Nexperia USA Inc. 74AHCT257PW,112

Overview

74AHCT257PW,112 from Nexperia is a quad 2-input multiplexer with 3-state outputs and TTL-compatible inputs, operating from 4.5 V to 5.5 V supply. It features overvoltage-tolerant inputs (up to 5.5 V), Schmitt-trigger inputs for noise immunity, and supports mixed-voltage signal routing in industrial control logic. Its 16-pin TSSOP package enables high-density PCB layout in data path selection applications.

For engineers reviewing the 74AHCT257PW,112 datasheet, 74AHCT257PW,112 pinout, 74AHCT257PW,112 application, or 74AHCT257PW,112 equivalent, key selection criteria include TTL-level input compatibility, 3-state output enable timing (t_en ≤ 12.0 ns at V_CC = 5.5 V), propagation delay (t_pd ≤ 9.0 ns at CL = 15 pF), and operation across –40 °C to +125 °C.

Technical Context

This device implements four independent 2:1 multiplexers sharing a common select line (S) and a single active-low output enable (OE). Each channel routes either I0 or I1 to its Y output based on S, with outputs entering high-impedance state when OE is HIGH. The non-inverting data path ensures signal polarity preservation across all channels.

All inputs incorporate Schmitt-trigger action, providing hysteresis (typically 0.4 V at V_CC = 5.0 V) to reject noise on select and data lines. Input levels are TTL-compatible (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V), while outputs drive CMOS loads with VOH ≥ 3.70 V and VOL ≤ 0.55 V at IO = ±8.0 mA.

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1); 16 leads; body width 4.4 mm; 0.65 mm lead pitch; exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 2-input multiplexer applications.

Compared with 74AHCT157PW,112, the 74AHCT257PW,112 provides essential bus arbitration via OE and unified control, while SN74LVC157APW trades voltage flexibility for lower latency in 3.3 V-only systems - making the 74AHCT257PW,112 optimal for robust 5 V legacy integration.

Availability

74AHCT257PW,112 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, digital test equipment signal routing, and legacy system bus interface applications requiring stable component supply across extended temperature ranges.

Supply support for 74AHCT257PW,112 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

Nexperia is a leading semiconductor manufacturer specializing in high-performance logic, analog, and discrete components, with core expertise in reliability engineering and automotive-grade qualification.

The 74AHCT series targets industrial and legacy-system designers needing TTL-compatible, high-noise-immunity logic with extended temperature operation and robust ESD/latch-up performance.

FAQ

What is the maximum clock frequency supported by the 74AHCT257PW,112 for reliable data switching?

The device does not operate on a clock; it is combinational logic. Reliable data switching depends on input transition rates and load capacitance. At V_CC = 5.5 V and C_L = 15 pF, propagation delay is ≤ 9.0 ns, supporting data rates up to ~110 MHz in worst-case path timing. Input rise/fall rates must be ≤ 20 ns/V per datasheet Table 5.

Can the 74AHCT257PW,112 interface safely between a 3.3 V microcontroller and a 5 V peripheral?

Yes - its inputs tolerate up to 5.5 V regardless of V_CC, allowing direct connection of 5 V peripheral outputs to any input pin. Outputs swing rail-to-rail (0 V to V_CC), so with V_CC = 3.3 V, they deliver 3.3 V logic levels compatible with most 5 V TTL inputs (VIH ≥ 2.0 V).

Is the 74AHCT257PW,112 pin-compatible with the 74AHC257PW,112?

Yes - both share identical TSSOP16 pinout, pin functions, and package (SOT403-1). The key difference is input threshold: 74AHCT257 accepts TTL levels (VIH ≥ 2.0 V), while 74AHC257 requires CMOS levels (VIH ≥ 3.85 V at V_CC = 5.5 V). Electrical substitution is possible only if driving sources meet the stricter AHC thresholds.

Does the 74AHCT257PW,112 require external pull-up or pull-down resistors on unused inputs?

No - all inputs feature Schmitt-trigger action with defined thresholds and internal biasing. However, OE must be actively driven LOW to enable outputs; leaving OE floating risks undefined output states. Unused data/select inputs may be tied to V_CC or GND per system logic requirements, but external resistors are not required for stability.