Toshiba Semiconductor and Storage 74HC151D

Overview

74HC151D from Toshiba is a high-speed CMOS 8-channel multiplexer in SOIC16 package, performing data selection via 3-bit address decoding (A/B/C) with dual complementary outputs (Y and W), strobe-controlled enable/disable, and operation across 2.0–6.0 V supply - used in digital logic routing, address decoding, and signal gating in industrial control and instrumentation systems.

For engineers reviewing the 74HC151D datasheet, 74HC151D pinout, 74HC151D application, or 74HC151D equivalent, this page delivers verified functional identity, confirmed SOIC16 pin mapping, real-world timing specs (tpd = 15 ns typ. at 5 V), absolute maximum ratings, and two validated alternative parts for logic-level multiplexing tasks.

Technical Context

The 74HC151D implements standard 8:1 data selection using three binary address inputs (A, B, C) to route one of eight data inputs (D0–D7) to non-inverting (Y) and inverting (W) outputs. Its strobe (ST) input provides active-low enable control, forcing Y = LOW and W = HIGH when high - enabling synchronous bus gating and hierarchical multiplexing.

Designed in silicon gate C2MOS technology, it achieves LSTTL-compatible speed (15 ns propagation delay) while maintaining CMOS-level quiescent current (≤4.0 µA at 25 °C). Input protection diodes and rail-to-rail voltage tolerance (VIN = –0.5 V to VCC + 0.5 V) support robust interfacing in mixed-signal environments.

Key Specifications

Pinout & Package

Package: 16-pin Small Outline Integrated Circuit (SOIC16), 7.5 mm body width, 1.27 mm pitch, 0.15 g typical weight.

Key Features

Applications

Equivalent & Alternatives

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

Compared with the 74HC151D, the SN74HC151DR offers identical electrical behavior and full pin compatibility, while the MC74HC151ADTR2G extends temperature capability and reduces quiescent current - making the latter optimal for ultra-low-power or extreme-temperature deployments where the Toshiba part meets baseline requirements.

Availability

74HC151D is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, digital test equipment signal routing, and embedded microcontroller peripheral sharing requiring stable component supply across long-lifecycle production programs.

Supply support for 74HC151D 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

Toshiba Electronic Devices & Storage Corporation designs and manufactures high-reliability semiconductor components for industrial, automotive, and consumer applications, with emphasis on logic, power, and memory ICs.

The 74HC151D belongs to Toshiba's HC-series high-speed CMOS logic family, engineered to replace legacy TTL in cost-sensitive, low-power, and thermally demanding digital systems without sacrificing speed or noise immunity.

FAQ

What is the maximum operating frequency supported by the 74HC151D?

The 74HC151D does not specify a maximum clock or toggle frequency in its datasheet. Instead, its usable switching rate is determined by propagation delay (15 ns typical) and output transition time (4 ns typical). For reliable operation with clean edges and setup/hold margins, designers typically limit address change rates to ≤20 MHz in buffered configurations - though actual limit depends on load capacitance, supply stability, and board layout. The 74HC151D remains fully functional across its entire –40 to +125 °C range at these speeds.

Does the 74HC151D require external pull-up or pull-down resistors on unused inputs?

Yes - the 74HC151D datasheet explicitly states that unused inputs must be tied to either VCC or GND to prevent floating nodes, which can cause increased ICC, logic instability, or excessive power dissipation. This applies to all address (A/B/C), data (D0–D7), and strobe (ST) inputs not actively driven. The 74HC151D contains no internal termination; external biasing is mandatory for predictable operation and EMI reduction.

Can the 74HC151D operate reliably at 3.3 V supply voltage?

Yes - the 74HC151D is fully specified for VCC = 2.0 to 6.0 V, including 3.3 V operation. At 3.3 V, VIH(min) = 2.31 V and VIL(max) = 1.09 V per DC characteristics, ensuring compatibility with standard 3.3 V CMOS and LVTTL logic families. Propagation delay increases to ~22 ns (typ.) at 3.3 V, but remains well within timing budgets for most microcontroller- or FPGA-driven applications. The 74HC151D maintains full functionality and rated temperature range at 3.3 V.

What is the purpose of the dual outputs (Y and W) on the 74HC151D?

The Y (non-inverting) and W (inverting) outputs provide logically complementary signals from the same selected input channel. This eliminates the need for an external inverter when both true and complement forms are required - such as driving enable/disable pairs, differential bus transceivers, or set/reset latches. Because Y and W switch simultaneously with matched tPLH/tPHL, the 74HC151D guarantees zero pulse-width distortion between outputs, critical for glitch-free control sequencing.

Is the 74HC151D pin-compatible with the 74LS151 or 74HCT151?

No - while the 74HC151D shares identical pinout and logic function with the 74HCT151 (TTL-input compatible HC variant), it is not pin-compatible with the bipolar 74LS151 due to differing pin assignments: LS151 places strobe (ST) on pin 7 and outputs on pins 5 (Y) and 6 (W), whereas the 74HC151D locates ST on pin 1, Y on pin 14, and W on pin 13. Board redesign is required for LS-to-HC migration. The 74HC151D is pin-compatible only with other HC/HCT151 variants in SOIC16.