Texas Instruments SN74ALS253DRG4

Overview

SN74ALS253DRG4 from Texas Instruments is a dual 4-line to 1-line data selector/multiplexer with independent 3-state outputs, designed for bus-organized digital systems. It features two independent 4-input sections (1C0–1C3 and 2C0–2C3), common select inputs (A/B), separate output-enable (1OE/2OE) controls, and operates at 4.5–5.5 V over 0°C to 70°C. It enables parallel-to-serial conversion in TTL-compatible logic circuits.

For engineers reviewing the SN74ALS253DRG4 datasheet, SN74ALS253DRG4 pinout, SN74ALS253DRG4 application, or SN74ALS253DRG4 equivalent, key selection criteria include its dual-section 3-state multiplexing capability, propagation delays as low as 2 ns (data-to-Y), ±24 mA output drive, and SOIC-16 packaging compatible with automated assembly.

Technical Context

The SN74ALS253DRG4 implements two independent 4:1 multiplexer sections sharing binary select lines A and B, each with dedicated output-enable (1OE, 2OE) for high-impedance control. Its internal architecture uses inverters, drivers, and AND-OR logic for full binary decoding and data routing.

Each section drives a single 3-state output (1Y, 2Y) capable of sourcing −2.6 mA or sinking 24 mA at VCC = 4.5 V, supporting direct interface with TTL and CMOS buses. Propagation delay from data input to output is as low as 2 ns (tPLH/tPHL), while enable/disable times (tPZH/tPLZ) range from 2–4 ns under CL = 50 pF conditions.

Key Specifications

Pinout & Package

SN74ALS253DRG4 is packaged in a 16-pin SOIC (D package), 3.9 mm wide, with 1.27 mm pitch and RoHS-compliant NiPdAu lead finish. Pin 1 is located in quadrant Q1 per tape-and-reel orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ALS253N, SN74ALS253DRG4 provides identical functionality in surface-mount form for automated assembly, while SN74AS253AD trades higher static current for significantly reduced propagation delay - making SN74ALS253DRG4 the optimal choice for cost-sensitive, medium-speed commercial applications requiring proven reliability and RoHS compliance.

Availability

SN74ALS253DRG4 is available at Aetrix Electronics and suitable for microprocessor bus expansion, industrial PLC I/O multiplexing, and digital test equipment signal routing requiring stable component supply and long-term manufacturability.

Supply support for SN74ALS253DRG4 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 over 90 years of innovation in industrial, automotive, and communications markets.

The SN74ALS253DRG4 belongs to TI's legacy ALS (Advanced Low-Power Schottky) logic family, engineered for reliable, low-power, high-speed TTL-compatible operation in commercial-grade digital systems.

FAQ

What is the maximum clock frequency supported by SN74ALS253DRG4?

The SN74ALS253DRG4 does not operate on a clock signal - it is a combinational logic device whose speed is defined by propagation delay. With a minimum data-to-output delay of 2 ns and maximum of 10 ns (at VCC = 4.5–5.5 V, CL = 50 pF), it supports effective data switching rates up to approximately 100 MHz in synchronous bus applications. Timing margins must account for setup/hold requirements of downstream latches.

Does SN74ALS253DRG4 support mixed-voltage interfacing (e.g., 3.3 V logic inputs)?

No - SN74ALS253DRG4 is a 5-V-only device with TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max). Applying 3.3 V logic signals may result in marginal or unreliable recognition of HIGH levels. For 3.3 V systems, level-shifting circuitry or a 3.3 V–compatible multiplexer such as SN74LVC253A is required. The SN74ALS253DRG4 itself must be powered at 4.5–5.5 V.

Can SN74ALS253DRG4 outputs drive LEDs directly?

Yes - each 3-state output of SN74ALS253DRG4 can sink up to 24 mA (IOL = 24 mA at VCC = 4.5 V), sufficient to drive standard indicator LEDs with appropriate current-limiting resistors. For example, with a 2 V LED forward voltage and 5 V supply, a 120 Ω resistor yields ~25 mA. However, sustained 24 mA operation requires attention to thermal dissipation in the SOIC-16 package, especially when multiple outputs are active simultaneously.

Is SN74ALS253DRG4 pin-compatible with SN74LS253?

Yes - SN74ALS253DRG4 is functionally and pinout-compatible with SN74LS253, sharing identical pin assignments, logic behavior, and DC electrical characteristics (VIH/VIL, VOH/VOL). Key improvements include lower ICC (6.5 mA vs. ~15 mA), enhanced noise immunity (VIK = −1.5 V), and tighter AC timing (2–10 ns vs. 3–15 ns propagation). No PCB changes are required for drop-in replacement in existing LS-based designs.

What is the meaning of "DRG4" in SN74ALS253DRG4?

The suffix "DRG4" denotes Texas Instruments' packaging and ordering variant: "D" = SOIC-16 package, "R" = tape-and-reel packaging (2500 units per reel), "G4" = green (RoHS-compliant) finish with NiPdAu lead plating and Level-1 moisture sensitivity rating (unlimited floor life at ≤30°C/60% RH). This distinguishes it from tube-packaged (N), ceramic (J/FK), or non-RoHS variants.