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HP SERIES-II RECEIVER MODULE DESIGN GUIDE
DESCRIPTION:
The HP Series-II receiver module is designed for the
cost-effective, high-performance wireless transfer of
analog or digital data, in the popular 902-928MHz
band. The receiver offers eight selectable channels
and, when paired with an HP Series-II transmitter, is
capable of receiving analog and digital information
for distances up to 1000 feet (under optimum
conditions). The receiver employs an advanced
microprocessor-controlled synthesized architecture.
Like all Linx modules, the HP Series-II requires no
tuning and in most cases no external RF
components
(except
integration straightforward even for engineers
lacking previous RF experience.
FEATURES:
8 Binary Selectable Reception Frequencies
Exceptional Sensitivity (-95dBm @ 10
High Serial Data Rate (50Kbps max.)
Direct Serial Interface
Fully Qualified Data Output
Wide-Range Audio-Capable Analog Output (50Hz-25KHz)
Cost-Effective
No External RF Components Required (Except Antenna)
Manufacturing-Friendly SIP-Style Packaging
Precision-Synthesized Frequency Reference
Wide Supply Range (2.7-16V DC)
Receive Signal Strength (RSSI) and Powerdown Pins
No Production Tuning
APPLICATIONS INCLUDE:
Continuous Data Transfer
Home/Industrial Automation
Wireless Networking
Remote Control
Remote Access
Remote Monitoring/Telemetry
Fire/Security Alarms
Long-Range RFID
High-Quality Wireless Audio
Analog Signal Transfer
General Wire Elimination
Revised 2/1/00
an
antenna),
making
H
P
IGH
ERFORMANCE
RF MODULE
RXM-900-HP-II
Figure 1: Physical Package
-5
BER typical)
ORDERING INFORMATION
PART #
MDEV-900-HP-II Evaluation Kit 900 MHz
TXM-900-HP-II
RXM-900-HP-II
0.35
DESCRIPTION
Transmitter 900 MHz
Receiver 900 MHz
Page 1
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Table of Contents
Related Manuals for Linx RXM-900-HP-II
Summary of Contents for Linx RXM-900-HP-II
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Page 1: Ordering Information
1000 feet (under optimum conditions). The receiver employs an advanced microprocessor-controlled synthesized architecture. Like all Linx modules, the HP Series-II requires no tuning and in most cases no external RF components (except... -
Page 2: Specifications
SPECIFICATIONS ABOUT THESE MEASUREMENTS The performance parameters listed below are based on module operation at 25°C from a 5VDC supply unless otherwise noted. It is recommended all ground pins be connected to the ground-plane. The pin marked N/C has no physical connection and is designed only to add support. -
Page 3: Typical Performance Graphs
TYPICAL PERFORMANCE GRAPHS 2.40 2.00 V/div 5.00 V/div +/-1.0 V 2.10 1.80 1.50 RSSI Out 1.20 0.90 0.60 0.30 Data Out 0.00 2.00 ms/div 6.57000000 ms 2.58 V -110 -100 -80 PIN (dBm) Figure 4: Receiver Turn-on Time Figure 5: Receiver RSSI -90 -91 -92 -93 -94 -95 -96 -97 -98 -99 -100 PIN (dBm) Figure 6: RSSI Response Time... - Page 4 HP-II RECEIVER MANUAL TIMING CONSIDERATIONS There are five major timing considerations the engineer must be aware of when designing with the HP Series-II receiver. These are shown in figure 8A below, and are labeled T through T Parameter Description Min. Max.
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Page 5: Pin Descriptions
PIN DESCRIPTIONS: PIN# Name Equivalent CTK Description RF In RF Input/ 50-ohm RF Input 50Ω Antenna Input Analog Ground No Connection Channel Select 0 Channel Select 1 Channel Select 2 Power down (Active Low) 470K Received Signal RSSI RSSI Strength Indicator Digital Ground Voltage Input 2.7-16V 1V p-p Analog Output... -
Page 6: Theory Of Operation
The user-supplied antenna is connected at pin 1 (see Figure 1). The HP-II-RXM RF port is matched to 50 ohms to support interface to commonly available antennas such as those manufactured by Linx. The RF signal coming in from the antenna is filtered by a SAW (surface acoustic wave) filter. - Page 7 If you are at all familiar with RF devices you may be concerned about specialized layout requirements. Fortunately, because of the care taken by Linx in the layout of the module’s PCB, integrating an HP Series-II receiver into your design is very straightforward. By adhering carefully to a few basic design and layout rules, you can enjoy a trouble-free path to RF success.
