Texas Instruments CD74HC4515EN

Overview

CD74HC4515EN from Texas Instruments is a high-speed CMOS 4-to-16 line decoder/demultiplexer with input latches, functioning as a binary-to-1-of-16 decoder or 1-to-16 line demultiplexer. It operates from 2V to 6V, features latch enable (LE) and enable (E) control inputs, delivers active-low decoded outputs (Y0–Y15), and supports -55°C to +125°C industrial/military temperature range. It is used in address decoding for memory expansion and I/O port selection in embedded control systems.

For engineers reviewing the CD74HC4515EN datasheet, CD74HC4515EN pinout, CD74HC4515EN application, or CD74HC4515EN equivalent, key selection criteria include its active-low output logic (Yx = LOW when selected), latch-controlled input sampling, E-as-data demultiplexing mode, and compatibility with LSTTL loads (10-unit fanout).

Technical Context

The CD74HC4515EN integrates a 4-bit strobed latch and a 4-to-16 decoder in a single monolithic silicon gate CMOS device. Its latch enable (LE) controls transparent vs. latched input behavior, while the enable (E) input serves dual roles: chip select (active-low) and data input for demultiplexing - when E is used as data, A0–A3 become address lines selecting one of sixteen outputs.

Unlike the CD74HC4514EN (active-high outputs), the CD74HC4515EN asserts selected outputs low (Yx = 0) and holds unselected outputs high (Yx = 1), per truth table. Propagation delays are specified at 47 ns (max, VCC = 6V, CL = 50 pF) from select inputs to outputs and 30 ns (max) from E to outputs, enabling reliable timing in synchronous address/data routing.

Key Specifications

Pinout & Package

CD74HC4515EN is housed 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 (notch/left-index mark side), and the package meets JEDEC MS-001 standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74HC4515EN, CD74HC4514EN offers identical timing and packaging but inverted output polarity, while SN74HC154N removes latch functionality entirely - making CD74HC4515EN uniquely suited for synchronized, noise-immune address decoding in real-time embedded systems.

Availability

CD74HC4515EN is available at Aetrix Electronics and suitable for memory address decoding, industrial I/O expansion, military bus arbitration, and legacy equipment interface adapter designs requiring stable component supply across extended temperature ranges.

Supply support for CD74HC4515EN 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 decades of heritage in high-reliability logic families including HC, HCT, and AHC series.

The CD74HC4515EN belongs to TI's High-Speed CMOS (HC) logic family, designed specifically for low-power, wide-voltage-range, high-noise-immunity digital interfacing in demanding industrial, military, and aerospace applications.

FAQ

What is the key functional difference between CD74HC4515EN and CD74HC4514EN?

The CD74HC4515EN asserts selected outputs LOW (Yx = 0) and holds unselected outputs HIGH, whereas CD74HC4514EN does the opposite: it asserts selected outputs HIGH and holds unselected outputs LOW. Both share identical pinout, timing, latch behavior, and supply specifications - only output polarity differs. This makes CD74HC4515EN ideal for driving active-low chip selects or sinking current in LED/relay interfaces.

Can CD74HC4515EN operate reliably at 3.3V supply voltage?

Yes, CD74HC4515EN is fully specified for 2V to 6V operation, including 3.3V. At VCC = 3.3V, its VIH is 2.31V (70% of VCC) and VIL is 0.99V (30% of VCC), ensuring clean interfacing with 3.3V microcontrollers. Propagation delay remains within 69 ns (max) at 3.3V with 50 pF load, supporting typical embedded timing budgets.

How does the latch enable (LE) pin affect timing behavior in CD74HC4515EN?

When LE is HIGH, CD74HC4515EN operates in transparent mode: outputs respond immediately to changes on A0–A3. When LE transitions LOW, the current address is latched and outputs freeze - even if A0–A3 change afterward. This eliminates glitches during address bus transitions and enables synchronous sampling aligned to system clocks or control strobes.

Is CD74HC4515EN pin-compatible with any industry-standard 4-to-16 decoders?

CD74HC4515EN shares the same 24-pin PDIP footprint and pin assignments as CD74HC4514EN, CD74HC4514M, and CD74HC4515M. However, it is not pin-compatible with SN74HC154N (same function, no latch) or 74LS154 (TTL, different pinout and supply requirements). Always verify LE, E, and output polarity mapping before substitution.

What thermal considerations apply to CD74HC4515EN in continuous operation?

CD74HC4515EN in PDIP (EN) package has θJA = 67°C/W. At maximum ambient +125°C and worst-case power dissipation (~10 mW static + dynamic), junction temperature stays well below the 150°C limit. For sustained high-frequency operation (>1 MHz), ensure adequate PCB copper area and avoid stacking heat-generating components nearby.