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18 November 1996

                        Multiplexer Module (TX2A/TX4A)

                                                                 MUX-17

4.  Installation and Use of the 4 Channel Multiplexer Module

4.1 Power Supply

4.1.1 Supply Requirements

Note:

The Multiplexer must not be supplied by Switched Mode Power Supplies (SMPS).   This
is because most SMPS operate at frequencies around 50 kHz.  The harmonics of the
generated field can interfere with the TIRIS receiver.  Therefore only use linear power
supplies, or SMPS with a fundamental operating frequency of 200 kHz or higher.

Noise from power supplies or noise on the interface lines can interfere with the RF Module’s
receiver.  Therefore, if the application requires it, it may be necessary to place additional filters in
series to the supply and interface lines.  For more details refer to RF Module Operating Manual.

In order to guarantee full RF Module performance, the power supplies should fulfill the
specifications for ripple voltage given in Table 7.

Table 7: Power Supply Ripple Specifications

Supply type

Maximum allowed
Ripple Voltage

Allowed Ripple Frequency

Unregulated VCL supply

30 mVrms

0 to 100 kHz maximum
(sinusoidal)

4.2 Antenna Requirements

The transmit antenna for the RF Module (which is used to charge up the transponder) is a coil
(see figure 3), this coil is part of the antenna resonant circuit of the RF Module.

In order to achieve the high voltages at the antenna resonant circuit and thus high field strength at
the antenna for charge-up (transmit) function, the antenna coil must have a high quality factor.
The recommended quality factor for proper operation is listed in table 8.  The quality factor of the
antenna is decreased when the Multiplexer is used, a maximum resistance of 200 mOhms is
added per channel, which reduces the quality factor of TIRIS Standard antennas to about 55 (the
original quality factor is approximately 100).

For proper operation of the transmitter and receive function, the antenna has to be tuned to the
resonance frequency f_TX.  For a detailed description of the antenna resonance tuning procedure,
see the RF Module Operating Manual.

To ensure that the antenna can be tuned to resonance with the connected RF Module, the antenna
inductance can only vary within the limits given in table 8.

Содержание RI-MOD-TX2A

Страница 1: ...Texas Instruments Registration and Identification System Multiplexer Module RI MOD TX2A discontinued RI MOD TX4A discontinued Reference Manual 11 06 21 034 18 November 1996...

Страница 2: ...plexer Module to the S25x0 has been included Texas Instruments reserves the right to change its products or services at any time without notice TI provides customer assistance in various technical are...

Страница 3: ...Supply 17 4 1 1 Supply Requirements 17 4 2 Antenna Requirements 17 4 3 Connecting Cable 18 4 4 Antenna Resonance Tuning 18 Figures Figure 1 Top View 7 Figure 2 Block Diagram 7 Figure 3 Configuration...

Страница 4: ...Multiplexer Module TX2A TX4A 18 November 1996 MUX 4...

Страница 5: ...g For product and ordering numbers of RF Module Antennas Control Modules combinations of these and Accessories please contact your local TIRIS Application Center The Module RI MOD TX2A is the 2 channe...

Страница 6: ...Control Module or a customer designed control unit are Low Power Schottky TTL and HCMOS Logic compatible The Multiplexer includes circuitry to reduce crosstalk of transmit function There are four conn...

Страница 7: ...TX RX antenna 4 TX RX antenna 1 TX RX antenna 2 TX RX antenna 3 Figure 1 Top View The Multiplexer switches the selected antenna to the RF Module The Multiplexer switches both the transmit and receive...

Страница 8: ...t Signals CSA CSB and Enable The Multiplexer has built in voltage regulators to supply the logic part and the MOS FET drivers with regulated voltage The input supply voltage must be connected to the p...

Страница 9: ...with the RF Module As the Multiplexer does not include the feature to tune the antennas individually to resonance the tuning has to be done in such a way that the optimum reading performance is achiev...

Страница 10: ...pletely switched off because there is still reasonable coupling via the parasitic capacitance of the MOSFET switch As the TIRIS receiver is very sensitive the small voltage which is coupled via this c...

Страница 11: ...e RFM antenna terminals via connector J3 Table 4 lists the pin function for ground post J6 Table 5 shows the logic switching of the active channel All connectors are accessible from the top Table 1 J1...

Страница 12: ..._OUT2 IN OUT Switched antenna signal switched to ground GNDTX when active Connected to TX RX antennas 6 ANT IN OUT Antenna resonator signal Connected to TX RX antennas 7 A_OUT1 IN OUT Switched antenna...

Страница 13: ...ed When it is closed all TX RX channels are enabled Default J2 closed J5 This jumper is used to connect the antenna terminal GNDTX pin 2 of connector J4 to the Multiplexer ground GND When using the Mu...

Страница 14: ...ed into a housing it must be guaranteed by proper design or cooling that the internal temperature does not exceed the absolute maximum ratings CAUTION Exceeding absolute maximum ratings may lead to pe...

Страница 15: ...signals CSA CSB and Enable signal J2 2 4 5 0 V Fan In Low Power Schottky compatible fan in of signals CSA CSB and Enable signal Iin 400 A 1 3 4 Timing Characteristics Symbol Parameter min typ max Unit...

Страница 16: ...ements given in figure 8 have a tolerance of 0 25 m J1 1 J2 J5 J6 8 1 J3 2 1 J7 85 09 90 17 5 08 5 08 15 49 85 54 130 81 135 89 74 01 64 00 95 25 J4 Figure 8 Module Layout and Dimensions Table 6 Size...

Страница 17: ...age Allowed Ripple Frequency Unregulated VCL supply 30 mVrms 0 to 100 kHz maximum sinusoidal 4 2 Antenna Requirements The transmit antenna for the RF Module which is used to charge up the transponder...

Страница 18: ...tandard Antennas when used together with the Multiplexer 55 4 3 Connecting Cable We recommend that the cable between the RFM and the Multiplexer is low resistive for example RF Litz wire 120 x 0 1 mm...

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