SN74ALVCHR16269LR

Overview

The SN74ALVCHR16269LR is a registered bus exchanger from the Texas Instruments Widebus family, designed for 1.65-V to 3.6-V VCC operation. It facilitates multiplexing two ports onto or demultiplexing from a single port. The device features internal B-port registers that store data on the low-to-high transition of the clock input when clock-enable inputs are low. This allows two sequential 12-bit words to be presented as a 24-bit word on the B port. A single storage register is provided for B-to-A data transfer, with a select line choosing between 1B and 2B data for the A outputs.

Feature Summary

• Registered control terminals ensure all transactions are synchronous with the clock signal.
• Active bus-hold circuitry maintains unused or undriven inputs at valid logic states without external resistors.
• Outputs include equivalent series resistors to reduce overshoot and undershoot, eliminating the need for external components.

Applications

• Interface between synchronous DRAMs and high-speed microprocessors
• Multiplexing two ports onto a single port
• Demultiplexing from a single port to two ports

Procurement Notes

Verify the specific package variant (DGG, DGV, or DL) matches the design requirements, as the LR suffix indicates a tape-and-reel packaging option. Confirm the operating temperature range aligns with system specifications. Ensure proper handling of ESD-sensitive components during assembly. Check for any RoHS compliance status updates in the latest datasheet revision.

Selection Notes

Select this component when a registered bus exchanger is required for 12-bit to 24-bit data path conversion. Consider the 1.65-V to 3.6-V supply voltage range for compatibility with various logic families. Evaluate the maximum propagation delay and output drive current against system timing and load requirements. Ensure the 56-pin package fits within the available PCB space constraints.

Part Context

This device belongs to the Texas Instruments ALVCH logic series, which offers wide voltage operation and high-speed performance. The Widebus family provides solutions for complex bus architectures requiring precise data routing and synchronization. The registered nature of the control inputs distinguishes it from combinational bus switches, making it suitable for synchronous systems.

Replacement Considerations

Check for direct pin-compatible alternatives within the same Widebus family. Verify that any substitute supports the same 1.65-V to 3.6-V operating range and has comparable propagation delays. Ensure the replacement device also features registered control inputs if synchronous operation is critical.