LTC4315CMS#PBF

Signal Buffers, Repeaters, Splitters Overview

The LTC4315CMS#PBF is a hot-swappable 2-wire bus buffer manufactured by Analog Devices Inc. It provides bidirectional buffering for I2C and SMBus signals while maintaining a low offset voltage and high noise margin up to 0.3 times VCC. The device supports level translation between 1.5V, 1.8V, 2.5V, 3.3V, and 5V busses. Key electrical parameters include an input supply voltage range of 2.9V to 5.5V, a typical input supply current of 8.1mA when enabled, and a maximum operating frequency of 400kHz. It features selectable rise time accelerator currents and operates within an ambient temperature range of 0°C to 70°C in a 12-lead MSOP package.

Signal Buffers, Repeaters, Splitters Feature Summary

• Provides capacitance buffering and isolation between upstream and downstream bus segments to prevent corruption during live board insertion.
• Features a high noise margin compatible with non-compliant I2C devices that drive a high VOL, allowing series connection of multiple buffers.
• Includes automatic stuck bus disconnect and recovery logic that generates clock pulses to free a stuck bus condition.
• Offers selectable rise time accelerator strength via the ACC pin to optimize signal integrity and power consumption.

Signal Buffers, Repeaters, Splitters Applications

• Bidirectional buffering to increase fanout on I2C and SMBus networks
• Live board insertion and removal protection in telecommunications systems such as ATCA
• Level translation between different bus voltage domains (1.5V, 1.8V, 2.5V, 3.3V, and 5V)
• Capacitance buffering and bus extension in server and PMBus applications

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the specific ordering suffix to confirm the package type and temperature grade. The CMS suffix indicates a 12-lead plastic MSOP package with an operating temperature range of 0°C to 70°C. Ensure compatibility with the target system's voltage levels and interface requirements before procurement.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when high noise margin and hot-swap capability are required for I2C or SMBus interfaces. Consider the rise time accelerator settings based on bus capacitance and pull-up resistor values. Verify that the supply voltages match the required level translation needs and that the package size fits the design constraints.

Signal Buffers, Repeaters, Splitters Part Context

This part belongs to the LTC4315 family of 2-wire bus buffers. It is designed to address challenges in complex digital systems where bus capacitance and live insertion events can disrupt communication. The MSOP variant offers a compact solution for space-constrained designs requiring robust I2C/SMBus connectivity.

Signal Buffers, Repeaters, Splitters Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Consult manufacturer resources for potential alternatives if this specific package or temperature grade is unavailable.

Signal Buffers, Repeaters, Splitters FAQ

How does the LTC4315 handle live board insertion?

During insertion, the SDA and SCL lines are precharged to approximately 1V to minimize bus disturbances. Connection is established only after ENABLE is asserted and a stop bit or bus idle condition is detected.

What is the function of the ACC pin?

The ACC pin controls the strength of the rise time accelerators. Grounding it enables strong acceleration, leaving it open provides a 2.5mA pull-up current, and driving it high disables the accelerators.

How does the device recover from a stuck bus condition?

If both data and clock remain low for 45ms, the FAULT signal is generated. If DISCEN is high, the input is disconnected, and up to sixteen clock pulses are generated on SCLOUT to attempt to free the stuck bus.