Features and Benefits

  • Bidirectional Buffer* for SDA and SCL Lines Increases Fanout
  • Prevents SDA and SCL Corruption During Live Board Insertion and Removal From Backplane
  • Logic Threshold ENABLE Input
  • Isolates Input SDA and SCL Lines from Output
  • Compatible with I2C, I2C Fast Mode and SMBus Standards (Up to 400kHz Operation)
  • 1V Precharge on all SDA and SCL Lines
  • Supports Clock Stretching, Arbitration and Synchronization
  • 5V to 3.3V Level Translation
  • High Impedance SDA, SCL Pins for VCC = 0V, VCC2 = 0V
  • Small 8-Lead DFN and MSOP Packages

Product Details

The LTC4300A-3 hot swappable 2-wire bus buffer allows I/O card insertion into a live backplane without corruption of the data and clock busses. When the connection is made, the LTC4300A-3 provides bidirectional buffering, keeping the backplane and card capacitances isolated. Rise-time accelerator circuitry allows the use of weaker DC pull-up currents while still meeting rise-time requirements. During insertion, the SDA and SCL lines are precharged to 1V to minimize bus disturbances.

The LTC4300A-3 provides level translation between 3.3V and 5V supplies. The backplane and card can both be powered with supplies ranging from 2.7V to 5.5V. The LTC4300A-3 also incorporates a CMOS threshold ENABLE pin which forces the part into a low current mode and isolates the card from the backplane. When driven to VCC, the ENABLE pin sets normal operation.

The LTC4300A-3 is available in the MSOP and 3mm × 3mm DFN packages.

*Patent pending.


  • Hot Board Insertion
  • Servers
  • Capacitance Buffer/Bus Extender
  • Desktop Computer

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Tools & Simulations


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Product Recommendations

LTC4300A-3 Companion Parts

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Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.

PCN-PDN Information

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