LTC4308CDD#TRPBF

Signal Buffers, Repeaters, Splitters Overview

The LTC4308CDD#TRPBF is a low voltage, level shifting hot swappable 2-wire bus buffer with stuck bus recovery. It allows I/O card insertion into a live backplane without data corruption by isolating backplane and card capacitances. The device supports bidirectional buffering with negative offset from output to input, enabling communication between high VOL output devices and low voltage input side devices where supplies can be as low as 0.9V. If SDAOUT or SCLOUT remain low for 30ms, the IC automatically breaks the connection and generates up to 16 clock pulses to free the bus. During insertion, SDAOUT and SCLOUT are precharged to 1V. The ENABLE input controls connection after stop bits or idle conditions. The READY pin indicates when sides are connected. Operating temperature range is 0°C to 70°C. Supply voltage (VCC) ranges from 2.3V to 5.5V. Supply current is typically 71µA at VCC=5.5V. Shutdown supply current is typically 900µA. Precharge voltage is typically 1V. Logic input threshold voltage is 0.45V to 0.75V. Maximum sink current is 50mA. Package is 8-lead DFN.

Signal Buffers, Repeaters, Splitters Feature Summary

• Bidirectional buffering isolates input and output bus capacitances during live board insertion and removal.
• Automatic stuck bus recovery detects low bus conditions for 30ms and attempts to clear them by generating clock pulses.
• Level shifting capability accommodates systems with supply voltages as low as 0.9V on the input side.
• Output lines are precharged to 1V during insertion to minimize bus disturbances.

Signal Buffers, Repeaters, Splitters Applications

• Live board insertion into servers
• RAID systems
• ATCA architectures

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the component matches the Analog Devices part number LTC4308CDD#TRPBF. Confirm the package type is an 8-lead DFN. Ensure the temperature grade corresponds to the C suffix, indicating operation from 0°C to 70°C. Check that the datasheet aligns with the official Analog Devices documentation for electrical characteristics and pin configurations.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component for applications requiring hot swapping of 2-wire buses with mixed voltage levels. It is suitable for systems needing isolation between backplane and card capacitances. Consider the 0°C to 70°C operating range. Verify compatibility with I2C Fast Mode and SMBus protocols. Ensure the system pull-up resistors meet the rise time accelerator requirements.

Signal Buffers, Repeaters, Splitters Part Context

This part belongs to the LTC4308 series of hot swappable bus buffers. It is functionally similar to the LTC4301L but includes additional features like automatic stuck bus recovery and rise time accelerators. The CDD suffix denotes the 8-lead DFN package with a commercial temperature range. The #TRPBF suffix indicates tape and reel packaging with lead-free finish.

Signal Buffers, Repeaters, Splitters Replacement Considerations

The LTC4301L is a related part but lacks stuck bus recovery and rise time accelerators. When replacing an LTC4301L with the LTC4308, invert the CS signal as the LTC4308 uses an active-high ENABLE pin. Verify that the lower minimum supply voltage of the LTC4308 (2.3V vs 2.7V) is compatible with the system design.