SN74ALS259N

Overview

The SN74ALS259N is an 8-bit addressable latch from the Texas Instruments ALS logic family, housed in a 16-pin PDIP package. It operates on a supply voltage of 4.5 V to 5.5 V with a typical operating temperature range of 0°C to 70°C. The device features asynchronous parallel clear and active-high outputs. Propagation delays vary by input: data-to-output ranges from 4 ns to 22 ns (max), while address-to-output ranges from 4 ns to 26 ns (max). Low-level output current reaches up to 8 mA.

Feature Summary

• Performs serial-to-parallel conversion with storage capabilities for general-purpose digital systems
• Functions as an active-high decoder or demultiplexer with selectable addressing modes
• Includes an asynchronous parallel clear input to force all outputs low simultaneously

Applications

• Working registers in digital systems
• Serial-holding registers
• Active-high decoders or demultiplexers

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official Package Option Addendum to confirm the exact physical package type and material finish. Ensure the selected variant matches the required operating temperature range for your application environment before finalizing procurement.

Selection Notes

Select this component when designing circuits requiring 8-bit addressable latching or decoding functions within standard industrial temperature limits. Verify that the system power supply remains strictly between 4.5 V and 5.5 V to maintain electrical characteristics. Confirm that the propagation delay specifications meet the timing requirements of the target digital interface.

Part Context

This part belongs to the Texas Instruments SN74ALS259 series, which includes military-grade variants like the SN54ALS259J characterized for -55°C to 125°C operation. The N suffix specifically denotes the standard plastic dual in-line package suitable for through-hole mounting.

Replacement Considerations

SN74ALS259DR

FAQ

What are the four distinct functional modes of the SN74ALS259N?

The device supports addressable-latch mode, memory mode, 1-of-8 decoding/demultiplexing mode, and clear mode, determined by the states of the CLR and G inputs.

How does the enable input affect the addressable-latch mode?

In addressable-latch mode, holding the enable input high prevents erroneous data entry while address lines are changing, ensuring stable state transitions.