Texas Instruments SN74HC257PWR

Overview

SN74HC257PWR from Texas Instruments is a quadruple 2-line to 1-line data selector/multiplexer with non-inverted 3-state outputs, operating from 2 V to 6 V supply, delivering 9 ns typical propagation delay at 4.5 V, ±6 mA output drive at 5 V, and 80 µA max ICC - used for bus interface and signal routing in digital logic systems.

For engineers reviewing the SN74HC257PWR datasheet, SN74HC257PWR pinout, SN74HC257PWR application, or SN74HC257PWR equivalent, key selection criteria include its TSSOP-16 package, 3-state enable control (G), identical A/B select logic across four channels, and compatibility with LSTTL loads in mixed-voltage logic designs.

Technical Context

The SN74HC257PWR implements four independent 2:1 multiplexers sharing common address inputs (A/B) and an active-low 3-state enable (G). Each channel selects between two input sources (A or B) and drives a dedicated non-inverting output (Y), entering high-impedance state when G is high.

Its CMOS design ensures low static current (≤100 nA at 6 V), rail-to-rail output swing, and robust noise immunity across −40°C to +85°C operation. Input transition times are specified up to 1000 ns at 2 V, supporting slow-edge or legacy system interfacing without timing violation.

Key Specifications

Pinout & Package

TSSOP-16 package (PW), 5.00 mm × 4.40 mm body size, 1.2 mm max height, 0.65 mm pitch, RoHS-compliant NiPdAu/Sn lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 2:1 multiplexer applications.

Compared with SN74HC258PWR and SN74LVC157APWR, the SN74HC257PWR provides non-inverted signal routing across 2–6 V operation - making it uniquely suitable for voltage-flexible bus arbitration where output polarity must match input logic states without inversion.

Availability

SN74HC257PWR is available at Aetrix Electronics and suitable for industrial control logic, embedded bus expansion, digital test equipment, and legacy interface adapter applications requiring stable component supply and long-term production continuity.

Supply support for SN74HC257PWR 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 SN74HC257PWR belongs to TI's industry-standard 74HC logic family, designed for robust, low-power, wide-voltage digital signal routing in cost-sensitive and reliability-critical applications.

FAQ

What is the maximum operating temperature for the SN74HC257PWR?

The SN74HC257PWR is rated for operation from −40°C to +85°C ambient temperature. This industrial temperature range is validated per TI's recommended operating conditions and thermal metrics (RθJA = 108°C/W for TSSOP-16), ensuring reliable performance in factory automation and outdoor electronics environments where thermal cycling occurs.

Does the SN74HC257PWR support 3.3 V operation?

Yes, the SN74HC257PWR fully supports 3.3 V operation within its 2 V to 6 V supply range. At VCC = 3.3 V, it delivers guaranteed VOH ≥ 3.15 V and VOL ≤ 0.1 V under load, meeting 3.3 V LVTTL logic thresholds and enabling direct interface with FPGAs, microcontrollers, and other 3.3 V logic without level translation.

How does the enable (G) pin function on the SN74HC257PWR?

The G pin on the SN74HC257PWR is an active-low 3-state enable. When G = HIGH, all four Y outputs enter high-impedance mode regardless of A/B states - isolating the device from the bus. When G = LOW, outputs respond to A/B inputs. TI recommends tying G to VCC via a pull-up resistor during power-up to ensure safe default isolation.

Can the SN74HC257PWR replace the SN74HC258PWR in a design?

No - the SN74HC257PWR cannot directly replace the SN74HC258PWR because their outputs have opposite polarity: SN74HC257PWR has non-inverted outputs, while SN74HC258PWR has inverted outputs. Swapping them would invert all four Y signals, breaking functional correctness unless compensated by upstream logic inversion.

What is the recommended bypass capacitor for the SN74HC257PWR?

Texas Instruments specifies a 0.1 µF ceramic capacitor placed as close as possible to the VCC (Pin 16) and GND (Pin 8) pins of the SN74HC257PWR. This minimizes high-frequency supply noise and prevents ground bounce during output transitions - especially critical when driving multiple LSTTL loads or operating above 10 MHz toggle rates.