Texas Instruments CD74HCT354E

Overview

CD74HCT354E from Texas Instruments is an 8-line to 1-line data selector/multiplexer with transparent latches, three-state complementary outputs, and LSTTL-compatible inputs. It operates at 4.5V–5.5V, delivers 20ns typical propagation delay (Dn→Y, CL=15pF), supports -55°C to +125°C industrial/military temperature range, and enables bus-oriented data routing in high-reliability digital systems.

For engineers reviewing the CD74HCT354E datasheet, CD74HCT354E pinout, CD74HCT354E application, or CD74HCT354E equivalent, this page provides verified functional identity, validated pin-level circuit roles, confirmed HCT-family logic compatibility, real-world bus-driving capability (15 LSTTL loads), and precise timing behavior under defined load and temperature conditions.

Technical Context

The CD74HCT354E integrates eight independent data latches controlled by S0–S2 address inputs and a latch-enable (LE) signal, with data enable (E) governing transparency versus latching behavior. Its output-enable architecture uses three independent OE pins (OE1, OE2, OE3) to drive complementary Y/Y̅ outputs into high-impedance states.

It implements CMOS logic with TTL-compatible input thresholds (VIH ≥ 2V, VIL ≤ 0.8V at VCC = 5V), achieves balanced rise/fall times (12ns typ. @ CL = 50pF), and maintains stable operation across full military-grade temperature range without derating-enabling use in avionics, test equipment, and ruggedized control systems.

Key Specifications

Pinout & Package

CD74HCT354E is housed in a 20-pin plastic dual in-line package (PDIP), with 0.3-inch body width and standard through-hole mounting footprint. Pin spacing follows JEDEC MS-001, compatible with legacy PCB layouts and manual soldering processes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-to-1 multiplexer/register applications.

Compared with SN74HCT251N, CD74HCT354E adds transparent latching and triple OE control for robust bus arbitration; compared with CD74HC354E, it trades supply flexibility for guaranteed LSTTL interoperability-making CD74HCT354E optimal for legacy 5V TTL system upgrades.

Availability

CD74HCT354E is available at Aetrix Electronics and suitable for industrial automation, aerospace data acquisition, automated test equipment, and military communications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HCT354E 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 electronic components.

CD74HCT354E belongs to TI's High-Speed CMOS Logic (HCT) family, designed specifically for seamless 5V TTL system upgrades-delivering CMOS power efficiency while preserving legacy input/output compatibility and timing behavior.

FAQ

What is the primary function of the CD74HCT354E?

The CD74HCT354E is an 8-line to 1-line data selector/multiplexer with integrated transparent latches and three-state complementary outputs. It routes one of eight input data lines (D0–D7) to dual outputs (Y/Y̅) based on a 3-bit address (S0–S2), with latch-enable (LE) and data-enable (E) controls. Its design enables both real-time selection and registered data storage, making CD74HCT354E ideal for bus-oriented digital systems requiring deterministic timing and high noise immunity.

Does the CD74HCT354E support direct interface with 74LS-series logic?

Yes, the CD74HCT354E features LSTTL-compatible input thresholds: VIH ≥ 2.0V (minimum) and VIL ≤ 0.8V (maximum) at VCC = 5V. This ensures reliable recognition of 74LS output levels without external level-shifting circuitry. The CD74HCT354E also drives 15 LSTTL loads, allowing direct fanout to legacy TTL devices-confirming its role as a drop-in upgrade for 74LS354-based designs where CMOS power savings and extended temperature range are needed.

What are the key timing parameters for the CD74HCT354E at 5V operation?

At VCC = 5V and CL = 15pF, the CD74HCT354E exhibits 20ns typical propagation delay from data input (Dn) to output (Y), 23ns from enable (E) to output, and 25ns from select input (Sn) or latch-enable (LE) to output. Output enable/disable times are 14ns (tPZL/tPLZ) and 13ns (tPZH/tPHZ) respectively. These values-verified across -55°C to +125°C-ensure predictable performance in time-critical applications such as ATE signal routing and avionics data switching where CD74HCT354E is deployed.

How does the three-state output architecture of the CD74HCT354E work?

The CD74HCT354E uses three independent active-low output-enable inputs (OE1, OE2, OE3) to control its complementary Y/Y̅ outputs. All three OE pins must be low for outputs to drive; if any OE is high, both Y and Y̅ enter high-impedance (Z) state. This architecture enables fine-grained bus arbitration-e.g., OE1 may control local subsystem access while OE2/OE3 coordinate with master controllers. Unlike simpler multiplexers, CD74HCT354E's triple-OE design prevents bus contention in complex hierarchical systems without external logic.

Is the CD74HCT354E suitable for extended temperature applications?

Yes, the CD74HCT354E is fully specified from -55°C to +125°C, with all electrical parameters-including propagation delay, output drive, and input thresholds-guaranteed across this range. Its PDIP package and HCT process technology ensure stable operation in automotive engine compartments, aerospace avionics bays, and industrial motor control enclosures. This makes CD74HCT354E a qualified solution for applications where commercial-grade parts (0°C to +70°C) would fail due to thermal stress or parameter drift.