PCA9512AD,118

Signal Buffers, Repeaters, Splitters Overview

The PCA9512AD,118 is a hot swappable I2C-bus and SMBus buffer manufactured by NXP Semiconductors. It provides bidirectional buffering for SDA and SCL lines to increase fan-out and prevent bus corruption during live board insertion or removal from multipoint backplane systems. The device includes two dedicated supply voltage pins (VCC and VCC2) to facilitate level shifting between 3.3 V and 5 V systems while maintaining optimal noise margins. Either pin may be powered with supply voltages ranging from 2.7 V to 5.5 V without constraints on which supply voltage is higher. The component operates within an ambient temperature range of -40 °C to +85 °C.

Signal Buffers, Repeaters, Splitters Feature Summary

• Bidirectional buffering isolates backplane and card capacitances to prevent data and clock bus corruption during hot swapping.
• Built-in rise time accelerators allow the use of weaker DC pull-up currents while meeting signal rise time requirements.
• Control circuitry prevents connection until a stop bit or bus idle occurs, avoiding bus contention.

Signal Buffers, Repeaters, Splitters Applications

• cPCI cards requiring insertion or removal from operating systems
• VME backplane cards requiring hot swap capability
• AdvancedTCA cards requiring hot swap capability

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to confirm package type and packing method. The '118' suffix indicates a reel packaging format. Ensure compatibility with system voltage levels and check for any recent product change notifications regarding availability or specifications before finalizing procurement plans.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when designing multipoint backplane systems that require hot swapping capabilities. It is suitable for applications needing isolation between backplane and card capacitances. Verify that the system supports the required 2.7 V to 5.5 V supply range and that the ACC pin configuration aligns with the desired rise time accelerator settings.

Signal Buffers, Repeaters, Splitters Part Context

The PCA9512A series includes variants such as the PCA9510A, PCA9511A, PCA9513A, and PCA9514A. The PCA9512AD specifically features hardware disable capability for rise time accelerators via the ACC pin and dual supply pins for level translation. It differs from other series members by its specific combination of features including the ACC pin and dual VCC pins.

Signal Buffers, Repeaters, Splitters Replacement Considerations

Direct replacements within the same family include the PCA9512ADP in TSSOP8 packaging. Other series members like PCA9511A or PCA9513A offer similar buffering but lack specific features such as the ACC pin or dual supply pins. Verify pinout and feature compatibility before substitution.

Signal Buffers, Repeaters, Splitters FAQ

How does the PCA9512AD handle hot swapping?

It uses control circuitry to prevent connection until a stop bit or bus idle occurs, isolating capacitances and preventing bus contention during insertion or removal.

What is the function of the ACC pin?

The ACC pin enables or disables the rise time accelerators on all SDA and SCL lines. Driving it to VCC2 enables them, while driving it to GND disables them for lightly loaded systems.

Can the PCA9512AD operate with different supply voltages on VCC and VCC2?

Yes, either pin can be powered with voltages ranging from 2.7 V to 5.5 V, allowing for level shifting between different voltage domains without constraints on which is higher.