SLOS757G December   2011  – March 2020 TRF7962A

PRODUCTION DATA.  

  1. 1Device Overview
    1. 1.1 Features
    2. 1.2 Applications
    3. 1.3 Description
    4. 1.4 Application Block Diagram
  2. 2Revision History
  3. 3Device Characteristics
    1. 3.1 Related Products
  4. 4Terminal Configuration and Functions
    1. 4.1 Pin Diagrams
    2. 4.2 Signal Descriptions
  5. 5Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Electrical Characteristics
    5. 5.5 Thermal Resistance Characteristics
    6. 5.6 Switching Characteristics
  6. 6Detailed Description
    1. 6.1  Functional Block Diagram
    2. 6.2  Power Supplies
    3. 6.3  Supply Arrangements
    4. 6.4  Supply Regulator Settings
    5. 6.5  Power Modes
    6. 6.6  Receiver – Analog Section
      1. 6.6.1 Main and Auxiliary Receiver
      2. 6.6.2 Receiver Gain and Filter Stages
    7. 6.7  Receiver – Digital Section
      1. 6.7.1 Received Signal Strength Indicator (RSSI)
        1. 6.7.1.1 Internal RSSI – Main and Auxiliary Receivers
        2. 6.7.1.2 External RSSI
    8. 6.8  Oscillator Section
    9. 6.9  Transmitter - Analog Section
    10. 6.10 Transmitter - Digital Section
    11. 6.11 Transmitter – External Power Amplifier or Subcarrier Detector
    12. 6.12 Communication Interface
      1. 6.12.1 General Introduction
      2. 6.12.2 FIFO Operation
      3. 6.12.3 Parallel Interface Mode
      4. 6.12.4 Reception of Air Interface Data
      5. 6.12.5 Data Transmission to MCU
      6. 6.12.6 Serial Interface Communication (SPI)
        1. 6.12.6.1 Serial Interface Mode Without Slave Select (SS)
        2. 6.12.6.2 Serial Interface Mode With Slave Select (SS)
      7. 6.12.7 Direct Mode
    13. 6.13 Direct Commands from MCU to Reader
      1. 6.13.1  Command Codes
      2. 6.13.2  Reset FIFO (0x0F)
      3. 6.13.3  Transmission With CRC (0x11)
      4. 6.13.4  Transmission Without CRC (0x10)
      5. 6.13.5  Transmit Next Time Slot (0x14)
      6. 6.13.6  Block Receiver (0x16)
      7. 6.13.7  Enable Receiver (0x17)
      8. 6.13.8  Test Internal RF (RSSI at RX Input With TX On) (0x18)
      9. 6.13.9  Test External RF (RSSI at RX Input With TX Off) (0x19)
      10. 6.13.10 Register Preset
    14. 6.14 Register Description
      1. 6.14.1 Register Overview
        1. 6.14.1.1 Main Configuration Registers
          1. 6.14.1.1.1 Chip Status Control Register (0x00)
          2. 6.14.1.1.2 ISO Control Register (0x01)
        2. 6.14.1.2 Protocol Subsetting Registers
          1. 6.14.1.2.1 TX Pulse Length Control Register (0x06)
          2. 6.14.1.2.2 RX No Response Wait Time Register (0x07)
          3. 6.14.1.2.3 RX Wait Time Register (0x08)
          4. 6.14.1.2.4 Modulator and SYS_CLK Control Register (0x09)
          5. 6.14.1.2.5 RX Special Setting Register (0x0A)
          6. 6.14.1.2.6 Regulator and I/O Control Register (0x0B)
        3. 6.14.1.3 Status Registers
          1. 6.14.1.3.1 IRQ Status Register (0x0C)
          2. 6.14.1.3.2 Collision Position and Interrupt Mask Registers (0x0D and 0x0E)
          3. 6.14.1.3.3 RSSI Levels and Oscillator Status Register (0x0F)
        4. 6.14.1.4 Test Registers
          1. 6.14.1.4.1 Test Register (0x1A)
          2. 6.14.1.4.2 Test Register (0x1B)
        5. 6.14.1.5 FIFO Control Registers
          1. 6.14.1.5.1 FIFO Status Register (0x1C)
          2. 6.14.1.5.2 TX Length Byte1 Register (0x1D) and TX Length Byte2 Register (0x1E)
  7. 7Applications, Implementation, and Layout
    1. 7.1 TRF7962A Reader System Using SPI With SS Mode
      1. 7.1.1 General Application Considerations
      2. 7.1.2 Schematic
    2. 7.2 System Design
      1. 7.2.1 Layout Considerations
      2. 7.2.2 Impedance Matching TX_Out (Pin 5) to 50 Ω
      3. 7.2.3 Reader Antenna Design Guidelines
  8. 8Device and Documentation Support
    1. 8.1 Getting Started and Next Steps
    2. 8.2 Device Nomenclature
    3. 8.3 Tools and Software
    4. 8.4 Documentation Support
    5. 8.5 Support Resources
    6. 8.6 Trademarks
    7. 8.7 Electrostatic Discharge Caution
    8. 8.8 Export Control Notice
    9. 8.9 Glossary
  9. 9Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.2.2 Impedance Matching TX_Out (Pin 5) to 50 Ω

The output impedance of the TRF7962A when operated at full power out setting is nominally 4 + j0 Ω (4 Ω real). This impedance must be matched to a resonant circuit, and TI recommends a matching circuit from 4 Ω to 50 Ω, as commercially available test equipment (for example, spectrum analyzers, power meters, and network analyzers) are 50-Ω systems. See Figure 7-2 and Figure 7-3 for an impedance match reference circuit. This section explains how the values were calculated.

Starting with the 4-Ω source, Figure 7-2 and Figure 7-3 shows the process of going from 4 Ω to 50 Ω by showing it represented on a Smith Chart simulator (available from http://www.fritz.dellsperger.net/). The elements are grouped together where appropriate.

TRF7962A impedence_matching_circuit_slos732.gifFigure 7-2 Impedance Matching Circuit

This yields the following Smith Chart simulation.

TRF7962A impedence_matching_smith_chart_slos732.pngFigure 7-3 Impedance Matching Smith Chart

Resulting power out can be measured with a power meter, spectrum analyzer with power meter function, or other equipment capable of making a "hot" measurement. Take care to observe maximum power input levels on test equipment and use attenuators whenever available to avoid any possibility of damage to expensive equipment. Table 6-3 lists the expected output power levels under various operating conditions.