Texas Instruments CD74HCT253E

Overview

CD74HCT253E from Texas Instruments is a dual 4-to-1 line selector/multiplexer with three-state outputs, designed for digital signal routing in bus-oriented systems. It features common S0/S1 select inputs, independent 1OE/2OE output-enable controls, operates from 4.5V to 5.5V, supports -55°C to +125°C temperature range, and delivers 38 ns typical propagation delay (data-to-output, VCC = 4.5V, CL = 50 pF).

For engineers reviewing the CD74HCT253E datasheet, CD74HCT253E pinout, CD74HCT253E application, or CD74HCT253E equivalent, key selection criteria include LSTTL-compatible input thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V), high-impedance three-state outputs for bus sharing, fanout of 10 LSTTL loads, and PDIP-16 packaging for through-hole prototyping and industrial control interfaces.

Technical Context

The CD74HCT253E implements two independent 4-input multiplexers sharing select lines S0 and S1, enabling simultaneous routing of two 4-bit data streams. Each section drives a three-state output (1Y or 2Y) controlled by dedicated enable inputs (1OE, 2OE), allowing bidirectional bus arbitration without external logic.

Its HCT logic family ensures direct compatibility with legacy LSTTL voltage levels while maintaining CMOS power efficiency. Input leakage remains ≤ ±1 µA at VCC = 5.5 V, and three-state output leakage is ≤ ±10 µA over full temperature range, supporting reliable operation in noise-sensitive embedded control environments.

Key Specifications

Pinout & Package

CD74HCT253E is housed in a 16-lead plastic dual in-line package (PDIP) with 0.3-inch body width and through-hole mounting. Pin spacing follows JEDEC MS-001 standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 4:1 multiplexer applications.

Compared with CD74HCT253E, SN74HCT153N offers guaranteed pin-to-pin equivalence and identical thermal performance in PDIP-16, whereas 74VHC253N trades LSTTL compatibility for broader voltage operation and lower static power-making it unsuitable for mixed-logic designs without interface redesign.

Availability

CD74HCT253E is available at Aetrix Electronics and suitable for industrial control panels, automotive diagnostic tools, and test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HCT253E includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions with over 90 years of innovation in high-reliability components.

The CD74HCT253E belongs to TI's High-Speed CMOS Logic (HCT) product line, engineered specifically for seamless integration with legacy TTL systems while delivering CMOS power efficiency and noise immunity.

FAQ

What is the maximum clock frequency supported by CD74HCT253E in a data-select application?

The CD74HCT253E does not operate on a clock signal-it is combinatorial logic. Its usable data rate depends on propagation delay and system setup/hold timing. With 38 ns typical propagation delay (data-to-output) and 12 ns typical output transition time at VCC = 4.5 V, CD74HCT253E reliably supports multiplexing rates up to approximately 12 MHz in well-designed PCB layouts with controlled trace impedance and proper decoupling.

Can CD74HCT253E drive a 50 pF load while maintaining specified timing?

Yes. All switching specifications for CD74HCT253E-including propagation delay (tPLH/tPHL), enable/disable times (tPZH/tPLZ), and transition times (tTLH/tTHL)-are explicitly characterized at CL = 50 pF per output, as confirmed in the official Texas Instruments datasheet SCHS170B. The CD74HCT253E meets its rated 38 ns max propagation delay under this exact load condition.

Is CD74HCT253E RoHS compliant and lead-free?

Yes. According to TI's Packaging Information Addendum (Feb 2020), CD74HCT253E carries "Green (RoHS & no Sb/Br)" eco plan designation and "NIPDAU" lead/ball finish, confirming full compliance with EU RoHS Directive 2011/65/EU and absence of lead, bromine, and antimony-based flame retardants. The CD74HCT253E is suitable for lead-free reflow soldering processes.

How does the three-state output behavior work on CD74HCT253E?

Each output (1Y and 2Y) is independently controlled by its dedicated output-enable input (1OE and 2OE). When OE is HIGH, the corresponding Y output enters high-impedance (Hi-Z) state-electrically disconnecting from the bus. When OE is LOW, the selected input (per S0/S1) drives the output. This allows CD74HCT253E to share a common bus line with other devices without contention, provided only one OE is active at a time.

What is the recommended bypass capacitor value for CD74HCT253E?

Texas Instruments recommends a 0.1 µF ceramic capacitor placed as close as possible between VCC (Pin 16) and GND (Pin 7) to suppress high-frequency supply noise and ensure stable switching performance. For systems with heavy dynamic loading or long power traces, adding a bulk 4.7 µF–10 µF tantalum or aluminum electrolytic capacitor nearby further improves low-frequency regulation. This applies directly to CD74HCT253E in PDIP-16 layout.