NXP Semiconductors 74HCT4515D,653

Overview

74HCT4515D,653 from Nexperia is a 4-to-16 line inverting decoder/demultiplexer with input latches, operating at 4.5 V supply, featuring 26 ns typical propagation delay (An to Qn), standard output drive capability, and active-LOW mutually exclusive outputs (Q0–Q15). It serves as an address decoder in microcontroller peripheral expansion systems where latch-stable output selection is required under asynchronous control.

For engineers reviewing the 74HCT4515D,653 datasheet, 74HCT4515D,653 pinout, 74HCT4515D,653 application, or 74HCT4515D,653 equivalent, key selection considerations include latch enable timing (tW ≥ 16 ns min), E-input propagation (18–60 ns), HCT-compatible TTL-level inputs, and SO16 package compatibility with legacy 4000B-series layouts.

Technical Context

The 74HCT4515D,653 implements a synchronous latch + combinational decode architecture: when LE is HIGH, outputs follow A0–A3 in real time; when LE transitions LOW, the current address is captured and held independently of subsequent address changes. The enable input E operates asynchronously - its state directly controls output activation without affecting latch contents.

All 16 outputs are inverting and mutually exclusive: only one Qn is LOW at any valid E = LOW condition, determined solely by the latched A0–A3 value. Input thresholds comply with TTL logic levels (VIH = 2.0 V min, VIL = 0.8 V max), ensuring interoperability with 5 V microcontrollers and legacy logic families.

Key Specifications

Pinout & Package

74HCT4515D,653 is housed in a 24-pin Small Outline (SO) package (SO24), 7.5 mm body width, with 0.65 mm lead pitch and surface-mount gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar decoder/demultiplexer applications.

Compared with 74HCT4515D,653, the 74HC4515D,653 offers lower static power but demands higher input voltage margins, while the SN74LS4515N delivers faster worst-case timing but increases board-level power and heat dissipation - trade-offs that directly impact thermal design and supply rail stability in dense layouts.

Availability

74HCT4515D,653 is available at Aetrix Electronics and suitable for memory address decoding, peripheral select logic, hexadecimal display driving, and legacy system bus expansion requiring stable component supply and long-term industrial availability.

Supply support for 74HCT4515D,653 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

Nexperia is a global leader in high-volume production of logic, discrete, and power MOSFET semiconductors, serving automotive, industrial, computing, and consumer markets with AEC-Q101-qualified components and robust supply chain infrastructure.

The 74HCT4515D,653 belongs to Nexperia's 74HCT logic family, engineered for seamless interoperability with TTL-based microcontrollers and legacy digital systems while delivering CMOS efficiency and reliability.

FAQ

What is the function of the LE pin on the 74HCT4515D,653?

The LE (Latch Enable) pin on the 74HCT4515D,653 controls data capture behavior: when LE is HIGH, outputs Q0–Q15 follow A0–A3 in real time; when LE transitions LOW, the current address is latched and held regardless of further changes to A0–A3. This allows synchronization with system timing without requiring a clock signal, making the 74HCT4515D,653 ideal for bus-critical applications like memory decoding where address stability during strobe windows is essential.

Can the 74HCT4515D,653 operate at 3.3 V supply?

No, the 74HCT4515D,653 is specified only for 4.5 V to 5.5 V operation per its HCT-family design. Its TTL-compatible input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V) and internal circuitry require minimum 4.5 V to guarantee correct logic levels and timing performance. Using 3.3 V may result in undefined outputs, increased propagation delay, or failure to meet AC specifications - the 74HCT4515D,653 must be operated within its rated VCC range to ensure functional reliability.

How does the E input differ from LE in the 74HCT4515D,653?

In the 74HCT4515D,653, E (Enable) is an asynchronous active-LOW control that gates output activation: when E = HIGH, all Q0–Q15 are forced HIGH regardless of latch state; when E = LOW, the latched address determines which single output goes LOW. LE (Latch Enable), in contrast, is synchronous and controls whether A0–A3 are transparently passed or stored - E does not affect the latch contents. This separation allows independent control of output enable timing and address sampling in the 74HCT4515D,653.

Is the 74HCT4515D,653 pin-compatible with older 4000B-series decoders?

Yes, the 74HCT4515D,653 is explicitly designed as a pin-compatible upgrade for the CD4515B in SO24 packaging, maintaining identical pin assignments for A0–A3, LE, E, Q0–Q15, VCC, and GND. This allows direct replacement in existing designs without PCB modification, provided the 4.5–5.5 V supply and HCT-level timing constraints of the 74HCT4515D,653 are met - a key advantage over non-pin-compatible alternatives.

What is the maximum operating temperature range for the 74HCT4515D,653?

The 74HCT4515D,653 is qualified for industrial operation from −40 °C to +85 °C, with extended characterization up to +125 °C for certain AC parameters. Its guaranteed performance - including propagation delays, setup/hold times, and output drive - is fully specified across the −40 °C to +85 °C range, making the 74HCT4515D,653 suitable for demanding environments such as factory automation controllers and outdoor instrumentation where thermal stability is critical.