PCA9646D,118

Signal Buffers, Repeaters, Splitters Overview

The PCA9646D,118 is a buffered 4-channel 2-wire bus switch manufactured by NXP Semiconductors. It provides impedance isolation for I2C-bus, SMBus, and PMBus applications. The device operates with supply voltages from 2.7 V to 5.5 V and supports Standard-mode, Fast-mode, and Fast-mode Plus (Fm+) protocols. Each channel features independent enable control via a programmable register. The IC includes hysteresis on inputs to enhance noise immunity and offers a 30 mA static sink capability. It is designed to expand address space and increase maximum load capacitance for large arrays of components.

Signal Buffers, Repeaters, Splitters Feature Summary

• Provides four independently enabled channels with impedance isolation between outputs
• Supports bidirectional data buffering and unidirectional clock signal buffering
• Includes input hysteresis to improve noise immunity on high-capacitance buses
• Features active LOW reset functionality to clear the control register and disable buffers

Signal Buffers, Repeaters, Splitters Applications

• Large arrays of I2C-bus components such as LED displays
• Power management systems requiring bus expansion
• Game consoles, computers, and RAID systems

Signal Buffers, Repeaters, Splitters Procurement Notes

Verify the specific ordering suffix '118' against the manufacturer's current documentation to confirm the packing method and availability status. Ensure the component meets RoHS compliance requirements for your target market. Cross-reference the part number with official distributor catalogs to validate authenticity and check for any recent product change notifications or end-of-life notices.

Signal Buffers, Repeaters, Splitters Selection Notes

Select this component when designing systems that require significant fan-out or long-distance bus driving capabilities. It is suitable for interfacing buses with different operating frequencies by isolating slower slave devices. Consider its compatibility with existing P82B715 line drivers if extending cable lengths beyond standard capacitance limits. Ensure the system design accommodates the open-drain nature of the output ports requiring external pull-up resistors.

Signal Buffers, Repeaters, Splitters Part Context

This component belongs to the PCA9646 family of buffered 2-wire bus switches. It serves as an alternative to multiplexers like the PCA9546A, offering drop-in pin compatibility while providing superior load isolation. Unlike simple switches, it acts as a buffer, allowing each branch to support the maximum specified load capacitance independently without affecting other channels.

Signal Buffers, Repeaters, Splitters Replacement Considerations

The PCA9546A is documented as a drop-in compatible alternative. Verify electrical characteristics and control register configurations before substitution.