF_CS RF_IRQ RF1_3VD GND RF1_3VA GND RF_PAEN RF_HGM/BPA GND Signal SPI data clock in ground SPI data out SPI data in RFIC control RFIC reset RFIC chip select RFIC interrupt output
+3.0-3.3V ground
+3.0-3.3V ground Enable external PA Enable external LNA or Read BPA jumper ground Details Clock from SPI master Low impedance ground Data from SPI slave Data from SPI master Multipurpose control signal from master Low from SPI master Low from SPI master Input to SPI master RF & logic power. Low noise 125mA max. Low impedance ground RF analog power. Low noise 25mA max. Low impedance ground High from SPI master Function not used in SRF305 Input to SPI master Low impedance ground The 07610304-2H-U PCB assembly, SRF305 Type 2, is similar to the approved 07440305-
2H-x-12R PCB assembly, except for elimination of non-RF circuits and a change in the shape and connector to accommodate use in host applications that utilize the form-factor of the 07610304-2H-x. Except for some minor differences outside the shielded RF section, the operation of 07610304-2H-U is compliant with the SRF305 modular approval, as demonstrated by testing. The RF connection of 076100304-2H-U is always via a coaxial cable and unique connector. Choice of an approved antenna for internal or external mounting depends on the design of the specific host application. The 07610304-2H-U PCB assembly includes all circuits and features required for properly implementing the SRF305 RTM 2014Cervis, Inc. 7 Module SRF305 Figure 4. 07610304-2H-U SRF305 Type 2,, component side, shield, internal label, external antenna connector Table 3. 07440206 PCB (SRF305 Type 3) plug-in connector HDR1 Pin 1*
2 Name
/RFEE_CS (reserved) RF_SLP_TR Signal EE chip select RFIC control 3 4 5 6 7 8 9 10 11 12 13*
14*
15*
16*
17*
18*
19*
20*
21
/RF_RST RF_IRQ
/RF_CS RF_PAEN RF_HGM/BPA SPI_CLK MOSI MISO GND GND LED_7 LED_6 LED_5 LED_4 LED_3 LED_2 LED_1 LED_0 GND RFIC reset RFIC interrupt output RFIC chip select Enable external PA Enable external LNA or Read BPA jumper SPI data clock in SPI data in SPI data out ground ground Indicator Indicator Indicator Indicator Indicator Indicator Indicator Indicator ground Details Low from SPI master Multipurpose control signal from master Low from SPI master Input to SPI master Low from SPI master High from SPI master Function not used in SRF305 Input to SPI master Clock from SPI master Data from SPI master Data from SPI slave Low impedance ground Low impedance ground High from SPI master High from SPI master High from SPI master High from SPI master High from SPI master High from SPI master High from SPI master High from SPI master Low impedance ground 8 U080.0.5-SRF305 User Manual User Manual 22 23*
24*
25 26*
GND REVBAT
+5VDC
+3.3VDC
+24VDC
*Not required for SRF305 ground
+3.0-30V
+3.0-30V
+3.3V
+3.0-30V Low impedance ground Power indicator LED Power indicator LED Power indicator LED, RF & logic power. Low noise 150mA max. Power indicator LED The 07440306-2H-x-12R PCB assembly, SRF305 Type 3, is similar to the approved 07440305-2H-x-12R PCB assembly, except for a change in the shape and connector to accommodate use in host applications that utilize the form-factor of the 07440306-2H-x-12R. Except for some minor differences outside the shielded RF section, the operation of 07420305-
2H-x-12R is compliant with the SRF305 modular approval, as demonstrated by testing. The 07440306-2H-x-12R PCB assembly includes all circuits and features required for properly implementing the SRF305 RTM. The PCB also provides circuits and mounting for various optional non-RF features of use to a host application, including:
12 indicator LEDs (default installation) 2014Cervis, Inc. 9 Module SRF305 Figure 5. 07440306-2H-U-12R, SRF305 Type 3,, component side, shield and internal label, external antenna connector 10 U080.0.5-SRF305 User Manual User Manual Table 4. 14001200 PCB (SRF305 Type 4) connections Pin 1 2 3 4 5 Name SPI_CLK GND MISO MOSI RF_SLP_TR 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
/RF_RST
/RF_CS RF_IRQ RF1_3VD GND RF1_3VA GND RF_PAEN RF_HGM/BPA GND GND GND GND GND RF Port GND Signal SPI data clock in ground SPI data out SPI data in RFIC control RFIC reset RFIC chip select RFIC interrupt output
+3.0-3.3V ground
