Texas Instruments SN74HC151D

Overview

SN74HC151D 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 supply, with typical propagation delay of 43 ns at 6 V and ±6-mA output drive capability. It performs Boolean-function generation and parallel-to-serial conversion in digital logic systems requiring precise signal routing.

For engineers reviewing the SN74HC151D datasheet, SN74HC151D pinout, SN74HC151D application, or SN74HC151D equivalent, this page delivers verified functional modes, switching characteristics, input/output voltage thresholds, thermal resistance (73°C/W), and real-world use cases for industrial control, test equipment, and address decoding circuits.

Technical Context

The SN74HC151D implements full binary decoding across three select inputs (A, B, C) to route one of eight data inputs (D0–D7) to the standard (Y) and inverted (W) outputs. Strobe (G) enables or disables all outputs: low G enables selection; high G forces Y = LOW and W = HIGH regardless of select state.

It operates in standard CMOS logic family with rail-to-rail input compatibility, 1 μA max input current, and 80 μA max ICC. Output drive supports up to 10 LSTTL loads, and switching performance is characterized at CL = 50 pF and CL = 150 pF across 2 V, 4.5 V, and 6 V supply conditions.

Key Specifications

Pinout & Package

SN74HC151D is housed in a 16-pin SOIC (Small Outline Integrated Circuit) package measuring 9.90 mm × 3.90 mm, with 1.27 mm lead pitch and gull-wing surface-mount terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC151D, SN74HCT151D offers guaranteed TTL input compatibility at the cost of marginally higher static current, while CD74HC151M provides identical HC-family performance with alternate logistics traceability-both require no PCB changes and support drop-in replacement in existing SOIC-16 footprints.

Availability

SN74HC151D is available at Aetrix Electronics and suitable for industrial control logic, test equipment signal routing, microcontroller address decoding, and Boolean function generation requiring stable component supply across extended production lifecycles.

Supply support for SN74HC151D 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 global semiconductor leader specializing in analog, embedded processing, and logic solutions, with over 50 years of innovation in high-reliability digital ICs.

The SN74HC151D belongs to TI's 74HC logic family, designed for low-power, high-speed CMOS applications in industrial, automotive, and communications systems where noise immunity and wide supply tolerance are critical.

FAQ

What is the maximum propagation delay of the SN74HC151D at 5 V supply?

The maximum propagation delay (tpd) of the SN74HC151D is 63 ns at VCC = 4.5 V and CL = 50 pF, measured from any select input (A/B/C) to Y or W output. At exactly 5 V, interpolation from datasheet curves confirms tpd remains within this 63 ns bound, supporting reliable operation in 12-MHz synchronous logic designs. This value is validated across –40°C to +85°C.

Does the SN74HC151D support 3.3 V logic systems?

Yes, the SN74HC151D fully supports 3.3 V operation: its recommended supply range (2 V to 6 V) includes 3.3 V, and input thresholds scale proportionally (VIH ≥ 2.31 V, VIL ≤ 0.99 V at 3.3 V). Output VOH/VOL meet 3.3 V LVTTL requirements, enabling direct interface with FPGA I/O banks and ARM-based microcontrollers without level shifting.

How does the strobe (G) input affect output states in the SN74HC151D?

When G is HIGH, the SN74HC151D forces Y = LOW and W = HIGH regardless of A/B/C or D-input states-effectively disabling data routing. When G is LOW, the device performs normal 8-to-1 selection: Y mirrors the selected D-input, and W provides its logical inverse. This enables hierarchical multiplexing and enables cascading with other SN74HC151D units.

Can unused inputs on the SN74HC151D be left floating?

No-unused inputs on the SN74HC151D must be tied to VCC or GND. Floating CMOS inputs cause undefined internal node voltages, leading to increased ICC, oscillation, or excessive power dissipation. TI explicitly mandates this in Section 5.2 of the datasheet; for example, unneeded D-inputs should be pulled to GND to prevent leakage-induced state instability.

What is the thermal resistance (θJA) of the SN74HC151D in its SOIC package?

The junction-to-ambient thermal resistance (θJA) of the SN74HC151D in the SOIC-16 (D) package is 73°C/W under standard JEDEC JESD51-2 board conditions. This value assumes a two-layer board with 1 in² copper pour under the package; actual θJA may improve with enhanced PCB copper area or airflow, but derating is required above 70°C ambient for sustained 80 μA ICC operation.