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Page 8: Microstrip Details
The HP-II receiver should, as much as reasonably possible, be isolated from all other components on your PCB. Specifically, high-frequency circuitry such as crystal oscillators should be kept as far away as possible from the HP-II receiver. If the receiver is to be mounted parallel to the board, it should be laid over so that the side with the crystal is closest to the PC board and the RF side is facing away from the PC board. -
Page 9: Power Considerations
POWER CONSIDERATIONS POWER SUPPLY The user must provide a clean source of power to the receiver to ensure proper operation. In an FM receiver, power-supply noise will manifest itself as AM and FM noise in the receiver circuitry, reducing the overall sensitivity of the receiver. -
Page 10: Channel Selection
NOTE: READ THIS IF YOU ARE GOING TO PERIODICALLY POWER-DOWN RECEIVER!! A common method of reducing receiver power consumption is to turn the receiver off via the PDN pin for some time interval and wake the receiver periodically to check for the presence of a transmitted signal. - Page 11 Another area of consideration is that of data structure or protocol. If you are not familiar with the considerations for sending serial data in a wireless environment you will want to review Linx application note #00160 (Considerations for sending data with the HP Series-II). These issues should be clearly understood prior to commencing a significant design effort.
- Page 12 MAX 232 DB-9F 220 uF 4.7 uF 4.7 uF 4.7 uF Channel 3 Position Select DIP Switch 4.7 uF Figure 17: Typical Application - RS-232 Interface 3-Position Channel DIP Switch Select Output to User 390K OSC1 OSC2 HT694 8-Position DIP Switch Address Select Figure 18: Typical Application - Remote-Control Receiver PROXIMITY OPERATION...
- Page 13 RSSI CIRCUIT The HP Series-II receivers are equipped with an on-board Received-Signal- Strength-Indicator (RSSI) circuit. RSSI is useful to check for channel occupation, and interference as well as signal strength determination. The RSSI circuit provides a DC voltage which is logarithmically proportional to the incoming signal strength present at the RF input pin.
- Page 14 Linx documentation for hints on what the problem might be. If all else fails, contact Linx and discuss your design with an application engineer.
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Page 15: Antenna Considerations
Linx. Our low-cost antenna line is designed to ensure maximum performance and compliance with Part 15 attachment requirements. The purpose of the following sections is to give you a basic idea of some of the considerations involved in the design and selection of antennas. - Page 16 Antenna resonance should not be confused with antenna impedance. The difference between resonance and impedance is most easily understood by considering the value of VSWR at its lowest point. The lowest point of VSWR indicates the antenna is resonant, but the value of that low point is determined by the quality of the match between the antenna, the transmission line, and the device it is attached to.
- Page 17 In reviewing this section it is important to recognize that each antenna style will produce widely varying results based on the specific design execution and optimization. Additional information can be found in Linx application notes #00500, #00100, #00125 and #00140. Whip Style A whip-style antenna provides exceptional performance and is easy to integrate.
- Page 18 A helical is a wire coil usually wound from steel, copper or Helical Style brass. This antenna is very efficient given its small size. The helical is an excellent choice for products requiring good range-performance and a concealed internal antenna element.
- Page 19 The FCC requires that antennas designed for use on Part 15 products be either permanently attached, or utilize a unique and proprietary connector not available to the general public. Linx offers a full line of connectors designed to comply with these requirements. To insure the continued compliance of these connectors, details are not available on our website.
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Page 20: Legal Considerations
Linx Technologies to determine the specific suitability of the module to your 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. -
Page 21: Helpful Application Notes From Linx
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. NOTE # LINX APPLICATION NOTE TITLE... - Page 22 Power Conversion Tables For 50Ω System dBmV mVRMS mVpp 0.000 -3.0 0.000 0.000 0.000 12.0 11.2 0.001 17.0 10.0 20.0 0.003 22.0 12.6 17.8 35.6 0.0l 0 27.0 22.4 31.6 63.2 0.032 32.0 39.8 56.2 112.5 0.100 37.0 70.7 100.0 200.0 0.316 42.0...
- Page 23 MISMATCH CONVERSION TABLE VSWR Insertion Power Power Loss Transmitted Reflected (dB) 17.391 -6.87 20.57% 79.43% 11.610 -5.35 29.21% 70.79% 8.724 -4.33 36.90% 63.10% 6.997 -3.59 43.77% 56.23% 5.848 -3.02 49.88% 50.12% 5.030 -2.57 55.33% 44.67% 4.419 -2.20 60.19% 39.81% 3.946 -1.90 64.52% 35.48%...
- Page 24 Data Sheet 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. Linx Technologies makes no guarantee, warranty, or representation regarding the suitability of any product for use in a specific application.
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