Nexperia USA Inc. 74HCT251D,653

Overview

74HCT251D,653 from Nexperia is an 8-input TTL-compatible CMOS multiplexer with complementary outputs (Y and Y), 3-state output enable (active LOW), and operation across 4.5 V to 5.5 V supply. It selects one of eight data inputs (I0–I7) using three binary select lines (S0–S2) and supports industrial temperature range (−40 °C to +125 °C). Used in digital logic routing, address decoding, and bus arbitration circuits.

For engineers reviewing the 74HCT251D,653 datasheet, 74HCT251D,653 pinout, 74HCT251D,653 application, or 74HCT251D,653 equivalent, key selection criteria include TTL-level input compatibility, propagation delay under 35 ns at 5 V, 3-state output control timing, and SO16 package thermal derating above 110 °C.

Technical Context

The 74HCT251D,653 implements a single 8:1 multiplexer with non-inverting data path and dual complementary outputs. Its TTL-compatible inputs accept 2.0 V minimum HIGH and 0.8 V maximum LOW thresholds at VCC = 5 V, enabling direct interfacing with legacy 5 V TTL logic families without level shifters.

Output enable (OE) controls high-impedance state on both Y and Y simultaneously, with enable/disable times ≤42 ns at 5 V and CL = 50 pF. Propagation delay from data input to Y/Y is ≤53 ns over full temperature range, and transition time is ≤22 ns, supporting reliable operation in synchronous digital systems up to ~10 MHz.

Key Specifications

Pinout & Package

74HCT251D,653 is housed in a plastic small outline package (SO16), SOT109-1, with 16 leads and 3.9 mm body width. Thermal derating begins at 110 °C (12.4 mW/K).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8:1 multiplexer applications.

Compared with SN74HCT251N, 74HCT251D,653 offers superior thermal performance and SMT manufacturability; compared with 74LVX251M, it provides native 5 V TTL interoperability but consumes slightly more dynamic power at equivalent frequencies.

Availability

74HCT251D,653 is available at Aetrix Electronics and suitable for industrial automation, automotive diagnostics, and embedded instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HCT251D,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 delivering high-performance, reliable logic, discrete, and MOSFET solutions with focus on efficiency, reliability, and sustainability.

The 74HCT series targets industrial and automotive applications requiring TTL-compatible CMOS logic with robust ESD, latch-up, and thermal performance - specifically engineered for mixed-signal system integration and legacy interface bridging.

FAQ

What is the maximum clock frequency supported by the 74HCT251D,653?

The 74HCT251D,653 does not operate on a clock; it is combinational logic. Its usable data rate depends on propagation delay (≤53 ns) and system setup/hold timing. For reliable operation with 50 pF load, maximum toggle rate is ~10 MHz, assuming ≥10 ns minimum pulse width and clean edge transitions.

Can the Y and Y outputs drive separate loads independently?

No - Y and Y are complementary outputs derived from the same internal node and share identical 3-state control via OE. Both outputs enter high-impedance simultaneously when OE is HIGH; neither can be individually disabled or inverted relative to the other.

Is the 74HCT251D,653 pin-compatible with the 74HC251D variant?

Yes - both share identical SO16 pinout (SOT109-1), pin functions, and package dimensions. The only functional difference is input threshold levels: 74HCT251D accepts TTL inputs, while 74HC251D requires CMOS-level inputs (VIH ≥ 3.15 V at 4.5 V).

Does the device require external pull-up or pull-down resistors on unused inputs?

Unused select (S0–S2) or data (I0–I7) inputs must be tied to VCC or GND. Floating inputs risk increased ICC, noise susceptibility, and undefined output states. OE should be pulled LOW (via resistor or direct connection) if permanently enabled, or driven actively for 3-state control.