+3.0-3.3V ground Enable external PA Enable external LNA or Read BPA jumper ground ground ground ground ground Antenna connection ground Details Clock from SPI master Low impedance ground Data from SPI slave Data from SPI master Multipurpose control signal from master Low from SPI master Low from SPI master Input to SPI master RF & logic power. Low noise 25mA max. Low impedance ground RF analog power. Low noise 125mA max. Low impedance ground Active high from SPI master Function not used in SRF305 Input to SPI master Low impedance ground Low impedance ground Low impedance ground Low impedance ground Low impedance ground 50 Ohm RF In/Out port Low impedance ground The 14001300-2H PCB assembly, SRF305 Type 4, is similar to the SRF305 Type 2 RTM, except for elimination of PCB structure required for connectors, where the physical connection to the host application is now made by directly soldering the RTM to the host PCB. The SRF305 Type RTM depends on the host application for all connections to approved antennas. Figure 6. 14001300-2H, SRF305 Type 4, component side and with shield. 2014Cervis, Inc. 11 Module SRF305 Type 4 Module Application Engineering:
The Type 4 module requires that the host application provide suitable mechanical and electrical mounting, control and power signals, an approved antenna that is properly mounted a proper RF transmission line to connect the RF port on the module to the antenna feed port, and all SAR-related safety spacings are maintained. An example of a typical Type 4 module properly integrated into a portable host application PCB is shown in Figure 7 (left) and Figure 8. RF exposure spacing is enforced when the PCB is assembled into the enclosure. Mounting: This module must be mounted on a ground plane that extends at least 8mm from the RF shield edges. All connections between the host application and the module are to be soldered. Note: 8mm is the minimum ground plane extent measured from the RF shield on a Type 1 module. Power and Control Signals: All connections listed in Table 4 must be made. RF Transmission Line:
The RF connection between the module RF port and the antenna feed port must have a nominal 50 Ohm impedance, have low insertion loss and be as short as practical. Microstrip transmission line may be implemented as part of the host PCB. Coaxial cable may be used to connect to an external antenna. Coaxial cable can be attached either with a suitable connector or may be directly soldered to where the host PCB attaches to the RF port of the module. If a replaceable external antenna is used the user-accessible external connection must be a unique type such as RP-TNC, RP-SMA, etc. Antennas: Low gain internal antennas may be located anywhere within a host application, provided that the design is properly engineered and safety spacings are maintained. Certain antenna types, such as dipoles, do not need any ground plane to work properly, just a proper RF transmission connection the RF port of the module. Other common antenna such as those made using PCB traces typically require attachment to a ground plane to work properly. The ground plane should extend without significant interruptions from the ground point(s) of the antenna by at least wavelength (30mm for 2450 MHz), and may be shared with other ground plane areas, including that used to mount the RT module. Examples of host applications using the Type 4 module are shown in Figures 8 and 9. Compared to a similar Type 1 module in Figure 9, the important RF features are essentially the same. The modules are similarly equipped and configured for using an internal PCB-trace style antenna with a nominal +3dBi maximum gain. The yellow (not to scale) rectangles show the internal antenna mounting relative to the RF shield (which defines the active RF circuit area). The orange rectangles (not to scale) indicate where microstrip PCB transmissions lines are implemented in the host or module PCBs. The length of the transmission line is not critical, but it should be no longer than needed in order to minimize losses. A coaxial cable could be used. The red rectangles (not to scale) indicate the 8mm copper ground plane surrounding the RF shield. The copper thickness is not critical. The green rectangles (not to scale) indicate the copper ground plane area required for proper operation of the installed antenna. The copper thickness is not critical. In Figures 8 and 9 the illustrated antenna is a variant of the planar PCB-F PCB trace antenna. As such, it requires a ground plane area extending at least wavelength from the connected edge of the antenna, approximately 31mm at 2450 MHz. Alternative antennas such as a dipole do not require any ground plane. The RF engineer must consider antenna ground requirements when designing the host application. 12 U080.0.5-SRF305 User Manual User Manual Figure 7. HH-2H10 (left) implemented with Type 4 module, compared to HH-2H06 with non-
