Texas Instruments SN74HC151DT

Overview

SN74HC151DT 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 <100 nA input leakage. It enables binary-decoded selection of one of eight digital inputs for logic-level routing in bus management and Boolean function generation.

For engineers reviewing the SN74HC151DT datasheet, SN74HC151DT pinout, SN74HC151DT application, or SN74HC151DT equivalent, this page provides verified functional mode behavior, validated switching characteristics at 50 pF load, confirmed strobe-controlled enable logic, and real-world design implications of its dual Y/W outputs and low-power operation.

Technical Context

The SN74HC151DT implements full binary decoding across three select lines (A, B, C) to route one of eight data inputs (D0–D7) to the non-inverted output (Y) and inverted output (W). Its strobe (G) input forces both outputs to fixed logic states (Y = L, W = H) when high, enabling synchronous gating in time-critical control paths.

It operates within −40°C to +85°C ambient temperature, supports 50 pF capacitive loading per output, and exhibits asymmetric propagation delays: 25 ns (min) / 43 ns (max) from select inputs to Y/W at 6 V, and 20 ns (min) / 33 ns (max) from any D input to Y/W under identical conditions.

Key Specifications

Pinout & Package

SN74HC151DT uses a 16-pin SOIC (D) package measuring 9.90 mm × 3.90 mm with standard 1.27 mm pitch. Pin 1 is located at the top-left corner adjacent to the index notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC151N and SN74HC251DR, the SN74HC151DT offers optimized surface-mount manufacturability in SOIC-16 while retaining identical core logic, timing, and drive strength-making it ideal for high-volume industrial PCBs where footprint and thermal profile matter.

Availability

SN74HC151DT is available at Aetrix Electronics and suitable for industrial control logic, test equipment signal routing, embedded system bus management, and Boolean function generation requiring stable component supply and long-term lifecycle support.

Supply support for SN74HC151DT 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 SN74HC151DT belongs to TI's 74HC logic family, designed for low-power, high-noise-immunity digital interfacing in industrial, instrumentation, and automotive-qualified systems.

FAQ

What is the function of the strobe (G) input on the SN74HC151DT?

The strobe (G) input on the SN74HC151DT is an active-low enable signal. When G is high, the standard output (Y) is forced low and the inverted output (W) is forced high, overriding all select and data inputs. When G is low, the device operates normally, routing the selected Dn input to Y and its complement to W. This behavior is explicitly defined in the function table and timing diagrams of the official SN74HC151 datasheet.

Does the SN74HC151DT support 3.3 V operation?

Yes, the SN74HC151DT supports 3.3 V operation within its specified 2 V to 6 V supply range. At VCC = 3.3 V, input thresholds are VIH ≥ 2.31 V and VIL ≤ 0.99 V, providing adequate noise margin for standard 3.3 V CMOS logic. Electrical characteristics including propagation delay and output drive are guaranteed across this entire voltage range per TI's recommended operating conditions.

What is the maximum capacitive load the SN74HC151DT can drive reliably?

The SN74HC151DT is characterized for reliable operation with up to 50 pF capacitive load per output, as confirmed in Section 5.5 (Switching Characteristics) of the datasheet. At VCC = 5 V and TA = 25°C, tpd remains within 39 ns (typical) to 63 ns (max) under this load. Driving >50 pF may increase propagation delay nonlinearly and is not guaranteed without empirical validation.

Can unused inputs on the SN74HC151DT be left floating?

No, unused inputs on the SN74HC151DT must never be left floating. TI explicitly states in Section 5.2 and Layout Guidelines that all unused inputs must be tied to VCC or GND to prevent undefined logic states, increased ICC, or oscillation. Floating CMOS inputs cause unpredictable current draw and potential device malfunction due to intermediate voltage levels triggering both NMOS and PMOS transistors.

Is the SN74HC151DT pin-compatible with other 74HC-series multiplexers like the SN74HC251?

No, the SN74HC151DT is not pin-compatible with the SN74HC251. While both are 8-to-1 multiplexers in SOIC-16 packages, their pin assignments differ: SN74HC151DT places strobe (G) on Pin 1 and outputs Y/W on Pins 14/13, whereas SN74HC251 assigns strobe to Pin 13 and uses different select line ordering. Direct substitution would require PCB layout changes and firmware logic adaptation.