SCPS270B August   2020  – November 2023 TCA4307

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Switching Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Hot bus insertion
      2. 7.3.2 Pre-charge voltage
      3. 7.3.3 Rise time accelerators
      4. 7.3.4 Bus ready output indicator
      5. 7.3.5 Powered-off high impedance for I2C and I/O pins
      6. 7.3.6 Supports clock stretching and arbitration
      7. 7.3.7 Stuck bus recovery
    4. 7.4 Device Functional Modes
      1. 7.4.1 Start-up and precharge
      2. 7.4.2 Bus idle
      3. 7.4.3 Bus active
      4. 7.4.4 Bus stuck
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
        1. 8.2.1.1 Series connections
        2. 8.2.1.2 Multiple connections to a common node
        3. 8.2.1.3 Propagation delays
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
      4. 8.2.4 Typical Application on a Backplane
        1. 8.2.4.1 Design Requirements
        2. 8.2.4.2 Detailed Design Procedure
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power Supply Best Practices
      2. 8.3.2 Power-on Reset Requirements
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.1 Overview

The TCA4307 is a hot-swappable I2C bus buffer that supports I/O card insertion into a live backplane without corruption of the data and clock buses. Control circuitry prevents the backplane from being connected to the card until a stop command or bus idle condition occurs on the backplane without bus contention on the card. When the connection is made, this device provides bidirectional buffering, keeping the backplane and card capacitances isolated. During insertion, the SDA and SCL lines are pre-charged to 1 V to minimize the current required to charge the parasitic capacitance of the device.

The TCA4307 has stuck bus recovery, which will automatically disconnect the bus if it detects that SDAOUT or SCLOUT are low for about 40 ms. Once the bus is disconnected, the device will automatically generate up to 16 pulses on SCLOUT to attempt to free the bus from the device which is holding it low.

When the I2C bus is idle, the TCA4307 is put into shutdown mode by setting the EN pin low. When EN is high, the TCA4307 resumes normal operation. It also includes an open drain READY output pin, which indicates that the backplane and card sides are connected together. When READY is high, the SDAIN and SCLIN are connected to SDAOUT and SCLOUT. When the two sides are disconnected, READY is low.