Texas Instruments SN74HC151DE4

Overview

SN74HC151DE4 from Texas Instruments is an 8-line to 1-line CMOS data selector/multiplexer in SOIC-16 package, operating from 2 V to 6 V, delivering 13 ns typical propagation delay at 5 V, ±6 mA output drive, and <80 μA max supply current - used for Boolean-function generation, parallel-to-serial conversion, and data source selection in digital logic systems.

For engineers reviewing the SN74HC151DE4 datasheet, SN74HC151DE4 pinout, SN74HC151DE4 application, or SN74HC151DE4 equivalent, this page provides verified functional modes, validated timing characteristics, confirmed package dimensions (9.90 mm × 3.90 mm), and real-world multiplexer use cases in industrial control and embedded signal routing.

Technical Context

The SN74HC151DE4 implements full binary decoding across three select inputs (A, B, C) to route one of eight data inputs (D0–D7) to the non-inverted output (Y) and inverted output (W). Strobe input (G) enables or disables all outputs: low G enables selection; high G forces Y = LOW and W = HIGH.

It operates as a standard HC-series CMOS device with rail-to-rail input thresholds (VIH = 3.15 V, VIL = 1.35 V at VCC = 4.5 V), supports 10 LSTTL loads, and features low input current (≤1 μA) and low power dissipation (Cpd = 70 pF).

Key Specifications

Pinout & Package

SN74HC151DE4 uses a 16-pin SOIC (D) package with nominal body size 9.90 mm × 3.90 mm and 1.27 mm lead pitch. Pin numbering follows JEDEC MS-012, with Pin 1 in top-left corner (index area marked).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC251N and CD74HC151E, the SN74HC151DE4 provides fixed-output behavior ideal for static routing, avoids tri-state contention risks, and maintains lowest gate count in non-bus applications - making it optimal for dedicated selector roles where output enable is unnecessary.

Availability

SN74HC151DE4 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, digital test equipment signal routing, embedded microcontroller peripheral sharing, and legacy bus interface logic requiring stable component supply and long-term manufacturability.

Supply support for SN74HC151DE4 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

Texas Instruments is a U.S.-based semiconductor company founded in 1930, specializing in analog and embedded processing technologies with broad portfolio coverage and global manufacturing scale.

The SN74HC151DE4 belongs to TI's 74HC logic family - designed for high-speed, low-power CMOS digital signal routing in commercial and industrial systems where reliability, consistency, and wide VCC tolerance are essential.

FAQ

What is the function of the strobe (G) input on the SN74HC151DE4?

The strobe (G) input on the SN74HC151DE4 is an active-low enable signal. When G is LOW, the device performs normal 8:1 multiplexing based on select inputs A, B, and C. When G is HIGH, the standard output Y is forced LOW and the inverted output W is forced HIGH - overriding all data and select inputs. This allows global disable without changing address lines.

Can the SN74HC151DE4 operate reliably at 3.3 V supply voltage?

Yes, the SN74HC151DE4 operates reliably across 2 V to 6 V, including 3.3 V. At VCC = 3.3 V, VIH is guaranteed ≥ 2.31 V and VIL ≤ 0.99 V, providing >1.3 V noise margin. Propagation delay increases to ~19 ns (typ), and output drive reduces to ±4.2 mA - still sufficient for driving 74LVC or modern MCU inputs.

Does the SN74HC151DE4 require external pull-up or pull-down resistors on unused select inputs?

Yes - all unused select inputs (A, B, C) and the strobe (G) must be tied to either VCC or GND. Floating CMOS inputs cause undefined output states and increased ICC due to shoot-through current. TI recommends using 10 kΩ resistors for robust biasing; direct connection is acceptable if board layout ensures no noise coupling.

How does the SN74HC151DE4 differ from the SN74HC251 in practical design?

The SN74HC151DE4 has fixed-output behavior (Y and W always driven), while the SN74HC251 adds tri-state capability on both outputs via an active-low output-enable (OE̅) pin. This makes SN74HC251 suitable for shared buses, but introduces additional control logic and potential contention risk if OE̅ is mismanaged - SN74HC151DE4 avoids those complexities in point-to-point routing.

Is the SN74HC151DE4 pin-compatible with older 74LS151 devices?

No - SN74HC151DE4 is not pin-compatible with 74LS151. While both are 8:1 multiplexers in 16-pin packages, LS151 uses different pin assignments (e.g., LS151 places VCC at Pin 16 but GND at Pin 8, whereas HC151 swaps GND/Pin 8 and VCC/Pin 16). Interchange requires PCB redesign; electrical differences (TTL vs. CMOS thresholds, drive strength) also preclude direct substitution.