Texas Instruments CD74HC4515M

Overview

CD74HC4515M from Texas Instruments is a high-speed CMOS 4-to-16 line decoder/demultiplexer with input latches, configured as active-low output (Y0–Y15 asserted low), operating from 2V to 6V, rated for -55°C to +125°C, and packaged in 24-pin SOIC. It performs binary-to-1-of-16 decoding and 1-to-16 demultiplexing in industrial control logic, address selection for memory-mapped peripherals, and programmable logic interface routing.

For engineers reviewing the CD74HC4515M datasheet, CD74HC4515M pinout, CD74HC4515M application, or CD74HC4515M equivalent, key selection criteria include its latch-enable-controlled output hold behavior, E-input-as-data capability for demux mode, guaranteed propagation delay ≤83 ns at 4.5V, and compatibility with LSTTL loads (10-unit fanout) in extended temperature environments.

Technical Context

The CD74HC4515M integrates a 4-bit strobed latch and 4-to-16 decoder in a single silicon gate CMOS device. Its latch enable (LE) controls transparent vs. latched operation: when LE = HIGH, outputs follow A0–A3 inputs; when LE = LOW, outputs freeze at their prior state (LOW for CD74HC4515M, unlike CD74HC4514M's HIGH-active outputs).

Demultiplexing is implemented by using the E (enable) input as the data path while A0–A3 serve as address lines; E = LOW enables one output, E = HIGH forces all outputs HIGH (inactive). The device supports cascading via E as chip select and exhibits balanced tPHL/tPLH transition times and noise immunity of 30% VCC at 5V.

Key Specifications

Pinout & Package

CD74HC4515M is housed in a 24-pin SOIC (DW) package with 1.27 mm pitch, JEDEC MS-013 compliant, moisture sensitivity level 1, and RoHS-compliant NiPdAu lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74HC4514M, CD74HC4515M provides native active-low outputs ideal for chip select and reset generation, while SN74LV4015N lacks both latch capability and 16-output density-making CD74HC4515M uniquely suited for temperature-robust, latched 4-to-16 decoding in space-constrained industrial designs.

Availability

CD74HC4515M is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, microcontroller peripheral address decoding, and test equipment signal routing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74HC4515M 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 delivering analog, embedded processing, and logic solutions with emphasis on reliability, longevity, and industrial-grade qualification.

CD74HC4515M belongs to TI's HC-series high-speed CMOS logic family, designed specifically for robust, low-power, wide-temperature digital interfacing in harsh-environment control systems.

FAQ

What is the key functional difference between CD74HC4515M and CD74HC4514M?

The CD74HC4515M asserts selected outputs LOW (active-low), while CD74HC4514M asserts them HIGH (active-high). Both share identical pinout, latch behavior, timing specs, and temperature rating. This polarity difference determines compatibility with downstream enable/reset logic: CD74HC4515M directly drives active-low chip selects, whereas CD74HC4514M suits active-high LED indicators or buffers. The CD74HC4515M truth table confirms Yx = LOW when addressed and E = LOW.

Does CD74HC4515M support true demultiplexing, and how is it configured?

Yes, CD74HC4515M supports true 1-to-16 demultiplexing by using the E input as the data line and A0–A3 as address lines. When LE = HIGH, changes at E propagate to the selected Yx output determined by A0–A3. This mode is explicitly documented in the functional description and truth table. No external components are needed-demux operation is inherent to the CD74HC4515M architecture and requires only proper LE and E signal timing per datasheet setup/hold requirements.

What is the maximum clock/data rate supported by CD74HC4515M in decoder mode?

The CD74HC4515M does not operate on a clock signal-it is combinational logic with latch control. Its speed is governed by propagation delay: at 4.5V and -40°C to +85°C, tPHL/tPLH is ≤69 ns (max) from A0–A3 or E to any Yx output. This supports reliable address decoding for systems with address valid windows >70 ns, corresponding to effective toggle rates up to ~7 MHz under worst-case conditions. The CD74HC4515M datasheet specifies no minimum pulse width for address inputs beyond setup/hold timing relative to LE.

Can CD74HC4515M be used in cascaded configurations, and what is required?

Yes, CD74HC4515M supports cascading via its E (enable) input. To expand beyond 16 outputs, connect E of downstream devices to decoded outputs of upstream units (e.g., Y0–Y3 of first CD74HC4515M drive E of four additional CD74HC4515M units). All devices share common A0–A3 and LE. This yields 64 total outputs using six CD74HC4515M devices. The datasheet confirms this topology and specifies that E serves as chip select when cascaded-no additional logic is required for hierarchical decoding.

Is CD74HC4515M pin-compatible with legacy TTL 74LS4515 or 74S4515 devices?

No, CD74HC4515M is not pin-compatible with 74LS4515 or 74S4515. Those TTL parts use 24-pin ceramic DIP packages with different pin assignments-for example, 74LS4515 places GND at pin 12 and VCC at pin 24, whereas CD74HC4515M places GND at pin 12 and VCC at pin 16. Additionally, CD74HC4515M uses SOIC (DW) packaging, and its logic thresholds, drive strength, and timing differ fundamentally. Direct replacement requires PCB redesign and validation of voltage-level and timing margins.