Texas Instruments SN74HC253DR

Overview

SN74HC253DR from Texas Instruments is a dual 4-line to 1-line data selector/multiplexer with 3-state outputs, implementing full binary decoding for independent channel selection in digital logic systems. It operates from 2 V to 6 V, delivers ±6 mA output drive at 5 V, exhibits typical propagation delay of 9 ns, and supports bus-oriented applications via high-impedance outputs. It is used in parallel-to-serial conversion and multiplexed data routing in industrial control and instrumentation interfaces.

For engineers reviewing the SN74HC253DR datasheet, SN74HC253DR pinout, SN74HC253DR application, or SN74HC253DR equivalent, this page provides verified functional identity, SOIC-16 package mapping, confirmed switching and DC electrical characteristics, and validated alternative parts for logic-level signal routing designs requiring dual 4:1 selection with 3-state control.

Technical Context

The SN74HC253DR integrates two independent 4:1 multiplexers sharing common select inputs (A/B) but featuring separate 3-state output-enable (OE) controls per channel. Each section uses AND-OR gating with inverters and drivers for full binary decoding, enabling deterministic selection of one of four data inputs (C0–C3) per section.

Its 3-state outputs support bidirectional bus interfacing: when OE is high, the output enters high-impedance state; when low, it drives logic-high or logic-low with ±6 mA capability at 5 V. Input transition times are specified down to 400 ns (VCC = 6 V), and ICC remains ≤80 μA max across the operating range.

Key Specifications

Pinout & Package

SN74HC253DR is housed in a 16-pin SOIC (D) package with nominal body size 9.90 mm × 3.90 mm and maximum height 2.00 mm. Pin numbering follows JEDEC MS-012 standard for SOIC-16.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC153DR, SN74HC253DR adds essential 3-state control for bus arbitration; compared with CD74HC253M96, it offers identical performance with TI-specific packaging and traceability - making it optimal for new designs requiring documented supply chain continuity.

Availability

SN74HC253DR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, test equipment signal routing, embedded serial interface bridging, and legacy bus interface adaptation requiring stable component supply and long-term production support.

Supply support for SN74HC253DR 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 SN74HC253DR belongs to TI's 74HC logic family, designed for high-speed, low-power CMOS applications where pin-compatible upgrades from TTL and robust noise immunity are required in harsh electromagnetic environments.

FAQ

What is the maximum operating frequency supported by SN74HC253DR?

The SN74HC253DR does not specify a maximum clock frequency, but its typical propagation delay of 9 ns at VCC = 4.5 V implies reliable operation up to approximately 110 MHz for data enable/disable timing. System-level maximum frequency depends on setup/hold times of connected devices and PCB trace integrity - design validation at target speed is recommended using the switching characteristics table in the official datasheet.

Does SN74HC253DR support mixed-voltage operation between inputs and outputs?

Yes, SN74HC253DR supports mixed-voltage operation: inputs are 5-V tolerant up to VCC + 0.5 V, and outputs swing rail-to-rail within the VCC range (2 V–6 V). When interfacing with 3.3 V controllers and 5 V peripherals, ensure VCC is set to the higher voltage (e.g., 5 V) and verify input thresholds meet VIH/VIL requirements for the driving device - no level-shifting circuitry is needed for basic logic-level translation.

How are the two multiplexer sections of SN74HC253DR controlled independently?

The two multiplexer sections of SN74HC253DR share common select inputs A and B (pins 15 and 14) for binary address decoding, but each has its own dedicated 3-state output-enable input: 1OE (pin 9) controls output 1Y (pin 8), and 2OE (pin 10) controls output 2Y (pin 9). This allows independent bus arbitration - one section can drive while the other remains high-impedance, enabling time-multiplexed or conditional routing without changing address lines.

Can SN74HC253DR replace SN74LS253 in existing designs?

SN74HC253DR can replace SN74LS253 in most cases due to identical pinout and function, but requires attention to supply voltage (LS uses 5 V only; HC supports 2–6 V) and output drive (HC provides ±6 mA vs. LS's ±8 mA). Input thresholds differ: HC has higher noise margin at 5 V. No PCB changes are needed, but verify timing margins - HC's faster tpd may require adjusting setup/hold windows in legacy LS-timed systems.

What thermal considerations apply to SN74HC253DR in continuous operation?

SN74HC253DR in SOIC-16 package has a junction-to-ambient thermal resistance (RθJA) of 73°C/W. At maximum ICC (80 μA) and worst-case output loading, power dissipation remains below 10 mW - resulting in negligible self-heating (<1°C rise). No heatsinking is required; however, maintain ≥2 mm clearance from adjacent heat sources and ensure adequate airflow in enclosed industrial enclosures per IPC-2221 guidelines.