Nexperia USA Inc. 74HC251DB,112

Overview

74HC251DB,112 from Nexperia is an 8-input CMOS multiplexer with complementary outputs (Y and Y), three binary select lines (S0–S2), and active-low 3-state output enable (OE). It operates from 2.0 V to 6.0 V, delivers propagation delay as low as 14 ns at 6.0 V, supports industrial temperature range (−40 °C to +125 °C), and is used in digital logic routing, data selector circuits, and address decoding in microcontroller peripheral interfaces.

For engineers reviewing the 74HC251DB,112 datasheet, 74HC251DB,112 pinout, 74HC251DB,112 application, or 74HC251DB,112 equivalent, key selection considerations include supply voltage compatibility (2.0–6.0 V), TTL/CMOS input level distinction (HC vs HCT), 3-state output timing (enable/disable times down to 10 ns), and SO16 package thermal derating above 110 °C.

Technical Context

The 74HC251DB,112 implements a non-inverting 8:1 data path with fully buffered select inputs and independent high-impedance control via OE. Its internal architecture uses standard CMOS transmission gates and inverters to route one of eight inputs to dual complementary outputs without inversion.

It features input clamp diodes for overvoltage tolerance, JESD78 Class II Level B latch-up immunity (>100 mA), and ESD protection meeting HBM >2000 V and CDM >1000 V. The device is specified across −40 °C to +125 °C and complies with JEDEC JESD8C and JESD7A standards.

Key Specifications

Pinout & Package

74HC251DB,112 is supplied in SO16 (SOT109-1) plastic small outline package: 16-pin, 3.9 mm body width, 1.27 mm lead pitch, gull-wing leads. Thermal resistance θJA = 80 K/W (SO16); total power dissipation derates linearly at 12.4 mW/K above 110 °C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-input multiplexer applications.

Compared with 74HCT251DB,112, the HC variant gives superior noise immunity in mixed-signal systems but requires CMOS-level drivers; versus SN74HC251N, the SO16 package enables higher density layout and better thermal management in automated assembly.

Availability

74HC251DB,112 is available at Aetrix Electronics and suitable for industrial automation, test equipment, and embedded control applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for 74HC251DB,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 global semiconductor expert delivering high-performance, reliable logic, analog, and MOSFET solutions with focus on efficiency, reliability, and sustainability.

The 74HC251DB,112 belongs to Nexperia's 74HC logic family - engineered for low-power, high-noise-immunity digital signal routing in industrial, consumer, and communications equipment.

FAQ

Can 74HC251DB,112 operate reliably at 3.3 V?

Yes. The 74HC251DB,112 is fully specified from 2.0 V to 6.0 V. At 3.3 V, VIH = 2.31 V (min), VIL = 1.09 V (max), propagation delay is 22 ns (typ), and output drive is ±4 mA - meeting requirements for 3.3 V LVTTL and most microcontroller GPIOs without level shifting.

What is the maximum capacitive load it can drive while maintaining timing specs?

The datasheet specifies dynamic characteristics at CL = 50 pF. For guaranteed tpd ≤ 34 ns (VCC = 4.5 V), load capacitance must not exceed 50 pF. With heavier loads (e.g., 100 pF), propagation delay increases to ~55 ns, and transition time degrades - verify timing margins in final layout with IBIS simulation.

Is the Y output truly complementary to Y, or is it just an inverted copy?

Y is the true logical complement of Y: when Ix = HIGH, Y = HIGH and Y = LOW; when Ix = LOW, Y = LOW and Y = HIGH. Both outputs are simultaneously enabled or disabled by OE. This dual-output structure supports differential signaling, wired-OR logic, or redundancy checking in safety-critical paths.

Does OE require a pull-up resistor in systems where it's controlled by an open-drain MCU pin?

No. OE is a CMOS input with leakage current <±0.1 μA at 6 V. An open-drain MCU pin can directly drive OE LOW (to enable) and release it (to float HIGH), provided the MCU's internal weak pull-up or board-level pull-up ensures OE ≥ 0.7×VCC when released. A 10 kΩ external pull-up to VCC is recommended for deterministic startup behavior.