modular RF circuit integrated into the application PCB. In both applications the RF circuit under the shield is identical. 2014Cervis, Inc. 13 Module SRF305 Figure 8. PG-2H implemented with Type 4 module, antenna mounting and RF transmission line are part of the application PCB. 14 U080.0.5-SRF305 User Manual User Manual Figure 9. SRF305 Type 1 module, antenna mounting and RF transmission line are part of the module PCB. 2014Cervis, Inc. 15 2.0 SRF305 Installation Module SRF305 When integrating an SRF305 RTM into a host application, the user must provide all text in the FCC Statements and Industry Canada Statements in the host applications user manual (see Forward Material). The text must not be modified in any way and presented in a conspicuous manner that the end user can be reasonably expected to access. When integrating the SRF305 RTM into host application hardware, the user must properly connect all the circuits identified in Table 1 to suitable host application signals. The host application firmware must properly control the RTM to ensure that emitted RF signals comply with all applicable regulatory approvals. The SRF305 RTM is always provided with an approved type of antenna, either internal fixed or external replaceable. If a fixed internal antenna is provided as part of the RTM, the on-board coaxial cable connectors are not populated. If the module is assembled for use with an external antenna, one of the on-board coaxial cable connector positions will be populated. The choice of the particular type of coaxial connector that is installed will be decided by the designer of the host application. The on-board connector is not accessible to users, so it does not need to be unique. When provided, external replaceable antennas always have a unique connector such as: RP-
N, U.FL/IPEX, RP-SMA, RP-BNC or RP-TNC. A suitable coaxial cable jumper with appropriate connectors must be used to connect the SRF305 RTM external antenna port to the external antenna. The details of a particular host application will affect the design of the jumper coax, but the external connector must always be of an acceptable unique type. The coaxial cable used to make the jumper between the RTM and the external antenna mounting position must be suitable for use at 2450 MHz and have 50 Ohm impedance. Low loss cable such as RG-316 is suggested, although signal loss will be small if the jumper length is short. External coaxial cables may be used to help mount the replaceable external antenna in a more useful location. Such cable must have appropriate unique connectors and must be made from low loss 50 Ohm coaxial cable. Cables equivalent to LMR-195 are suitable for lengths up to 30 feet. Longer cables must have suitably lower signal loss, typically using larger cable such as LMR240, LMR-300, or larger (or equivalent). At some point, a practical limit is reached where losses in extension cables negate any gains from relocating the antenna. 3.0 SRF305 Tune-up Procedure There is no tune-up procedure. The module contains no adjustable components. Proper RF operation of the module is verified during the manufacturing process using suitable equipment and methods. 4.0 SRF305 Electrical Characteristics 4.1 Supply Voltage and Current The SRF305 RTM by itself requires a low noise regulated 3.0-3.3 VDC source that can provide 150mA without losing regulation. The module does not provide under-voltage, over-
voltage, or reverse polarity protection so use caution when applying power. It is the responsibility of the host application to provide an appropriate source of 3.0-3.3V adequate to power the RTM, plus any other non-RF circuits that may also be implemented on the same PCB. All external connection points designate as signal GND should be connected to the host application GND circuit so as to maintain a low resistive and reactive impedance as practical. 16 U080.0.5-SRF305 User Manual User Manual The PCB hosting the RTM should be fabricated with low impedance copper floods that connect to GND. The SRF305 RTM can safely operate with a supply voltage over the range of 3.0-3.3V with minimal changes in RF performance. 4.2 Operating Current The SRF305 RTM has four primary operating conditions that draw differing amounts of current from to 3.0-3.3V power source:
