Home Interface I2C & I3C ICs I2C & I3C level shifters, buffers & hubs

2-bit bidirectional 2.7- to 5.5-V hot swappable 400-kHz I2C/SMBus buffer

TCA4311 is not recommended for new designs
Although this product continues to be in production to support previous designs, we don't recommend it for new designs. Consider one of these alternates:
open-in-new Compare alternates
Similar functionality to the compared device
TCA4311A ACTIVE 2-bit bidirectional 2.7- to 5.5-V hot swappable 400-kHz I2C/SMBus buffer The TCA4311A is a p2p replacement for the TCA4311. There are enhanced features related to the TCA4311A, making it most robust.

Product details

Frequency (max) (MHz) 0.4 Rating Catalog Operating temperature range (°C) -40 to 85
Frequency (max) (MHz) 0.4 Rating Catalog Operating temperature range (°C) -40 to 85
SOIC (D) 8 29.4 mm² 4.9 x 6 VSSOP (DGK) 8 14.7 mm² 3 x 4.9
  • Operating Power-Supply Voltage Range of 2.7-V to 5.5-V
  • Supports Bidirectional Data Transfer of I2C Bus Signals
  • SDA and SCL Lines Are Buffered Which Increases Fanout
  • 1-V Precharge on All SDA and SCL Lines Prevents Corruption During Live Board Insertion and Removal From Backplane
  • SDA and SCL Input Lines Are Isolated From Outputs
  • Accommodates Standard Mode and Fast Mode I2C Devices
  • Applications Include Hot Board Insertion and Bus Extension
  • Low ICC Chip Disable of <1 μA
  • READY Open-Drain Output
  • Supports Clock Stretching, Arbitration, and Synchronization
  • Powered-Off High-Impedance I2C Pins
  • Open-Drain I2C Pins
  • Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
  • ESD Protection Exceeds JESD 22
    • 8000-V Human-Body Model (A114-A)
    • 200-V Machine Model (A115-A)
    • 1000-V Charged-Device Model (C101)

All trademarks are the property of their respective owners.

  • Operating Power-Supply Voltage Range of 2.7-V to 5.5-V
  • Supports Bidirectional Data Transfer of I2C Bus Signals
  • SDA and SCL Lines Are Buffered Which Increases Fanout
  • 1-V Precharge on All SDA and SCL Lines Prevents Corruption During Live Board Insertion and Removal From Backplane
  • SDA and SCL Input Lines Are Isolated From Outputs
  • Accommodates Standard Mode and Fast Mode I2C Devices
  • Applications Include Hot Board Insertion and Bus Extension
  • Low ICC Chip Disable of <1 μA
  • READY Open-Drain Output
  • Supports Clock Stretching, Arbitration, and Synchronization
  • Powered-Off High-Impedance I2C Pins
  • Open-Drain I2C Pins
  • Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
  • ESD Protection Exceeds JESD 22
    • 8000-V Human-Body Model (A114-A)
    • 200-V Machine Model (A115-A)
    • 1000-V Charged-Device Model (C101)

All trademarks are the property of their respective owners.

The TCA4311 is a hot swappable I2C bus buffer that supports I/O card insertion into a live backplane without corruption of the data and clock busses. Control circuitry prevents the backplane from being connected to the card until a stop command or bus idle 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 precharged to 1 V to minimize the current required to charge the parasitic capacitance of the chip.

When the I2C bus is idle, the TCA4311 can be put into shutdown mode by setting the EN pin low. When EN is high, the TCA4311 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.

Both the backplane and card may be powered with supply voltages ranging from 2.7 V to 5.5 V, with no restrictions on which supply voltage is higher.

The TCA4311 has standard open-drain I/Os. The size of the pullup resistors to the I/Os depends on the system, but each side of this buffer must have a pullup resistor. The device is designed to work with Standard Mode and Fast Mode I2C devices in addition to SMBus devices. Standard Mode I2C devices only specify 3 mA in a generic I2C system where Standard Mode devices and multiple masters are possible. Under certain conditions, high termination currents can be used.

The TCA4311 is a hot swappable I2C bus buffer that supports I/O card insertion into a live backplane without corruption of the data and clock busses. Control circuitry prevents the backplane from being connected to the card until a stop command or bus idle 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 precharged to 1 V to minimize the current required to charge the parasitic capacitance of the chip.

When the I2C bus is idle, the TCA4311 can be put into shutdown mode by setting the EN pin low. When EN is high, the TCA4311 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.

Both the backplane and card may be powered with supply voltages ranging from 2.7 V to 5.5 V, with no restrictions on which supply voltage is higher.

The TCA4311 has standard open-drain I/Os. The size of the pullup resistors to the I/Os depends on the system, but each side of this buffer must have a pullup resistor. The device is designed to work with Standard Mode and Fast Mode I2C devices in addition to SMBus devices. Standard Mode I2C devices only specify 3 mA in a generic I2C system where Standard Mode devices and multiple masters are possible. Under certain conditions, high termination currents can be used.

Download View video with transcript Video

Technical documentation

star =Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 1
Type Title Date
* Data sheet TCA4311 Hot Swappable 2-Wire Bus Buffers datasheet (Rev. A) 12 Jun 2014

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Simulation model

HSPICE Model for TCA4311

SCPJ002.ZIP (237 KB) - HSpice Model
Simulation model

TCA4311 IBIS Model

SCPM012.ZIP (44 KB) - IBIS Model
Simulation tool

PSPICE-FOR-TI — PSpice® for TI design and simulation tool

PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
Simulation tool

TINA-TI — SPICE-based analog simulation program

TINA-TI provides all the conventional DC, transient and frequency domain analysis of SPICE and much more. TINA has extensive post-processing capability that allows you to format results the way you want them. Virtual instruments allow you to select input waveforms and probe circuit nodes voltages (...)
User guide: PDF
Package Pins CAD symbols, footprints & 3D models
SOIC (D) 8 Ultra Librarian
VSSOP (DGK) 8 Ultra Librarian

Ordering & quality

Information included:
  • RoHS
  • REACH
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring
Information included:
  • Fab location
  • Assembly location

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​

Videos