Texas Instruments SN74ALS153D

Overview

SN74ALS153D from Texas Instruments is a dual 1-of-4 data selector/multiplexer IC with independent strobe (enable) inputs per section, operating at 4.5–5.5 V over 0°C to 70°C, delivering 24 mA low-level output drive and 21 ns max propagation delay for data-to-output paths. It performs parallel-to-serial conversion and supports cascading via dedicated G inputs in industrial control logic and address decoding applications.

For engineers reviewing the SN74ALS153D datasheet, SN74ALS153D pinout, SN74ALS153D application, or SN74ALS153D equivalent, key selection considerations include its ALS family speed-power trade-off, dual-section independent enable architecture, SOIC-16 package compatibility, and TTL-compatible input thresholds with guaranteed 2.4 V VOH at −2.6 mA.

Technical Context

The SN74ALS153D implements two independent 4-input multiplexers sharing common select lines A and B, each with dedicated active-low strobe (1G, 2G) enabling full binary decoding to AND-OR gates. Its internal structure includes inverters and drivers for full logic-level restoration.

It operates strictly in positive-logic TTL-compatible mode: VIH = 2.0 V min, VIL = 0.8 V max, VOH = 2.4 V min at −2.6 mA, VOL = 0.4 V max at 24 mA. Propagation delays are asymmetric-tPLH/tPHL differ by up to 3 ns depending on input transition type (select vs. data vs. strobe).

Key Specifications

Pinout & Package

SN74ALS153D uses a 16-pin SOIC (D) package with 1.27 mm pitch, 3.9 mm body width, and 1.75 mm maximum height. Pin numbering follows standard D-package top-view orientation with pin 1 marked by beveled corner or notch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual 4:1 multiplexer applications.

Compared with SN74ALS153N and SN74AS153NSR, the SN74ALS153D offers optimal balance of speed, power, and SMT manufacturability for cost-sensitive industrial control boards - it avoids the thermal and layout penalties of DIP while delivering lower static power than AS-series alternatives.

Availability

SN74ALS153D is available at Aetrix Electronics and suitable for industrial control panels, legacy system upgrades, and test instrumentation requiring stable component supply and long-term obsolescence management.

Supply support for SN74ALS153D 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic ICs with broad industrial and automotive qualification.

The SN74ALS153D belongs to TI's legacy 74ALS logic family, designed specifically for high-reliability commercial and industrial systems needing predictable TTL-compatible timing and robust noise immunity without 3-state complexity.

FAQ

What is the maximum clock rate supported by SN74ALS153D in a data routing application?

The SN74ALS153D does not operate on a clock signal - it is combinatorial logic. Its maximum usable data rate depends on propagation delay and system setup/hold timing. With 21 ns max tPHL and typical 10 ns tPLH, it supports reliable routing of signals with ≤25 MHz toggle rates when interfaced to microcontrollers or FPGAs with adequate timing margins. The SN74ALS153D must be used with synchronous enable strobing to avoid glitches during select transitions.

Does SN74ALS153D support 3-state (high-impedance) outputs?

No, the SN74ALS153D features totem-pole (push-pull) outputs only - it lacks 3-state capability. Unlike the ′ALS253 or SN74AS253A, this device cannot be directly wired-OR'd or shared on a bus. Outputs are always driven high or low. If bus sharing is required, external tri-state buffers or a different part number such as SN74ALS253DR must be used instead of the SN74ALS153D.

Can SN74ALS153D operate at 3.3 V supply voltage?

No, the SN74ALS153D is specified only for 4.5 V to 5.5 V operation. At 3.3 V, VIH threshold (2.0 V min) becomes unmet by most 3.3 V logic families, and VOH drops below 2.4 V - violating TTL compatibility. Attempting 3.3 V operation risks unreliable switching, increased static current, and potential latch-up. For 3.3 V systems, consider SN74LVC153 or SN74AHC153 instead of the SN74ALS153D.

What is the meaning of "strobe" in SN74ALS153D functionality?

In the SN74ALS153D, "strobe" refers to the active-low enable inputs (1G and 2G) that gate each 4:1 multiplexer section independently. When a strobe is high, the corresponding output (1Y or 2Y) is forced to a defined logic low level - not high-impedance. This differs from 3-state strobes; here, strobe disables data selection and asserts a known state, enabling priority encoding or forced default output behavior in the SN74ALS153D.

How does SN74ALS153D differ from SN74LS153 in practical design?

The SN74ALS153D delivers 3× faster propagation (21 ns vs. 60 ns max), 50% lower ICC (14 mA vs. 28 mA), and improved noise margins versus SN74LS153, due to Advanced Low-Power Schottky technology. Its tighter VOL spec (0.4 V vs. 0.5 V) and higher IOL (24 mA vs. 8 mA) allow direct driving of more downstream loads. These advantages make the SN74ALS153D preferable in timing-critical or power-constrained designs where LS-family parts would require speed-grade derating or additional buffering.