Texas Instruments TCA4307DGKR

The TCA4307DGKR is a hot-swappable I²C bus buffer produced by Texas Instruments. This device is designed to support the insertion of I/O cards into a live backplane without causing corruption to the data and clock lines. It features control circuitry that prevents the backplane-side I²C lines from connecting to the card-side I²C lines until a stop command or bus idle condition is detected on the backplane, ensuring no bus contention on the card. The TCA4307 provides bidirectional buffering, isolating the backplane and card capacitances, and includes a 1-V precharge on all SDA and SCL lines to minimize current requirements during live insertion.

• Supports bidirectional data transfer of I²C bus signals.
• Operating power-supply voltage range of 2.3 V to 5.5 V.
• T_A ambient air temperature range of -40 °C to 125 °C.
• Stuck bus recovery featuring automatic bus recovery.
• 1-V Precharge on all SDA and SCL lines prevents corruption during live insertion.
• Accommodates standard mode and fast mode I²C devices.
• Supports clock stretching, arbitration, and synchronization.
• Powered-off high-impedance I²C pins.
• Includes an open drain READY output pin indicating the connection status between backplane and card sides.
• Supports shutdown mode by setting the EN pin low to reduce power consumption.

• Servers
• Enterprise Switching
• Telecom switching equipment
• Base stations
• Industrial automation equipment

1. What is the primary function of the TCA4307?

   The TCA4307 is a hot-swappable I²C bus buffer designed to support I/O card insertion into a live backplane without data corruption.

2. What is the operating temperature range of the TCA4307?

   The operating temperature range is -40°C to 125°C.

3. What is the power-supply voltage range for the TCA4307?

   The power-supply voltage range is 2.3 V to 5.5 V.

4. How does the TCA4307 handle stuck bus conditions?

   The TCA4307 features stuck bus recovery, which automatically disconnects the bus if SDAOUT or SCLOUT are low for about 40 ms and generates up to 16 pulses on SCLOUT to reset the bus.

5. What is the purpose of the READY output pin?

   The READY pin is an open drain output indicating whether the backplane and card sides are connected and ready for traffic.

6. How does the TCA4307 minimize disruptions during hot bus insertion?

   The TCA4307 uses a 1-V precharge circuit on the SDA and SCL lines to minimize the current required to charge the parasitic capacitance during insertion.

7. Does the TCA4307 support clock stretching and arbitration?

   Yes, the TCA4307 supports full clock stretching and arbitration without lockup.

8. How can the TCA4307 be put into shutdown mode?

   The TCA4307 can be put into shutdown mode by setting the EN pin low, reducing power consumption.

9. What types of I²C devices does the TCA4307 accommodate?

   The TCA4307 accommodates standard mode and fast mode I²C devices.

10. What is the significance of the rise-time accelerators in the TCA4307?

    The rise-time accelerators allow the use of weaker pull-up resistors, lowering system-level power consumption and VOLs.