Texas Instruments 2000 series User manual

A TEXAS INSTRUMENTS TECHNOLOGY
Series 2000 Reader SystemHigh Performance Reader Frequency ModuleRI-RFM-007B
Reference Guide
November 2002
SCBU022

A TEXAS INSTRUMENTS TECHNOLOGY
Series 2000 Reader System
High Performance Reader Frequency ModuleRI-RFM-007B
Reference Guide
Literature Number: SCBU022November 2002

Contents
Preface ............................................................................................................................... 5
1 Product Description ................................................................................................... 71.1 General ............................................................................................................... 81.2 Transmitter ........................................................................................................... 91.3 Receiver ............................................................................................................ 101.4 RFM Connectors and Jumpers .................................................................................. 10
2 Specifications .......................................................................................................... 152.1 Recommended Operating Conditions .......................................................................... 162.2 Dimensions ......................................................................................................... 19
3 Installation ............................................................................................................... 213.1 Power Supply Requirements .................................................................................... 223.2 Power Supply Connection ........................................................................................ 22
4 Associated Antenna Systems .................................................................................... 254.1 Antenna Requirements ........................................................................................... 264.2 Antenna Resonance Tuning ..................................................................................... 274.3 Tuning Procedure ................................................................................................. 27
5 Regulatory, Safety & Warranty Notices ....................................................................... 315.1 Regulatory Notes .................................................................................................. 325.1.1 FCC Notices (U.S.A) ..................................................................................... 325.1.2 CE Conformity (Europe) ................................................................................. 32
A Expanding Antenna Tuning Inductance Range ............................................................. 33
B Field Strength Adjustment ......................................................................................... 37
C Adjustment of Oscillator Signal Pulse Width ................................................................ 39
D Threshold Level Adjustment ...................................................................................... 41
E Transmitter Carrier Phase Synchronization (CPS) ........................................................ 43
F Noise Considerations ................................................................................................ 45
G Over Voltage Protection ............................................................................................ 47
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List of Figures
1-1 RFM Block Schematic ....................................................................................................... 81-2 Pulse Width Examples ...................................................................................................... 91-3 RFM Top View .............................................................................................................. 111-4 RFM Bottom View .......................................................................................................... 122-1 Mechanical Dimensions ................................................................................................... 193-1 External Ground Connection (GND to GNDP) ......................................................................... 234-1 Tuning Example Showing Increase of Total Tuning Capacity and Generated Field Strength (TypicalValues) ....................................................................................................................... 284-2 Flow Chart for Tuning the Antenna to Resonance ..................................................................... 29A-1 Circuit for Expanding Antenna Tuning Range to Lower Values ...................................................... 33A-2 Circuit for Expanding Antenna Tuning Range to Higher Values ..................................................... 34E-1 Distance Between Antennas (Top View) ................................................................................ 43F-1 Noise Testing Configuration .............................................................................................. 46G-1 Circuit for Overvoltage Protection ........................................................................................ 48
List of Tables
1-1 J1 Pin Functions ............................................................................................................ 121-2 J2 Pin Functions ............................................................................................................ 131-3 J4 Pin Functions ............................................................................................................ 131-4 J3 Pin Functions ............................................................................................................ 131-5 Antenna Connectors ....................................................................................................... 141-6 Transmitter Carrier Phase Synchronization (CPS) Dip Switch SW1 ................................................ 142-1 Operating Conditions ...................................................................................................... 162-2 Electrical Characteristics .................................................................................................. 172-3 Timing Characteristics ..................................................................................................... 182-4 Mechanical Parameters ................................................................................................... 183-1 Power Supply Ripple Specifications ..................................................................................... 224-1 Antenna Requirements .................................................................................................... 26A-1 Capacitor Values for Expanding Antenna Tuning Range to Lower Values ......................................... 34A-2 Capacitor Values Expanding Antenna Tuning Range to Higher Values ............................................ 35C-1 Oscillator Signal Pulse Width vs Resistor Value (Estimated Values) ............................................... 39E-1 Maximum Distances Between Antennas ................................................................................ 43F-1 Characteristics of Radiated and Conducted Noise .................................................................... 45
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PrefaceSCBU022 – November 2002
Fifth Edition – November 2002This manual describes the TI-RFid™ High Performance Reader Frequency Module RI-RFM-007B,hereafter referred to as the RFM.
