Nexperia USA Inc. 74HCT257D,653

Overview

74HCT257D,653 from Nexperia is a quad 2-input multiplexer with 3-state outputs, designed for bus-oriented data routing in TTL-level logic systems. It operates from 4.5 V to 5.5 V, delivers propagation delay as low as 13 ns at 4.5 V (CL = 15 pF), supports -40 °C to +125 °C operation, and features TTL-compatible inputs enabling direct interfacing with legacy microcontrollers and peripheral controllers.

For engineers reviewing the 74HCT257D,653 datasheet, 74HCT257D,653 pinout, 74HCT257D,653 application, or 74HCT257D,653 equivalent, key selection criteria include its 3-state bus interface capability, guaranteed TTL input thresholds (VIH ≥ 2.0 V, VIL ≤ 0.8 V), SO16 package thermal performance (Ptot = 500 mW @ Tj ≤ 110 °C), and enable-controlled output isolation timing (ten/tdis ≤ 30 ns at 4.5 V).

Technical Context

The 74HCT257D,653 implements four independent 2:1 multiplexers sharing a common select line (S) and a single active-low 3-state output enable (OE). Each multiplexer routes either I0 or I1 to its Y output based on S, while OE controls high-impedance state across all four outputs simultaneously - enabling direct connection to shared data buses without external gating.

Its TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 4.5–5.5 V) ensure robust noise margin when driven by standard 5 V TTL sources, and its CMOS output structure provides rail-to-rail VOH/VOL (VOH ≥ 3.98 V, VOL ≤ 0.26 V at IO = ±6 mA), supporting mixed-logic system interfacing.

Key Specifications

Pinout & Package

74HCT257D,653 is housed in a plastic small outline package (SO16, SOT109-1) with 16 leads and 3.9 mm body width, optimized for surface-mount assembly and thermal reliability in industrial environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HCT257N and 74LVC257PW, the 74HCT257D,653 uniquely balances 5 V TTL compatibility, SO16 manufacturability, and industrial temperature resilience - making it the optimal choice for volume-produced industrial controllers requiring drop-in replacement of legacy 74-series logic.

Availability

74HCT257D,653 is available at Aetrix Electronics and suitable for industrial automation, test instrumentation, and embedded control systems requiring stable component supply across long product lifecycles.

Supply support for 74HCT257D,653 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 global semiconductor expert focused on high-volume, high-reliability logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74HCT series is engineered for seamless integration into 5 V TTL-based digital systems, emphasizing robust noise immunity, wide operating margins, and long-term supply stability for industrial-grade designs.

FAQ

Can 74HCT257D,653 operate reliably at 4.2 V supply?

No - the 74HCT257D,653 is specified only for 4.5 V to 5.5 V operation per JEDEC JESD7A. At 4.2 V, VIH minimum drops below guaranteed TTL threshold (2.0 V), risking input recognition failure. Operation outside recommended conditions voids parametric guarantees and may cause metastability or increased ICC.

What is the maximum capacitive load each Y output can drive while maintaining 13 ns propagation delay?

The 13 ns typical tpd is measured with CL = 15 pF. Driving >20 pF increases tpd nonlinearly due to RC delay; at 50 pF, tpd degrades to ~30 ns. For consistent timing, limit total load (including trace and receiver input capacitance) to ≤15 pF per output, or add series termination if driving longer traces.

Does the 74HCT257D,653 support hot insertion into a live 5 V bus?

No - the device lacks hot-swap protection circuitry. Applying VCC before GND, or connecting OE/Y pins while unpowered, risks latch-up or ESD damage. Always power GND first, then VCC, and assert OE HIGH before enabling signal connections. Use external series resistors (22–47 Ω) on Y lines for in-system programming scenarios.

How does the 3-state output behavior change when OE is left floating?

OE has no internal pull-up/down; a floating OE defaults to undefined logic level, causing unpredictable output states. This may result in partial bus contention or excessive ICC. Always tie OE to a defined logic level - typically pulled HIGH via 10 kΩ resistor to VCC when permanently disabling outputs, or actively driven by controller GPIO.