SN74AHCT573NSR

Overview

The SN74AHCT573NSR is an octal transparent D-type latch with three-state outputs manufactured by Texas Instruments. It operates within a supply voltage range of 4.5 V to 5.5 V and supports an operating temperature range from -40°C to +85°C. The device features TTL-voltage compatible inputs, ensuring seamless integration with standard logic families. Key electrical characteristics include a high-level output current of -8 mA and a low-level output current of 8 mA at 4.5 V. Propagation delays are specified as 6.5 ns maximum for D-to-Q transitions and 7.5 ns maximum for LE-to-Q transitions under typical load conditions.

Feature Summary

• TTL-voltage compatible inputs allow direct interfacing with standard TTL logic systems without requiring level shifting components.
• Three-state outputs provide controlled bus driving capabilities through a buffered output-enable input, minimizing bus loading when disabled.
• Transparent latch operation enables Q outputs to follow D inputs while the latch-enable signal is active, facilitating real-time data capture.

Applications

• Register files in digital processing systems
• Bus-oriented memory architectures
• Parallel-to-serial data conversion circuits

Procurement Notes

Verify that the component matches the specific NS package variant and tape-and-reel configuration. Confirm the manufacturer designation is Texas Instruments and check for RoHS compliance status. Ensure the ordering suffix corresponds to the required packaging format before finalizing procurement orders.

Selection Notes

Select this component when TTL-compatible input thresholds are required alongside CMOS performance levels. The AHCT series bridges the gap between older TTL standards and modern CMOS technologies. Consider the three-state output capability if bus isolation or multi-driver configurations are necessary for the target application design.

Part Context

This part belongs to the SN74AHCT573 family of octal transparent D-type latches. It shares functional similarities with other members like the SN74HCT573 but offers enhanced speed and lower power consumption characteristic of the AHC technology. The NS suffix indicates a plastic small-outline package designed for surface-mount assembly.

Replacement Considerations

SN74AHCT573DWR

FAQ

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

The output-enable input places the outputs in a high-impedance state but does not affect the internal operations of the latches. Data can be retained or entered while the outputs are disabled.

What is the purpose of tying OE to VCC during power-up?

Tying the output-enable input to VCC through a pullup resistor ensures the high-impedance state during power-up or power-down, preventing unintended bus driving.