SLOS732G June   2011  – March 2020 TRF7960A

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  Delayed Transmission With CRC (0x13)
      6. 6.13.6  Delayed Transmission Without CRC (0x12)
      7. 6.13.7  Transmit Next Time Slot (0x14)
      8. 6.13.8  Block Receiver (0x16)
      9. 6.13.9  Enable Receiver (0x17)
      10. 6.13.10 Test Internal RF (RSSI at RX Input With TX On) (0x18)
      11. 6.13.11 Test External RF (RSSI at RX Input With TX Off) (0x19)
      12. 6.13.12 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  ISO14443B TX Options Register (0x02)
          2. 6.14.1.2.2  ISO14443A High-Bit-Rate and Parity Options Register (0x03)
          3. 6.14.1.2.3  TX Timer High Byte Control Register (0x04)
          4. 6.14.1.2.4  TX Timer Low Byte Control Register (0x05)
          5. 6.14.1.2.5  TX Pulse Length Control Register (0x06)
          6. 6.14.1.2.6  RX No Response Wait Time Register (0x07)
          7. 6.14.1.2.7  RX Wait Time Register (0x08)
          8. 6.14.1.2.8  Modulator and SYS_CLK Control Register (0x09)
          9. 6.14.1.2.9  RX Special Setting Register (0x0A)
          10. 6.14.1.2.10 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 TRF7960A 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

6.7.1.1 Internal RSSI – Main and Auxiliary Receivers

Each receiver path has its own RSSI block to measure the envelope of the demodulated RF signal (subcarrier). Internal Main RSSI and Internal Auxiliary RSSI are identical except that they are connected to different RF input pins. The Internal RSSI is intended for diagnostic purposes to set the correct RX path conditions.

The Internal RSSI values can be used to adjust the RX gain settings or decide which RX path (main or auxiliary) provides the greater amplitude and, hence, to decide if the MUX may need to be reprogrammed to swap the RX input signal. The measuring system latches the peak value, so the RSSI level can be read after the end of each receive packet. The RSSI register values are reset with every transmission (TX) by the reader. This guarantees an updated RSSI measurement for each new tag response.

The Internal RSSI has 7 steps (3 bit) with a typical increment of approximately 4 dB. The operating range is 600 mVpp to 4.2 Vpp with a typical step size of approximately 600 mV. Both RSSI values "Internal Main" and "Internal Aux" RSSI are stored in the RSSI Levels and Oscillator Status register (0x0F).

Figure 6-2 shows the nominal relationship between the input RF peak level and the RSSI value.

TRF7960A digital_internal_rssi_slos732.gifFigure 6-2 Digital Internal RSSI (Main and Auxiliary) Value vs RF Input Level

This RSSI measurement is done during the communication to the Tag; this means the TX must be on. Bit 1 in the Chip Status Control register (0x00) defines if internal RSSI or the external RSSI value is stored in the RSSI Levels and Oscillator Status register 0x0F. Direct command 0x18 is used to trigger an internal RSSI measurement.