Texas Instruments SN74HC253NSR

Overview

SN74HC253NSR from Texas Instruments is a dual 4-line to 1-line data selector/multiplexer with 3-state outputs, designed for bus-oriented digital systems requiring signal routing and parallel-to-serial conversion. 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, CL = 50 pF), and draws ≤80 μA ICC, making it suitable for low-power logic interfacing in industrial control and instrumentation.

For engineers reviewing the SN74HC253NSR datasheet, SN74HC253NSR pinout, SN74HC253NSR application, or SN74HC253NSR equivalent, this page provides verified functional identity, package-specific pin mapping, real-world timing and drive specifications, and validated alternative options for multiplexer-based signal selection in 16-pin SOP designs.

Technical Context

The SN74HC253NSR integrates two independent 4:1 multiplexers with full binary decoding (A/B select lines common to both sections) and individual 3-state output-enable (OE) controls per section. Each section selects one of four data inputs (C0–C3) based on A/B states and drives a single output (Y) with high-impedance capability when OE is high.

Its CMOS HC-family architecture ensures compatibility with TTL loads (up to 15 LSTTL), low input current (≤1 μA), and robust noise immunity via defined VIH/VIL thresholds (e.g., VIH = 3.15 V at VCC = 4.5 V). Switching performance is characterized at CL = 50 pF and CL = 150 pF, with tpd ranging from 13 ns to 60 ns depending on VCC and load.

Key Specifications

Pinout & Package

SOP-16 (NS) package: 6.20 mm × 5.30 mm body, 1.27 mm pitch, 2.00 mm max height, gull-wing leads, pin 1 index area marked.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV253ANSR, SN74HC253NSR offers broader voltage flexibility (2–6 V vs. 1.65–5.5 V) and native 5 V compatibility, while compared with 74HC153D, it eliminates external bus-driving circuitry through integrated 3-state outputs - reducing component count and layout risk in shared-data-path designs.

Availability

SN74HC253NSR is available at Aetrix Electronics and suitable for industrial control, automotive diagnostics, and test equipment applications requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for SN74HC253NSR 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 50 years of innovation in high-reliability digital ICs.

The SN74HC253NSR belongs to TI's 74HC logic family, engineered for robust performance in industrial and commercial environments where wide supply range, low power, and bus-compatible 3-state outputs are essential for signal routing and system integration.

FAQ

What is the maximum clock frequency supported by SN74HC253NSR for reliable data selection?

The SN74HC253NSR does not operate on a clock signal - it is a combinational logic device whose output responds asynchronously to input changes. Its usable data rate is governed by propagation delay (tpd ≤ 38 ns at VCC = 6 V, CL = 50 pF) and enable timing (ten ≤ 21 ns). For reliable operation, input setup/hold times must exceed 5 ns before/after A/B or OE transitions, allowing effective multiplexing up to ~10 MHz in well-designed systems with controlled trace capacitance.

Can SN74HC253NSR interface directly with 3.3 V microcontrollers while powered at 5 V?

Yes, SN74HC253NSR supports mixed-voltage operation: when VCC = 5 V, its inputs are 5 V tolerant and accept 3.3 V logic levels as valid VIH (≥3.15 V) and VIL (≤1.35 V). Outputs swing rail-to-rail (0 V/5 V), so an external level shifter is required if the microcontroller's inputs cannot tolerate 5 V. The SN74HC253NSR itself requires no modification to operate in this configuration.

How does the 3-state output behavior of SN74HC253NSR differ between OE high and OE low states?

When OE is high (logic 1), the corresponding Y output enters high-impedance (Hi-Z) state - effectively disconnecting it from the bus with leakage <±0.5 μA. When OE is low (logic 0), the Y output actively drives high or low based on A/B and C0–C3 inputs. Both sections (1Y and 2Y) have independent OE pins (pin 15 for section 1, pin 1 for section 2), enabling selective bus arbitration without affecting the other channel.

Is SN74HC253NSR pin-compatible with SN74HC153 in the same SOP-16 package?

No - SN74HC253NSR and SN74HC153 are not pin-compatible. While both are dual 4:1 multiplexers, SN74HC253NSR has dedicated OE pins (pins 1 and 15) and separate data inputs for each section, whereas SN74HC153 uses shared data inputs and no OE pins. Their pin mappings differ fundamentally; substituting one for the other requires PCB redesign. Always verify against official TI package drawings before replacement.

What thermal considerations apply to SN74HC253NSR in continuous operation at 6 V?

In SOP-16 (NS) package, SN74HC253NSR has RθJA = 64°C/W. At VCC = 6 V and worst-case ICC = 160 μA (per datasheet max), static power dissipation is ~0.96 mW - resulting in negligible junction temperature rise (<0.1°C). However, dynamic power dominates under switching: with Cpd = 45 pF per section and f = 10 MHz, total dynamic power ≈ 16.2 mW, yielding ΔTJ ≈ 1.0°C. No heatsinking is required for standard operation within –40°C to +85°C ambient.