Texas Instruments CD74HC154ENG4

Overview

CD74HC154ENG4 from Texas Instruments is a high-speed CMOS 4-to-16-line decoder/demultiplexer with dual enable inputs (E1, E2), operating from 2V to 6V, featuring 24-pin PDIP packaging, -55°C to +125°C temperature range, and propagation delay of 30 ns (typ.) at 6V with 50 pF load. It performs address decoding in memory expansion and I/O selection in industrial control systems.

For engineers reviewing the CD74HC154ENG4 datasheet, CD74HC154ENG4 pinout, CD74HC154ENG4 application, or CD74HC154ENG4 equivalent, this page delivers verified functional role, validated timing specs, confirmed package mapping, real-world use cases, and two technically documented alternative parts for design-in evaluation.

Technical Context

The CD74HC154ENG4 implements active-low 4-bit binary decoding with two independent enable inputs that force all outputs high when asserted - enabling cascading of multiple devices for 5-to-32 or 6-to-64 decoding. Its logic is fully static CMOS, with balanced tPLH/tPHL propagation delays and matched transition times across all 16 outputs.

It supports demultiplexing by using one enable as data input while holding the other low, routing the signal to one of sixteen outputs selected by A0–A3. Input hysteresis and noise immunity (NIL/NIH = 30% of VCC at 5V) ensure robust operation in electrically noisy environments.

Key Specifications

Pinout & Package

CD74HC154ENG4 uses a 24-pin plastic dual in-line package (PDIP), 0.300-inch body width, with standard through-hole mounting and JEDEC MS-001AC outline. Pin 1 is located at top-left corner with notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-to-16 decoder/demultiplexer applications.

Compared with SN74HC154N, CD74HC154ENG4 provides guaranteed operation at -55°C and +125°C - essential for mission-critical hardware - while CD74HCT154EN trades voltage flexibility (4.5–5.5V only) for native TTL input compatibility, simplifying integration with older digital subsystems.

Availability

CD74HC154ENG4 is available at Aetrix Electronics and suitable for memory expansion, I/O port extension, industrial control logic, and automated test equipment requiring stable component supply across extreme temperature conditions.

Supply support for CD74HC154ENG4 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 IC design.

The CD74HC154ENG4 belongs to TI's High-Speed CMOS Logic family, engineered for low-power, wide-temperature digital interfacing in aerospace, defense, and industrial automation systems where deterministic timing and ruggedness are mandatory.

FAQ

What is the maximum clock/data frequency supported by CD74HC154ENG4?

The CD74HC154ENG4 is a combinational logic device with no internal clock; its usable frequency depends on propagation delay and system timing margins. With 30 ns max tPLH/tPHL at 6V and 50 pF load, it supports reliable address decoding up to approximately 33 MHz in synchronous designs. For demultiplexing, data rate is limited by enable-to-output delay (also 30 ns max), making CD74HC154ENG4 suitable for burst-mode control signals below 25 MHz.

Can CD74HC154ENG4 operate at 3.3V supply voltage?

Yes, CD74HC154ENG4 is fully specified for 2V to 6V operation, including 3.3V. At VCC = 3.3V, VIH = 2.31V (min), VIL = 0.99V (max), VOH ≥ 3.2V (with 20 µA sink), and VOL ≤ 0.1V - ensuring clean interfacing with 3.3V microcontrollers and FPGAs without level translation. Propagation delay increases to ~55 ns (max) at 3.3V/50 pF.

How does the dual-enable feature of CD74HC154ENG4 improve system design?

The dual-enable (E1 and E2) architecture of CD74HC154ENG4 allows hierarchical control: one enable can serve as global chip select while the other acts as function mode select or data strobe. This eliminates external AND gates needed for multi-level decoding, reduces PCB layer count, and enables cascading - for example, using E1 of a second CD74HC154ENG4 as Y0 output from the first to build a 5-to-32 decoder. Both enables are active-low and ORed internally.

Is CD74HC154ENG4 pin-compatible with CD74HCT154EN?

Yes, CD74HC154ENG4 and CD74HCT154EN share identical 24-pin PDIP mechanical footprint and pin assignment (including VCC, GND, A0–A3, E1, E2, Y0–Y15). However, they differ electrically: CD74HC154ENG4 accepts CMOS-level inputs (VIH = 70% VCC), while CD74HCT154EN requires TTL-compatible thresholds (VIH = 2V min at 5V). Swapping them requires verifying upstream driver compatibility.

What thermal considerations apply to CD74HC154ENG4 in high-density layouts?

CD74HC154ENG4 in PDIP package has θJA = 67°C/W (typ.). At 5V and 16 outputs driving 10 mA each, total power dissipation is ~12 mW (quiescent) + ~40 mW (dynamic), resulting in ~3.5°C junction rise above ambient. No heatsinking is required, but maintain ≥0.5 mm clearance from adjacent heat sources and use 2+ thermal vias under GND pin 12 to enhance conduction in multilayer boards.