Texas Instruments CD74HC4514EG4

Overview

CD74HC4514EG4 from Texas Instruments is a high-speed CMOS 4-to-16 line decoder/demultiplexer with input latches, functioning as both binary-to-1-of-16 decoder and 1-to-16 line demultiplexer. It operates from 2V to 6V, features latch enable (LE) and active-low enable (E), delivers propagation delay of 47ns (typ, VCC = 6V), and supports industrial temperature range −55°C to +125°C. It is used in address decoding for memory expansion and I/O port selection in embedded control systems.

For engineers reviewing the CD74HC4514EG4 datasheet, CD74HC4514EG4 pinout, CD74HC4514EG4 application, or CD74HC4514EG4 equivalent, key selection considerations include latch-controlled output stability, E-input dual-role as data input (demux mode) and chip select (cascaded mode), fanout capability of 10 LSTTL loads, and compatibility with HC logic family noise margins (NIL/NIH = 30% of VCC at 5V).

Technical Context

The CD74HC4514EG4 integrates a 4-bit strobed latch and a 4-to-16-line decoder in a single monolithic silicon gate CMOS device. Its latch enable (LE) controls transparent vs. latched behavior: when LE is high, outputs follow A0–A3 inputs; when LE is low, outputs hold their prior state (high for CD74HC4514, low for CD74HC4515). The active-low enable (E) gates all outputs - low enables decoding/demuxing, high forces all outputs inactive.

Demultiplexing is implemented by routing data to E while using A0–A3 as address lines; cascading uses E as chip-select input. Propagation delays are tightly balanced (tPHL ≈ tPLH), and transition times are controlled to minimize skew - critical for synchronous address decoding in multi-chip systems operating up to 20 MHz (at VCC = 6V, CL = 15pF).

Key Specifications

Pinout & Package

CD74HC4514EG4 is supplied in a 24-pin plastic dual-in-line package (PDIP) with 0.600-inch body width and through-hole mounting. Pin 1 is located at the top-left corner with notch or dot marking; pin numbering proceeds counter-clockwise.

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 CD74HC4515EN, CD74HC4514EG4 uniquely combines latched inputs, active-high outputs, and E-input dual-mode operation - making it the only option supporting both synchronous address capture and demultiplexing within a single 24-pin PDIP package.

Availability

CD74HC4514EG4 is available at Aetrix Electronics and suitable for memory address decoding, industrial I/O expansion, aerospace avionics bus interface, and test equipment signal routing requiring stable component supply across extended temperature ranges.

Supply support for CD74HC4514EG4 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 ICs, with over 90 years of innovation in high-reliability and industrial-grade components.

The CD74HC4514EG4 belongs to TI's HC (High-Speed CMOS) logic family, designed for low-power, high-noise-immunity digital interfacing in demanding environments including automotive, defense, and industrial automation.

FAQ

What is the function of the LE pin on the CD74HC4514EG4?

The LE (Latch Enable) pin on the CD74HC4514EG4 controls whether the internal 4-bit latch is transparent or holding. When LE is high, outputs Y0–Y15 follow A0–A3 inputs in real time; when LE is low, outputs retain their last valid state. This behavior prevents glitches during address transitions and enables synchronous capture of bus addresses in microcontroller systems - a key differentiator from non-latching decoders like the SN74HC154N. The CD74HC4514EG4 relies on LE for deterministic timing in memory-mapped I/O applications.

Can CD74HC4514EG4 operate at 3.3V supply voltage?

Yes, CD74HC4514EG4 operates across 2V to 6V, fully supporting 3.3V nominal supply. At VCC = 3.3V, VIH is guaranteed ≥2.0V and VIL ≤1.0V, providing adequate noise margin for interfacing with 3.3V microcontrollers and FPGAs. Propagation delay increases to ~75ns (typ) versus 47ns at 6V, but remains compatible with most 3.3V system timing budgets. The CD74HC4514EG4 maintains its full −55°C to +125°C temperature specification at 3.3V, unlike some older logic families that derate performance below 4.5V.

How does the E pin function differently in decoder vs. demultiplexer mode for CD74HC4514EG4?

In decoder mode, the E pin acts as an active-low enable: only when E = LOW do outputs respond to A0–A3; E = HIGH forces all outputs LOW. In demultiplexer mode, E becomes the serial data input - the value present at E when LE is high is routed to the Y_n output selected by A0–A3. This dual role eliminates need for external gating logic and allows the same CD74HC4514EG4 to serve both address decoding and data distribution functions. Cascading multiple CD74HC4514EG4 devices uses E as chip-select, further extending functionality.

Is CD74HC4514EG4 pin-compatible with CD74HC4515EN?

Yes, CD74HC4514EG4 and CD74HC4515EN share identical pinout, package (24-pin PDIP), and electrical timing specifications - differing only in output polarity: CD74HC4514EG4 asserts selected outputs HIGH, while CD74HC4515EN asserts them LOW. This makes them direct drop-in replacements where logic polarity can be accommodated in downstream circuitry. Both parts use the same LE, E, A0–A3 interface and support identical cascading and demux configurations. The CD74HC4514EG4 and CD74HC4515EN are explicitly documented as functional variants in TI's datasheet SCHS280C.

What is the maximum clock/data rate supported by CD74HC4514EG4 in demultiplexer applications?

The CD74HC4514EG4 supports demultiplexer operation up to approximately 20 MHz when VCC = 6V and load capacitance is 15pF, based on its 19ns typical output transition time and 30ns propagation delay (E → Y). At 50pF load, maximum usable frequency drops to ~12 MHz due to increased delay (45ns typ). System-level rate depends on setup/hold timing of LE and address inputs - minimum LE pulse width is 16ns at 6V. For reliable high-speed demuxing, the CD74HC4514EG4 requires clean, slew-rate-controlled inputs and localized decoupling; its performance is validated across the full −55°C to +125°C range.