DM74ALS253N

Overview

The DM74ALS253N is a 3-STATE Dual 1-of-4 Line Data Selector/Multiplexer manufactured by onsemi. It operates within a supply voltage range of 4.5V to 5.5V and supports a free air operating temperature from 0°C to +70°C. The device features two independent multiplexer circuits with common address inputs A and B, separate data inputs (C0-C3), and individual output control inputs. Propagation delays for select-to-output transitions range from 5ns to 21ns, while data-to-output delays vary between 2ns and 14ns depending on the transition direction. Output enable times are specified at 3ns to 14ns, and disable times range from 2ns to 14ns.

Feature Summary

• Contains full on-chip decoding to select one-of-four data sources based on a unique two-bit binary code at the Select Inputs.
• Output control circuitry incorporates a power-up 3-STATE feature to prevent bus access conflicts during initialization.
• Select input buffers incorporate internal overlap features to ensure that select input changes do not cause invalid output transients.

Applications

• Data routing in digital systems requiring dual channel selection
• Bus interface applications utilizing 3-STATE outputs
• Logic design compatible with LS family counterparts

Procurement Notes

Verify component authenticity through authorized distribution channels due to discontinued status. Confirm package integrity matches the N16E specification for 16-Lead Plastic Dual-In-Line Package. Review datasheet electrical characteristics against system requirements, specifically propagation delay limits under varying load conditions. Ensure environmental compliance documentation aligns with project specifications.

Selection Notes

Select this component when pin and functional compatibility with LS family counterparts is required alongside improved switching performance. Consider the ALS series advantages for applications needing faster propagation delays compared to standard TTL. Verify that the 3-STATE output capability meets bus isolation requirements. Evaluate thermal dissipation needs given the specific junction-to-ambient thermal resistance values for the PDIP package.

Part Context

This part belongs to the 74ALS logic family, characterized by advanced oxide-isolated, ion-implanted Schottky technology. It serves as a high-speed alternative to standard logic families, offering enhanced switching performance guaranteed over the full temperature and supply voltage range. The device integrates non-inverting 3-STATE output buffers for efficient signal management.

Replacement Considerations

Consult official manufacturer documentation for verified substitute part numbers. Cross-reference functional equivalents ensuring identical pinout and electrical specifications. Validate that any replacement maintains compatibility with existing system constraints regarding voltage levels and signal timing.

FAQ

How does the device handle select input changes?

The select input buffers incorporate internal overlap features to ensure that select input changes do not cause invalid output transients.

What is the function of the Output Control inputs?

When at the high level, the Output Control inputs place the corresponding output in the high impedance OFF-State.