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

6.8 Oscillator Section

The 13.56-MHz oscillator is controlled by the Chip Status Control register (0x00) and the EN and EN2 signals. The oscillator generates the RF frequency for the RF output stage and the clock source for the digital section. The buffered clock signal is available at pin 27 (SYS_CLK) for external circuits. B4 and B5 inside the Modulation and SYS_CLK register (0x09) can be used to divide the external SYS_CLK signal at pin 27 by 1, 2, or 4.

Typical start-up time from complete power down is in the range of 3.5 ms.

During Power Down Mode 2 (EN = 0, EN2 = 1) the frequency of SYS_CLK is switched to 60 kHz (typical).

The 13.56-MHz crystal must be connected between pin 30 and pin 31. The external shunt capacitors values for C1 and C2 must be calculated based on the specified load capacitance of the crystal being used. The external shunt capacitors are calculated as two identical capacitors in series plus the stray capacitance of the TRF7960A and parasitic PCB capacitance in parallel to the crystal.

The parasitic capacitance (CS , stray and parasitic PCB capacitance) can be estimated at 4 to 5 pF (typical).

As an example, using a crystal with a required load capacitance (CL) of 18 pF, the calculation is as follows (see Figure 6-4):

C1= C2 = 2 × (CL – CS) = 2 × (18 pF – 4.5 pF) = 27 pF

Place a 27-pF capacitor on pins 30 and 31 to ensure proper crystal oscillator operation.

TRF7960A crystal_bd_slos732.gifFigure 6-4 Crystal Block Diagram

Table 6-5 shows the minimum characteristics recommended for any crystal used with TRF7960A.

Table 6-5 Minimum Crystal Recommendations

PARAMETER SPECIFICATION
Frequency 13.56 MHz
Mode of operation Fundamental
Type of resonance Parallel
Frequency tolerance ±20 ppm
Aging <5 ppm/year
Operation temperature range –40°C to 85°C

As an alternative, an external clock oscillator source can be connected to pin 31 to provide the system clock, and pin 30 can be left open.