SN74ACT573NSR

Overview

The SN74ACT573NSR is an octal D-type transparent latch with 3-state outputs manufactured by Texas Instruments. It operates within a supply voltage range of 4.5V to 5.5V and features TTL-voltage compatible inputs. The device provides a maximum propagation delay of 9.5ns at 5V. It utilizes a 20-pin SOP package and supports an operating temperature range from -40°C to +85°C.

Feature Summary

• Transparent latch operation allows Q outputs to follow D inputs when the latch-enable signal is high, capturing data upon transition to low.
• Buffered output-enable input controls three-state logic levels, isolating bus lines without requiring external interface or pullup components.
• High drive capability enables direct connection to highly capacitive or low-impedance loads suitable for bus-organized systems.

Applications

• Parallel data storage
• Digital bus buffer
• I/O ports implementation

Procurement Notes

Verify the specific NS (SOP) package designation against current TI documentation, as ordering suffixes define physical form factors. Confirm RoHS compliance status and lead finish details via the official Package Option Addendum. Ensure the selected variant matches the required thermal performance and moisture sensitivity level for the intended assembly process.

Selection Notes

Select this component for designs requiring eight-bit latching with tri-state bus isolation in standard 5V logic environments. Verify that the 4.5V to 5.5V supply range aligns with system power rails. Consider the SOP package dimensions and thermal resistance values if board space or heat dissipation constraints exist within the application layout.

Part Context

This part belongs to the SNx4ACT573 family of octal transparent latches. The catalog version SN74ACT573 offers commercial temperature ratings, while military variants like SN54ACT573 provide extended ranges. Other packages include SSOP, SOIC, TSSOP, VQFN, and ceramic options depending on specific mechanical requirements.

Replacement Considerations

SN74ACT573DWR (SOIC package)

FAQ

How does the output-enable pin affect internal latch operations?

The OE pin places outputs in a high-impedance state but does not affect internal latch operations. Data can be retained or entered while outputs are disabled.

What is the recommended method to handle unused inputs?

Unused inputs must never float. They should be connected to a high or low bias, typically GND or VCC, to prevent undefined operational states.