LTC4304IDD#PBF

Signal Buffers, Repeaters, Splitters Overview

The LTC4304IDD#PBF is a hot swappable 2-wire bus buffer designed for I/O card insertion into live backplanes without data corruption. It provides bidirectional buffering for SDA and SCL lines, isolating backplane and card capacitances. The device features automatic stuck bus recovery by generating up to 16 clock pulses if the bus remains low for ≥30ms. It supports I²C, Fast-Mode, and SMBus standards with operation up to 400kHz. Operating voltage ranges from 2.7V to 5.5V, with an industrial temperature range of -40°C to +85°C. It includes rise-time accelerators, a 1V precharge function, and ±15kV HBM ESD protection in a 10-lead DFN package.

Signal Buffers, Repeaters, Splitters Feature Summary

• Automatic disconnection and recovery mechanism for stuck buses using internal clocking
• Bidirectional buffering that isolates input and output capacitances during live insertion
• Rise-time accelerators allow use of larger pull-up resistors to reduce power consumption
• Supply independent operation allowing bus pull-up voltages above or below VCC

Signal Buffers, Repeaters, Splitters Applications

• Hot board insertion in CompactPCI systems
• Servers requiring live backplane connectivity
• RAID systems needing bus isolation
• Capacitance buffering and bus extension applications

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the specific ordering suffix #PBF indicates lead-free packaging compliance. Confirm the IDD suffix corresponds to the industrial temperature grade (-40°C to +85°C) rather than the commercial grade. Ensure the DFN package type matches the design footprint requirements. Cross-reference the manufacturer's current datasheet revision for any updates to electrical characteristics or pin definitions before finalizing procurement specifications.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when designing systems that require hot swapping of I/O cards into active backplanes. It is suitable for applications needing to isolate bus capacitance between the backplane and the peripheral card. Choose this part if the system requires automatic recovery from stuck bus conditions without external microcontroller intervention. Ensure the operating voltage range of 2.7V to 5.5V aligns with the system supply rails.

Signal Buffers, Repeaters, Splitters Part Context

The LTC4304 belongs to Analog Devices' family of hot swappable 2-wire bus buffers. It complements parts like the LTC4300 and LTC4301 by adding automatic stuck bus recovery capabilities. Unlike addressable buffers such as the LTC4302, it functions as a transparent bidirectional buffer. It is distinct from the LTC4305, which offers multiplexing functionality for multiple bus channels.

Signal Buffers, Repeaters, Splitters Replacement Considerations

LTC4304CDD#PBF (Commercial Temperature Grade)

Signal Buffers, Repeaters, Splitters FAQ

How does the LTC4304 handle a stuck bus condition?

If SDAOUT or SCLOUT is low for 30ms or more, the device breaks the connection, pulls FAULT low, and automatically generates up to 16 clock pulses on SCLOUT to attempt to free the bus.

What is the purpose of the ACC pin?

The ACC pin controls the rise-time accelerators. Connecting it to GND enables all four accelerators, connecting it to VCC disables them, and floating it enables only the output-side accelerators.

Can the LTC4304 operate with different voltage levels on the input and output sides?

Yes, it supports supply-independent operation, allowing bus pull-up voltages to be higher or lower than the VCC supply voltage.