Conventions
Certain conventions are used in order to display important information in this manual, these conventionsare:
WARNINGA WARNING IS USED WHERE CARE MUST BE TAKEN, OR ACERTAIN PROCEDURE MUST BE FOLLOWED, IN ORDER TOPREVENT INJURY OR HARM TO YOUR HEALTH.
CAUTION
This indicates information on conditions which must be met, or a procedurewhich must be followed, which if not heeded could cause permanent damage tothe RFM.
Note: Indicates conditions which must be met, or procedures which must be followed, to ensureproper functioning of the RFM.
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Trademarks
Trademarks
The TI-RFid logo and the words TI-RFid and Tag-it are trademarks or registered trademarks of TexasInstruments.
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Chapter 1SCBU022 – November 2002
Product Description
This chapter introduces the RFM component assemblies, showing the transmitter andreceiver sections and placement of key user-accessible components.
Topic .................................................................................................. Page
1.1 General ...................................................................................... 81.2 Transmitter ................................................................................ 91.3 Receiver ................................................................................... 101.4 RFM Connectors and Jumpers ................................................... 10
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1.1 General
PWM
TX
Oscillator
RX
demodulator
RXSS-
Interface
Antenna
Circuit
TX/RX
Antenna
RX
Amplifier
RXSS
threshold
ATI
Int
TX Power
Stage
CPS
TXCT-
RXDT
RXCK
ATI
6
Threshold
Demodulator
PWM Control Input
Overvoltage Protection
General
WARNINGCARE MUST BE TAKEN WHEN HANDLING THE RFM. HIGHVOLTAGE ACROSS THE ANTENNA TERMINALS, ALL ANTENNACOMPONENTS AND SOME PARTS OF THE PRINTED CIRCUITBOARD (PCB) COULD BE HARMFUL TO YOUR HEALTH. IF THEANTENNA INSULATION IS DAMAGED, THE ANTENNA SHOULDNOT BE CONNECTED TO THE RFM.
CAUTION
This product may be subject to damage by electrostatic discharge (ESD). Itshould be handled by ESD protected personnel at ESD secured workplacesonly. The transmitter power output stage can only operate with a limited dutycycle. Please pay attention to this whilst performing antenna tuning procedures.Ground pins GND and GNDP must be connected externally to avoid damage tothe unit.
The RFM is an integral part of the TI-RFid system. Coupled with a Control Module and an antenna, it isused for wireless identification of TI-RFid transponders. A block schematic is shown in Figure 1-1 .
Figure 1-1. RFM Block Schematic
The RFM contains all the analogue functions of a TI-RFid reading unit needed to send an energizingsignal via the antenna to initialize a TI-RFid transponder, to demodulate the received identification signaland to send the received data together with clock signals to a Control Module.
The RFM also sends the necessary programming and addressing signals to Read/Write and Multipagetransponders.
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1.2 Transmitter
Pulse width of 50% Pulse width of 12.5%
Transmitter
The data input and output lines, which are connected to a data processing unit, are low-power SchottkyTTL and HCMOS logic compatible.
The functions of the RFM are described in Section 1.2 .
The transmitter power stage is supplied with power via two separate supply lines VSP and GNDP.Because of the high current requirements for the transmitter power stage, these supply lines areseparated from the logic section supply lines and have two pins per line.
The ground pins for the logic section and the transmitter are not connected internally in order to avoidpossible problems with a high resistivity of GNDP pins and in order to increase flexibility when using longsupply lines. Pins GND and GNDP must be connected to each other externally. For more details, refer toSection 3.1 , Power Supply Connection.
