LTC4301IDD Supply Independent Hot Swappable 2-Wire Bus Buffer, 8-Lead DFN 3x3, Industrial

The LTC4301IDD is the industrial temperature version of the supply independent hot swappable 2-wire bus buffer, packaged in an 8-lead 3 mm x 3 mm DFN. It is specified from -40 C to 85 C, so it holds its timing and isolation behaviour in cabinets, roadside enclosures and unheated telecom huts.

The buffer is supply independent: SDA and SCL may be pulled up above or below VCC, which removes the level shifter that mixed 2.5 V, 3.3 V and 5 V cards would otherwise need. Both lines buffer bidirectionally and the local card capacitance stays isolated from the backplane.

A 1 V precharge on both lines defines the connector voltage before contact, and the CS pin gates the input to output path so the host can sequence a live insertion. SDA and SCL present high impedance when VCC is 0 V, keeping an unpowered card from loading the bus.

Clock stretching, arbitration and multi master synchronization are passed through, and the part meets I2C, Fast Mode and SMBus timing to 400 kHz. All pins are rated to 10 kV human body model ESD, which matters on boards that are handled during field service.

Parts are new stock with full traceability, RoHS compliant and lead free; samples and volume pricing are available on request.

• Supply independent operation, pull-ups may be above or below VCC
• Bidirectional buffer for SDA and SCL lines
• Increases bus fanout and isolates line capacitance
• Prevents SDA and SCL corruption during live insertion and removal
• Isolates input SDA and SCL lines from the output
• 10 kV human body model ESD protection on all pins
• 1 V precharge on all SDA and SCL lines
• Supports clock stretching, arbitration and synchronization
• High impedance SDA and SCL pins when VCC = 0 V
• CS pin gates the connection from input to output
• Compatible with I2C, I2C Fast Mode and SMBus up to 400 kHz
• Industrial temperature grade, -40 C to 85 C
• 8-lead 3 mm x 3 mm DFN package with exposed pad

• Live board insertion and removal in rack systems
• Hot swap line cards and backplane I2C buses
• Servers, telecom and networking equipment
• Bus capacitance isolation and fanout expansion
• Redundant or isolated system management buses
• Industrial control, test and instrumentation boards
• Outdoor and industrial enclosures with wide temperature swings

The LTC4301IDD is the choice where a live inserted card must stay isolated from the backplane across the full industrial temperature range.

• 15+ years of electronic components experience
• Secure ordering process
• Excellent customer feedback
• Confirmed delivery dates
• Competitive pricing on volume orders
• Global export experience with responsive after-sales support

We also carry the related parts shown below, so mixed bills of material can ship together from a single supplier.