STMicroelectronics M74HC151B1R

Overview

M74HC151B1R from STMicroelectronics is a high-speed CMOS 8-channel data multiplexer with pin- and function-compatibility to the 74-series 151. It selects one of eight digital inputs (D0–D7) using three address lines (A, B, C), delivers complementary outputs (Y and W), and features strobe-enabled operation. Key specs include tPD = 17 ns (typ. at VCC = 6 V), VCC range of 2–6 V, IOH/IOL ≥ 4 mA, and ICC ≤ 4 µA (max at TA = 25°C). It is used in logic-level signal routing for industrial control I/O expansion.

For engineers reviewing the M74HC151B1R datasheet, M74HC151B1R pinout, M74HC151B1R application, or M74HC151B1R equivalent, this page provides verified functional identity, validated DIP-16 pin mapping, confirmed propagation delay symmetry (tPLH ≅ tPHL), noise immunity (VNIH/VNIL ≥ 28% VCC), and real-world use cases in combinational logic and address decoding.

Technical Context

The M74HC151B1R implements an 8:1 multiplexer with active-low strobe (STROBE) enabling and complementary outputs (Y and W). Its selection logic follows standard Boolean truth table behavior across A/B/C inputs, with all inputs protected against ESD and transient overvoltage.

It uses silicon gate C2MOS technology to achieve balanced propagation delays (tPLH ≅ tPHL), symmetrical output drive (|IOH| = IOL ≥ 4 mA), and wide supply tolerance (2–6 V). The device operates across –55°C to +125°C and supports logic generation of any four-variable function via external feedback.

Key Specifications

Pinout & Package

Package: Plastic DIP-16 (0.300-inch width), JEDEC MS-001, body dimensions 20.0 × 8.5 mm, lead pitch 2.54 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC151N and 74VHC151N, the M74HC151B1R offers superior extended-temperature support (–55°C to +125°C), lower quiescent current (4 µA vs. 8 µA), and higher noise immunity (28% vs. 20% VCC), making it optimal for ruggedized embedded systems.

Availability

M74HC151B1R is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, legacy system logic emulation, and test equipment signal routing requiring stable component supply and long-term lifecycle assurance.

Supply support for M74HC151B1R 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and logic devices for industrial, automotive, and consumer markets.

The M74HC151B1R belongs to ST's high-speed HC logic family, engineered for pin-compatible upgrades of legacy TTL logic in cost-sensitive, reliability-critical embedded systems.

FAQ

What is the maximum clock/data frequency supported by M74HC151B1R?

The M74HC151B1R is not a clocked sequential device but a combinational multiplexer. Its usable data rate depends on propagation delay and load capacitance. With tPD = 17 ns (typ.) and CL = 50 pF, it reliably handles input transitions up to ~30 MHz in typical configurations. For guaranteed timing, design margins should account for worst-case tPD = 32 ns at VCC = 6 V and TA = 125°C.

Can M74HC151B1R operate with a 3.3 V supply?

Yes. The M74HC151B1R is fully specified for VCC = 2 V to 6 V, including 3.3 V operation. At 3.3 V, VIH = 2.31 V (min), VIL = 1.09 V (max), VOH = 3.23 V (min at IO = –4 mA), and VOL = 0.33 V (max at IO = 4 mA), ensuring interoperability with standard 3.3 V CMOS logic families without level translation.

Is the STROBE pin internally pulled up or down?

No. The STROBE pin has no internal pull-up or pull-down resistor. It is a standard CMOS input requiring explicit biasing. In most applications, STROBE is driven actively by a controller GPIO or tied LOW via a pull-down resistor (e.g., 10 kΩ) to keep the device continuously enabled. Floating STROBE may cause undefined output states.

Does M74HC151B1R support hot insertion or live swapping?

No. The M74HC151B1R lacks hot-swap protection circuitry such as power-on reset, I/O clamp diodes rated for back-drive, or slew-rate controlled inputs. Applying VCC while inputs are asserted, or inserting/removing the device while powered, risks latch-up or permanent damage due to uncontrolled current paths through input protection structures.