Off PLL_ON RX TX PA is reduced because the full +19.95dBm RF output power is not required. RFIC is powered down, minimal load RFIC is ready to transmit or receive, ~5mA RFIC is receiving a message, ~12mA RFIC is transmitting, ~15-100mA, depending on TX output power In TX mode the operating current may be less than the maximum if the drive to the external 4.3 SPI Interface The SPI interface between the RFIC (slave) and the host application (master) microcontroller requires four signals:
SCLK The serial data clock from the SPI master. Must be less than 8 MHz. MOSI Serial data from the SPI master. MISO Serial data from the SPI slave. RF_CS Chip select from the SPI master. The SPI controller setting must be established by the host application microcontroller to be compatible with the SPI interface timing specified by the RFIC data sheet. 5.0 SRF305 RF Characteristics 5.1 General RF Information The RFIC used in the SRF305 RTM implements RF modulation modes and timings in compliance with IEEE 802.15.4-2006. The RFIC implements additional proprietary RF modulation modes. Details may be found in the AT86RF231 RFIC data sheet. The SRF305 general spread spectrum scheme is DSSS. The modulation type is O-QPSK. The data rate is 250kbps. Separation distances stated in this section are based on SAR test results from the SRF305 5.2 RF Exposure Considerations Type 1 RT module, SAR.20131205 from RF Exposure Lab, submitted as SRF305 FCC Rev A_s.pdf. The minimum measured safe distances, specifically stated in the blue box on page 1, are 3mm for an internal antenna and 8mm for an external antenna. Laboratory measurements indicate that the primary radiation comes from the antenna and is minimal from other parts of the module or host application. Proper application of SRF305 Types 1, 2 3 and 4 will result similar RF emission characteristics. 2014Cervis, Inc. 17 Module SRF305 Mobile and portable host applications incorporating SRF305 Type 1, 2, 3 or 4 RT modules Mobile host applications incorporating SRF305 Type 1, 2, 3 or 4 RTMs with external (fully or A:
with internal (entirely within the enclosure) antennas must ensure that users are physically separated from the antenna by at least 3mm. B:
partially exposed outside the enclosure) antennas must ensure that users are physically separated from the antenna by at least 8mm, per the SAR test report. This separation requirement may met by including an installation guideline in the user manual that states that the any external antenna must be located at least 20cm from any space likely to be occupied by an uninformed person. C:
Portable host applications incorporating SRF305 Type 1, 2, 3 or 4 RTMs with external (fully or partially exposed outside the enclosure) antennas must ensure that informed users are physically separated from the antenna by at least 8mm. This separation requirement may met by including in the user manual a guideline indicating the normal operating pose. D:
or 4 RTMs are responsible for ensuring compliance with RF exposure limitations and any other applicable regulations. Changes may require new testing and approval submission. that include any SRF305 RTM and antenna combination. and the required separation distances. Mobile applications with external antennas assume that an uninformed person may be nearby, thus the 20cm separation guidance rather than the tested safe separation of 8mm. Module Type These separation requirements must be included in end-user manuals for host applications Any parties creating mobile and portable host applications incorporating SRF305 Type 1, 2, 3 The following table summarizes the antennas that may be used with the SRF305 RT modules Portable (informed) Mobile Mobile (uninformed) Portable Internal <= +3dBi Antenna External <= +9dBi Antenna Internal <= +3dBi Antenna External <= +9dBi Antenna 1 2 3 4
> 3mm
> 3mm
> 3mm
> 3mm
> 8mm
> 8mm
> 8mm
> 8mm
> 3mm
> 3mm
> 3mm
> 3mm
> 20cm
> 20cm
> 20cm
> 20cm Table 5. Antenna/user separations for various application conditions. 18 U080.0.5-SRF305 User Manual User Manual Visit our Web site at: www.cervisinc.com 2014 Cervis, Inc. All rights reserved. Content is subject to change without notice. 2014Cervis, Inc. 19