The regulated transmitter power stage supply may vary between +7 V and +24 V. The supply lines VSPand VSL should be connected together when the supply voltage is +7 V or more. For details refer toChapter 2 , Specifications.
Note: The RFM has an in-built temperature protection circuit which sharply limits the transmitterpower stage output if an over-current situation or an over-temperature environmentcauses the temperature to exceed the allowed limits. After the device is switched off andhas time to recover (when the temperature drops again or the over-current situation isotherwise rectified) the unit reverts to normal operation when it is switched on again. Suchan occurrence is an indication that the RFM is not being operated within specification.
The transmit frequency (134.2 kHz) from the oscillator is fed to the pulse width modulator (PWM). Bychanging the value of a resistor, the PWM can set the pulse width ratio between 0% and 50%. For anexample of two different oscillator signal pulse widths see Figure 1-2 . Decreasing the 134.2 kHz frequencypulse width ratio decreases the generated transmit (charge-up) field strength.
It is therefore possible to adjust the generated field strength by selecting different pulse width ratios. Formore information about setting the field strength, refer to Appendix B , Field Strength Adjustment.
Figure 1-2. Pulse Width Examples
CAUTION
The RFM must not be operated in continuous transmit mode when operated atfull power output. For details please refer to Chapter 2 , Specifications. Whenusing pulse widths smaller than 50%, the RFM transmitter power stage works ina less efficient way. This leads to an increased power dissipation and thus tohigher temperature increase of the transmitter power stage, so ensure thatmore cooling is provided.
Note: If the RFM is going to be physically located within the antenna field, it may be necessaryto shield the module.
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1.3 Receiver
1.4 RFM Connectors and Jumpers
Receiver
The signal received from the transponder is a frequency shift keying (FSK) signal with typical low and highbit frequencies of 134.2 kHz and 123.2 kHz respectively. The signal is received from the antennaresonator, which is capacitively coupled to the receiver.
The signal RXCK is the reference clock signal to decode the RXDT data stream. The RXCK signalchanges from low to high level during each data bit and the RXDT signal is valid before and after thispositive slope for a certain time window. For more details refer to Table 2-3 , Timing Characteristics.
The receiver also has a built-in RF receive signal strength detector. The receive signal strength isindicated by the digital output RXSS-.
RXSS- becomes active ( logic low level) when the received RF signal strength exceeds a defined level.This threshold level can be adjusted with a potentiometer (R409) on the RFM. The potentiometer islocated near SW1 on the board. See Figure 1-3 , RFM Top View.
The RXSS- output is used for detection of other transmitting reading units and thus can be used forwireless read cycle synchronization of several reading units.
There are a number of connectors, jumpers and other components on the RFM available for use.
These are:
J1 Connector for supply voltages and interface signal lines to and from the RFMJ2 Connector for the (optional) Antenna Tuning Indicator (ATI), which can be used for easyantenna tuning during installation.J3 Connector for antenna resonance tuning, used to connect the required tuning capacitors.J4 Connector for field strength adjustment resistor and also direct access to receiver input.J5 Additional antenna damping Jumper.J6 Common-mode noise choke bypass.R409 RXSS noise level adjustment potentiometer.SW1 Default all on. (SW1/1 CPS setting see Appendix E .)ANT1/ANT2 (Two M3 screw connectors) Connect the transmit/receive (TX/RX) antenna to the RFM.
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RFM Connectors and Jumpers
The RFM is normally mounted from the underside utilizing appropriate spacers and M3 mounting bolts.
The top view of the RFM (without the normally fitted heatsink) is shown in Figure 1-3 . Connectors J2, J3,J4, J5, J6, R409, switch SW1 and the antenna terminals are accessible from the top.
