Texas Instruments CD74HC154EN

Overview

CD74HC154EN 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 as low as 30 ns at 6V with 50 pF load.

For engineers reviewing the CD74HC154EN datasheet, CD74HC154EN pinout, CD74HC154EN application, or CD74HC154EN equivalent, this device serves in address decoding for memory expansion, I/O port selection in microcontroller systems, and logic-level signal routing where low-power, wide-voltage operation and precise 1-of-16 output activation are required.

Technical Context

The CD74HC154EN implements combinational logic decoding using four binary address inputs (A0–A3) to assert exactly one of sixteen active-low outputs (Y0–Y15) when both enables are low. Its dual enable architecture supports cascading multiple units and demultiplexing by treating one enable as data input while holding the other low.

It uses standard HC-series CMOS technology with balanced propagation delays (tPLH ≈ tPHL), rail-to-rail output swing, and input thresholds referenced to VCC (VIH = 1.5V min at 2V, 4.2V min at 6V; VIL = 0.5V max at 2V, 1.8V max at 6V), ensuring noise immunity and compatibility across supply voltages.

Key Specifications

Pinout & Package

CD74HC154EN is housed in a 24-lead plastic dual in-line package (PDIP), 0.300-inch body width (JEDEC MS-001), with pin 1 located at the top-left corner marked by a notch or dot. Thermal resistance θJA is 67°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC154N and MC74HC154ANG, the CD74HC154EN delivers guaranteed operation over the full military temperature range and the lowest specified propagation delay in its family, making it optimal for high-reliability, timing-critical, or thermally demanding implementations.

Availability

CD74HC154EN is available at Aetrix Electronics and suitable for memory address decoding, microcontroller I/O expansion, industrial control logic, and test equipment signal routing requiring stable component supply across extended temperature ranges.

Supply support for CD74HC154EN 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 company specializing in analog, embedded processing, and logic solutions, with leadership in high-reliability and industrial-grade components.

The CD74HC154EN belongs to TI's CD74HC high-speed CMOS logic family, designed for robust, low-power, wide-temperature digital interfacing in mission-critical and legacy-system upgrade applications.

FAQ

What is the maximum clock/data toggle rate supported by CD74HC154EN?

The CD74HC154EN is a combinational logic device without an internal clock; its effective toggle rate depends on propagation delay and load. With a max tPD of 30 ns at 6V and 50 pF, the CD74HC154EN supports reliable address transitions up to approximately 15 MHz in well-designed systems with controlled trace impedance and proper decoupling.

Can CD74HC154EN operate reliably at 3.3V supply voltage?

Yes, CD74HC154EN is fully specified for 2V to 6V operation. At 3.3V, VIH is guaranteed ≥2.1V and VIL ≤1.1V, providing >30% noise margin. Propagation delay is typically 44 ns (max 53 ns) with 50 pF load, making CD74HC154EN compatible with 3.3V microcontrollers and FPGAs without level translation.

Does CD74HC154EN have built-in ESD protection?

CD74HC154EN includes standard CMOS input protection diodes rated for ±20 mA DC input current (IIK), but it is explicitly noted as ESD-sensitive in the datasheet. Users must follow proper IC handling procedures - including grounded workstations, anti-static packaging, and ionized air - as the device lacks enhanced HBM or CDM ESD hardening beyond baseline CMOS structures.

How are the enable inputs E1 and E2 used in demultiplexing mode?

In demultiplexing mode, one enable (e.g., E1) serves as the data input, while the other (E2) is held low. The four address inputs (A0–A3) select which of Y0–Y15 reflects the state of E1. A high on either E1 or E2 forces all outputs high (inactive), so CD74HC154EN requires both enables low to activate decoding - a safety feature preventing spurious outputs during power-up or reset.

Is CD74HC154EN pin-compatible with CD74HCT154EN?

Yes, CD74HC154EN and CD74HCT154EN share identical 24-pin PDIP mechanical packaging and pinout. However, they differ electrically: CD74HC154EN operates from 2V–6V with CMOS-input thresholds, while CD74HCT154EN is 4.5V–5.5V only and features TTL-compatible inputs (VIH = 2.0V min, VIL = 0.8V max). They are not functionally interchangeable without verifying supply and driver compatibility.