STMicroelectronics M74HC151TTR

Overview

M74HC151TTR from STMicroelectronics is a high-speed CMOS 8-channel data multiplexer with complementary Y/W outputs, 3-bit address decoding (A/B/C), active-low strobe enable, and symmetrical 4mA drive capability. It operates from 2V to 6V, delivers 17ns typical propagation delay at 6V, and supports logic function generation for up to four variables in industrial control and digital instrumentation systems.

For engineers reviewing the M74HC151TTR datasheet, M74HC151TTR pinout, M74HC151TTR application, or M74HC151TTR equivalent, key selection criteria include its TSSOP-16 package, 2–6V wide supply range, guaranteed 4mA output drive, -55°C to +125°C operating temperature, and strict pin/function compatibility with standard 74-series 151 logic.

Technical Context

The M74HC151TTR implements an 8:1 multiplexing function using silicon gate C2MOS technology, with three select inputs (A, B, C) determining which of eight data inputs (D0–D7) routes to the true (Y) and complementary (W) outputs. Strobe (pin 7) must be low for normal operation; when high, W is forced high and Y low - enabling cascading or gating control.

Its balanced tPLH/tPHL delays ensure minimal duty-cycle distortion on Y/W outputs, while high noise immunity (VIH/VIL = 28% VCC min) and 4µA max ICC at 25°C support low-power, noise-resilient digital interfacing in mixed-signal environments.

Key Specifications

Pinout & Package

TSSOP-16 package: 4.9 × 6.4 mm body, 0.65 mm pitch, thin-profile surface-mount design compatible with fine-pitch PCB assembly and automated reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC151PWR and 74VHC151FT, the M74HC151TTR offers the broadest temperature range (-55°C to +125°C), identical pinout to legacy 74LS151, and optimal balance of speed, power, and ruggedness for embedded control applications requiring long-term reliability.

Availability

M74HC151TTR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, digital test equipment signal routing, and legacy system logic emulation requiring stable component supply and long-lifecycle support.

Supply support for M74HC151TTR 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 analog/mixed-signal devices for industrial, automotive, and consumer markets.

The M74HC151TTR belongs to ST's high-speed CMOS logic family, engineered for pin-compatible upgrades of legacy TTL designs while delivering lower power, wider voltage operation, and enhanced noise immunity in space-constrained embedded systems.

FAQ

What is the maximum clock frequency supported by M74HC151TTR for reliable data selection?

The M74HC151TTR does not operate on a clock; it is asynchronous. Its 17ns typical propagation delay at 6V implies reliable operation with input address changes up to ~30 MHz in worst-case timing paths. For deterministic operation, ensure address and strobe setup/hold times exceed 5ns per AC specs, and avoid violating minimum pulse width (20ns) on strobe transitions.

Can M74HC151TTR drive a 50Ω transmission line directly?

No - its 4mA output drive is insufficient for clean 50Ω termination. At 5V, 4mA yields only 200mV across 50Ω, far below logic thresholds. Use a dedicated line driver (e.g., 74LVC244) or series-terminate with 33Ω resistor to match 50Ω impedance while preserving logic levels.

Does M74HC151TTR support hot insertion or live insertion into powered systems?

No - it lacks hot-swap protection circuitry. Applying VCC before GND, or connecting inputs before supply stabilization, may cause latch-up or ESD damage. Always follow proper power sequencing: GND first, then VCC, then inputs. Use series resistors (100Ω) on all inputs if hot-plug risk exists.

How does the strobe input interact with address changes during selection?

When STROBE is low, Y/W reflect the currently selected Dn based on A/B/C. If A/B/C change while STROBE remains low, Y/W update after tPD (e.g., 22ns max at 4.5V). If STROBE goes high mid-transition, Y immediately goes low and W high - overriding any partial switching, ensuring glitch-free disable.