Figure 1-3. RFM Top View
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ANT 1
ANT 2
5
3
1
3
1
1
3
5
7
9
11
13
15
· ·
· ·
· ·
· ·
· ·
· ·
· ·
· ·
· ·
· ·
· ·
· ·
· ·
6
4
2
4
2
2
4
6
8
10
12
14
16
· ·
· ·
· ·
· ·
· ·
· ·
· ·
J1
J2
J4
J3
14
12
10
8
6
4
2
13
11
9
7
5
3
1
RFM Connectors and JumpersThe bottom view of the RFM is shown in Figure 1-4 . The connectors J1, J2, J3 and J4 are accessible fromthe underside. J1 is the 16-pin module connector, this carries the supply voltage lines, the data, and thecontrol lines.
Figure 1-4. RFM Bottom View
Table 1-1 lists the pin functions for connector J1. The connector type is 16 pin, 2 row with 2.54 mm pinspacing.
Table 1-1. J1 Pin Functions
Pin# Signal Direction Description
1 GND IN Logic ground2 TXCT- IN Transmitter control input for activation of transmitter (active low, internal pull-up resistor)3 VSL IN Supply voltage for logic and receiver4 RXDT OUT Logic level compatible receiver data signal output5 RXSA IN/OUT Receiver signal strength adjust for RXSS- threshold level6 RXCK OUT Logic level compatible receiver clock output7 GNDP IN Transmitter power stage ground8 No connection9 GNDP IN Transmitter power stage ground10 RSTP OUT Analog receiver signal strength test pin11 VSP IN Supply voltage for transmitter power stage12 CPS_OUT OUT Carrier Phase Synchronization oscillator signal output13 VSP IN Supply voltage for transmitter power stage14 RXSS- OUT Receiver signal strength output (active low)15 No connection16 CPS_IN IN Carrier Phase Synchronization oscillator signal input
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RFM Connectors and Jumpers
CAUTION
The transmitter ground pins GNDP and logic ground pin GND must beconnected together externally. The RFM may be otherwise permanentlydamaged.
Table 1-2 lists the pin functions for the ATI connector J2: The connector type is a 6 pin, 2 row connectorwith 2.54 mm pin spacing.
Table 1-2. J2 Pin Functions
Pin
Signal Direction Description#
1 TXCT-R IN Transmitter control signal via resistor (active low)2 GND OUT Logic ground3 VD OUT Internal regulated logic supply voltage output4 F_OSC-R IN/OUT Pulse width modulated transmitter oscillator signal via resistor5 RXSS- OUT Receiver signal strength output (active low)6 F_ANT OUT Antenna resonance frequency output signal (open collector)
Table 1-3 lists the pin functions for the J4 pulse width adjustment connector. The connector type is 4 pin,2 row with 2.54 mm pin spacing.
Table 1-3. J4 Pin Functions
Pin# Signal Description
1 RX Analog transponder signal2 GNDA Ground antenna circuit3 Pulse width adjusting resistor connecting pin4 GND Logic ground
Table 1-4 lists the functions for connector J3. This is a 14 pin, 2 row connector with 2.54 mm pin spacing.
Table 1-4. J3 Pin Functions
Pin# Signal Description
1 ATC1 Antenna tuning capacitor 1 (weighted value 1)2 GNDA Ground antenna circuit3 ATC2 Antenna tuning capacitor 2 (weighted value 2)4 GNDA Ground antenna circuit5 ATC3 Antenna tuning capacitor 3 (weighted value 4)6 GNDA Ground antenna circuit7 ATC4 Antenna tuning capacitor 4 (weighted value 8)8 GNDA Ground antenna circuit9 ATC5 Antenna tuning capacitor 5 (weighted value 16)10 GNDA Ground antenna circuit11 ATC6 Antenna tuning capacitor 6 (weighted value 32)12 GNDA Ground antenna circuit13 AMTP Antenna circuit test point14 No connection
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RFM Connectors and Jumpers
Table 1-5 lists the pin functions for the antenna terminal connectors: Metric screws size M3 are used forconnection.
