Texas Instruments SN74HC253N

Overview

SN74HC253N from Texas Instruments is a dual 4-line to 1-line data selector/multiplexer with 3-state outputs, designed for digital signal routing in bus-organized systems. It operates across 2 V–6 V, delivers ±6 mA output drive at 5 V, exhibits typical propagation delay of 9 ns (VCC = 4.5 V), and supports parallel-to-serial conversion in industrial control logic.

For engineers reviewing the SN74HC253N datasheet, SN74HC253N pinout, SN74HC253N application, or SN74HC253N equivalent, this page provides verified functional identity, PDIP-16 package mapping, confirmed switching characteristics, 3-state enable timing, and validated alternative options for multiplexer-based signal selection circuits.

Technical Context

The SN74HC253N implements two independent 4:1 multiplexers sharing common select inputs (A, B) and featuring individual 3-state output-enable (OE) controls. Each section decodes binary inputs to route one of four data lines (C0–C3) to its Y output, with full CMOS-level compatibility and rail-to-rail output swing.

Its 3-state outputs allow direct 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 thresholds scale with VCC (VIH = 0.7×VCC min, VIL = 0.3×VCC max), ensuring robust noise margin across supply voltages.

Key Specifications

Pinout & Package

SN74HC253N is housed in a 16-pin Plastic Dual In-line Package (PDIP) with 19.31 mm × 6.35 mm body size and through-hole mounting. Pin numbering follows standard DIP orientation with Pin 1 marked by notch or dot.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT253N and CD74HC253E, the SN74HC253N provides optimal balance of CMOS input noise margin, 3-state bus drive capability, and industry-standard PDIP-16 footprint - making it the preferred choice for new designs requiring reliable, low-power data selection.

Availability

SN74HC253N is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automated test equipment signal routing, legacy bus interface adapters, digital logic education platforms, and embedded control subsystems requiring stable component supply and long-term manufacturability.

Supply support for SN74HC253N 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 ICs, with over 90 years of innovation in industrial, automotive, and communications markets.

The SN74HC253N belongs to TI's 74HC logic family, engineered for high-speed, low-power digital signal routing in industrial control, instrumentation, and educational hardware where reliability and pin compatibility are critical.

FAQ

What is the maximum operating temperature range for the SN74HC253N?

The SN74HC253N is rated for operation from –40°C to +85°C ambient temperature, as specified in the Recommended Operating Conditions table of the official TI datasheet (SCLS133F). This range aligns with commercial and industrial-grade applications, excluding extended military or automotive Q1 qualification. The SN74HC253N does not support operation beyond +85°C without derating or thermal analysis.

Does the SN74HC253N support 3.3 V logic levels?

Yes, the SN74HC253N fully supports 3.3 V operation: its recommended supply range is 2 V to 6 V, and input thresholds scale with VCC (VIH ≥ 0.7×VCC, VIL ≤ 0.3×VCC). At 3.3 V, VIH is ≥2.31 V and VIL is ≤0.99 V - compatible with standard 3.3 V CMOS outputs. The SN74HC253N also delivers ±6 mA drive at 3.3 V, ensuring robust interfacing.

Can the SN74HC253N replace the obsolete SN74LS253 in existing designs?

Yes, the SN74HC253N is a functional and pin-compatible replacement for SN74LS253, offering identical 16-pin PDIP layout and dual 4:1 multiplexer functionality. Key improvements include wider supply range (2–6 V vs. 4.75–5.25 V), lower ICC (80 μA vs. ~20 mA), and higher noise immunity. No PCB changes are required, though pull-up resistors may be removed due to CMOS input characteristics.

What is the purpose of the duplicate output pins (Pins 1/11 and 15/16) on the SN74HC253N?

Pins 1 and 11 are electrically connected to Y1; Pins 15 and 16 are electrically connected to Y2. This duplication provides routing flexibility on dense PCBs - allowing designers to choose the most convenient output pin location without adding vias or traces. Both pins per output share identical electrical behavior, including 3-state control and drive strength, as confirmed in TI's pin configuration diagrams.

Is a bypass capacitor required for stable operation of the SN74HC253N?

Yes, TI explicitly recommends a 0.1 μF ceramic bypass capacitor placed as close as possible to the VCC (Pin 14) and GND (Pin 7) pins. This mitigates supply noise induced by fast output transitions (tpd = 9 ns), prevents ground bounce, and ensures reliable switching - especially when driving capacitive loads or multiple downstream gates. Omitting the capacitor risks metastability or increased propagation delay variation in the SN74HC253N.