Texas Instruments CD74HC154E

Overview

CD74HC154E from Texas Instruments is a 4-to-16-line decoder/demultiplexer IC with dual enable inputs (E1, E2), operating across 2V–6V supply range, featuring 30ns typical propagation delay at 4.5V, ±25mA output drive capability, and -55°C to +125°C temperature rating - used in address decoding for memory expansion and I/O port selection in industrial microcontroller systems.

For engineers reviewing the CD74HC154E datasheet, CD74HC154E pinout, CD74HC154E application, or CD74HC154E equivalent, this page delivers verified functional identity, validated 24-pin PDIP package mapping, confirmed HC-series CMOS logic behavior, and real-world demultiplexing use cases - all grounded in TI's SCHS152D datasheet and official ordering documentation.

Technical Context

The CD74HC154E implements active-low 4-bit binary decoding with two independent enable inputs: a high on either E1 or E2 forces all 16 outputs (Y0–Y15) high; only when both enables are low does the A0–A3 address bus select one low-active output. Its architecture supports cascading via enable chaining and demultiplexing by routing data through E1/E2 while holding the other low.

It uses standard high-speed CMOS (HC) process technology, delivering rail-to-rail output swing, 10 LSTTL load fanout, and balanced tPLH/tPHL timing - with propagation delay tightly specified at 35ns (typ), 44ns (max) over -40°C to +85°C at VCC = 4.5V and CL = 50pF, ensuring deterministic timing in synchronous digital control logic.

Key Specifications

Pinout & Package

CD74HC154E is supplied in a 24-lead plastic dual in-line package (PDIP), 0.600-inch body width, with standard through-hole mounting and JEDEC MS-001AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC154N, CD74HC154E offers extended temperature qualification critical for harsh environments; compared with CD74HCT154E, it provides broader supply range and higher noise immunity - making CD74HC154E the optimal choice for new designs requiring robustness and voltage scalability.

Availability

CD74HC154E is available at Aetrix Electronics and suitable for industrial control systems, aerospace data acquisition modules, and automotive diagnostic tools requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HC154E 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 50 years of innovation in high-reliability logic ICs and industrial-grade components.

The CD74HC154E belongs to TI's High-Speed CMOS Logic family, designed specifically for robust address decoding, signal routing, and digital control applications in demanding environments where wide temperature range, low power, and noise immunity are essential.

FAQ

What is the maximum clock/data frequency supported by CD74HC154E?

The CD74HC154E is not a clocked device but a combinational logic IC. Its usable input transition rate depends on propagation delay and load capacitance. With 50pF load and 4.5V supply, the maximum reliable toggle rate for address inputs is approximately 10MHz (based on 44ns max tPHL/tPLH). For continuous demultiplexing, ensure input rise/fall times ≤500ns at 4.5V to avoid timing violations. The CD74HC154E itself imposes no internal clock limit.

Can CD74HC154E drive LEDs directly without current-limiting resistors?

No - CD74HC154E outputs are not designed for direct LED drive without external current limiting. Each output can sink up to 25mA, but forward voltage drop and LED variability require series resistors to guarantee consistent brightness and prevent exceeding absolute maximum ratings. For example, with a 2V red LED and 5V VCC, a 120Ω resistor limits current to ~25mA. Always verify worst-case VIH/VIL margins when loading outputs.

Is CD74HC154E pin-compatible with CD74HCT154E?

Yes - CD74HC154E and CD74HCT154E share identical 24-pin PDIP mechanical footprint, pin assignment, and functional block diagram. Both have E1, E2, A0–A3, Y0–Y15, VCC, and GND in the same positions. However, they differ electrically: CD74HC154E operates from 2V–6V with CMOS input thresholds, while CD74HCT154E requires 4.5V–5.5V and accepts TTL-level inputs. Swapping them requires verifying supply and signal voltage compatibility.

Does CD74HC154E support cascading for decoding more than 16 lines?

Yes - the CD74HC154E supports cascading via its dual enable inputs. To build a 5-to-32 decoder, connect A4 to E1 of a second CD74HC154E and tie E2 low; use A0–A3 for selection within each group of 16. When A4 = 0, first device is enabled; when A4 = 1, second device activates. This method preserves full decoding functionality without additional logic, and timing remains predictable due to matched propagation delays across the CD74HC154E family.

What is the recommended bypass capacitor value for CD74HC154E?

A 0.1µF ceramic capacitor placed as close as possible to the VCC (pin 24) and GND (pin 12) pins is the industry-standard recommendation for CD74HC154E. This value effectively suppresses high-frequency noise generated during output transitions and maintains stable supply voltage during simultaneous switching of multiple outputs. For systems with heavy I/O activity, adding a bulk 4.7µF tantalum or aluminum electrolytic capacitor nearby further improves low-frequency regulation. Never omit the 0.1µF local bypass - its absence risks metastability and increased EMI.