Table 1-5. Antenna Connectors
Signal Description
ANT1 Antenna resonator (capacitor side)ANT2 Antenna resonator (transformer side)
Jumper JP6 allows enabling and disabling of common noise filtering for EMI purposes. The default setting,with common noise filtering active, jumpers pins 2 and 3. A jumper between pins 1 and 2 bypassescommon noise filtering.
Table 1-6. Transmitter Carrier Phase Synchronization (CPS) Dip Switch SW1
Dip-Switch Position Description
On = RFM Master (default)1 ON
Off = RFM Slave2 ON Must be in ON Position3 ON Must be in ON Position
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Chapter 2SCBU022 – November 2002
Specifications
This chapter lists the recommended operating conditions, electrical and mechanicalcharacteristics and dimensions.
Topic .................................................................................................. Page
2.1 Recommended Operating Conditions .......................................... 162.2 Dimensions .............................................................................. 19
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2.1 Recommended Operating Conditions
I_VSP = P_VSP
V_VSP × Duty Cycle
where Duty Cycle = Power on time
Total Read Cycle Time
I_VSP = 20 W
24 V × 0.5 = 1.66 A Duty Cycle = 50 ms
100 ms = 0.5
I_VSP = 20 W
24 V × 0.625 = 1.33 A Duty Cycle = 50 ms
80 ms = 0.625
Recommended Operating Conditions
CAUTION
Exceeding recommended maximum ratings may lead to permanent damage ofthe RFM. The RFM must not be operated in continuous transmit mode whenoperated at full power output. Install suitable heatsinks when operating theRFM at pulse widths smaller than 50%.
Table 2-1 shows the recommended operating conditions.
Table 2-1. Operating Conditions
Symbol Parameter Min Typ Max Unit
V_VSP Supply voltage of transmitter power stage 7.0 12.0 24.0 V DCCurrent consumption of transmitter power stage - refer to the formulaI_VSP 1.0 1.7 Apeakbelow
Peak pulse power input to transmitter power stageP_VSP 20 W(I_VSP * V_VSP * Duty Cycle)V_ANT Antenna resonance voltage 250 380 VpeakV_ANT-25 Antenna resonance voltage (Pulse width setting ≤25%) 200 VpeakV_ANT-D1 Antenna resonance voltage for damping option using jumper JP3 50 60 VpeakV_ANT-ATI Minimum antenna resonance voltage for correct operation of ATI 25 VpeakV_VSL Supply voltage input for logic part 7.0 24.0 V DCI_VD External current load on internal regulated logic supply voltage output 1.0 mAT_oper Operating free-air temperature range -25 +70 °CT_store Storage temperature range -40 +85 °C
Note: Free-air temperature is the air temperature immediately surrounding the RFM module. Ifthe module is incorporated into a housing, it must be guaranteed by proper design orcooling that the internal temperature does not exceed the recommended operatingconditions.
In order to keep power consumption (P_VSP) below 20 W it is advisable to limit I_VSP. The maximumallowed value, dependent on the configuration, can be determined as follows (in the following examples asupply voltage of 24 V_VSP is used):
Example 1: Using Standard/Default Settings ( ≈10 read cycles/second)
Example 2: Configured to No Sync ( ≈12 read cycles/second)
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Recommended Operating ConditionsThe following methods can be used to measure the actual I_VSP value:1. Use a battery powered oscilloscope to measure the voltage drop across a 0.1 Ωresistor placed in theDCIN+ line, and then calculate the actual current using the formula I = V/R.2. If a battery powered oscilloscope is not available, measure the potential at both sides of the 0.1 Ωresistor (signal probe) with the GND probe at DCIN- and determine the potential difference.Ensure that the measured I_VSP value does not exceed the calculated value.
Table 2-2. Electrical Characteristics
Symbol Parameter Min Typ Max Unit
I_VSL Supply current for logic and receiver part in transmit and receive mode 14 18 22 mAViL Low level input voltage of TXCT- 0 0.4 0.8 VViH High level input voltage of TXCT- 2.4 5.0 VVoL Low level output voltage of RXDT and RXCK 0 0.4 0.8 VVoH High level output voltage of RXDT and RXCK 4.0 5.25 VVoL_R Low level output voltage of RXSS- 0.8 VVoH_R High level output voltage of RXSS- (see note below) 5.25 VFan-In Low power Schottky compatible fan-in of signals TXCT- (Iin = -400 µA) 1 -Input current for TXCT- signal, when the Accessory Module RI-ACC-ATI2I_IN-TXCT- 2.0 2.5 3.0 mAis connectedFan-Out Low power Schottky compatible fan-out of signals RXDT and RXCK 3 -FanOut_Rl Low power Schottky compatible fan-out of signal RXSS- (low level only) 1 -Low power Schottky compatible fan-out of signal RXSS- (high level only)FanOut_Rh
(see note below)l_J1 Cable length for connecting J1 of RFM to a Control Module using flat cable 0 0.5 2.0 mCable length for connecting the Carrier Phase Synchronization signall_CPS 0 1.0 5.0 mbetween two RFMsNumber of oscillator SLAVE RFMs, which can be driven from one oscillatorn_CPS 1 5 -MASTER RFMCommon Mode Noise reduction ratio for noise coupled to both antennaCom_Mode 20 dBterminals ANT1 and ANT2R_GND Decoupling resistor between GND and GNDP ( ±5%) 64.6 68 71.4 Ω
Note: RXSS- has an internal pull-up resistor of 10 k Ω. The parameter VoH_R therefore dependson application specific external components.
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Recommended Operating Conditions
Table 2-3. Timing Characteristics
Symbol Parameter Min Typ Max Unit
t_TX Transmit burst length for correct operation (see note below) 15 50 100 msDelay time from beginning of data bit at RXDT being valid to positive slopet_dtck 20 µsof RXCK signalt_dtvd Time for data bit of RXDT signal being valid after positive slope of RXCK 90 µst_ckhi Time for clock signal RXCK being high 55 µst_ri
Necessary rise and fall times for input signal TXCT- and TXCT-R 1 µst_fi
t_ro
Rise and fall time of output signals RXDT and RXCK 1 µst_fo
t_ro_R Rise time of output signal RXSS- (no external connection) 1 µst_fo Fall time of output signal RXSS- 1 µsPropagation delay time from positive slope of TXCT- to positive slope oftss_01Tl 500 1000 1500 µsRXSS- signal (maximum sensitivity)Propagation delay time from negative slope of TXCT- to negative slope oftss_10Tr 50 100 200 µsRXSS- signal (minimum sensitivity)Maximum time of short circuit between antenna terminals ANT1 and ANT2t_short 10 sand short circuit of ANT1 or ANT2 to GNDA
Note: Due to transponder parameters a minimum charge-up time of 15 ms is necessary.Decreasing charge-up time decreases read range by sending less energy to thetransponder.
CAUTION
The parameter t_short refers to a static short circuit of the antenna terminals.Shorting the antenna terminals during operation may cause permanent damageto the RFM.
Table 2-4. Mechanical Parameters
Parameter Typical Unit
Height including mounting bolts 44.0 ±1.5 mmWeight approx. 251 g
Note: The heatsink is connected to the antenna resonator ground GNDA. When connecting theheatsink to a housing, the heatsink must be insulated from the housing.
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2.2 Dimensions
70.36 mm
83 mm 1.0 mm
57.6 mm 1.0 mm
16.0 mm
+/- 1.0 mm
93 mm+/- 1.0mm
71.1mm
4.83 mm
+/- 1.0 mm
M3 Pressnuts
+/-
+/-
Dimensions
All measurements are in millimeters with a tolerance of ±0.5 mm unless otherwise noted.
Figure 2-1. Mechanical Dimensions
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Specifications 20 SCBU022 – November 2002Submit Documentation Feedback