STMicroelectronics M74HC251RM13TR

Overview

M74HC251RM13TR from STMicroelectronics is a high-speed CMOS 8-channel 3-state multiplexer with true (Y) and complementary (W) outputs, STROBE-controlled output enable, and symmetrical 4 mA drive capability at VCC = 6 V. It operates across 2–6 V, delivers 17 ns typical propagation delay at 6 V, and supports industrial temperature range (−55 °C to +125 °C). Used in digital data routing, address decoding, and bus multiplexing in embedded control systems.

For engineers reviewing the M74HC251RM13TR datasheet, M74HC251RM13TR pinout, M74HC251RM13TR application, or M74HC251RM13TR equivalent, key selection criteria include 3-state output timing (tPZL/tPLZ), input noise immunity (28 % VCC), supply current (4 µA max at 25 °C), and TSSOP-16 package compatibility with high-density PCB layouts.

Technical Context

The M74HC251RM13TR implements an 8:1 data selector using silicon gate C2MOS technology, with independent A/B/C address decoding and STROBE-gated 3-state output control. Its dual Y/W outputs provide simultaneous true and inverted logic paths without external inversion.

It features balanced tPLH ≅ tPHL propagation delays, high noise immunity (VIH/VIL thresholds fixed at 3.15 V / 1.35 V at VCC = 4.5 V), and robust ESD protection on all inputs. The device maintains stable operation under fast input transitions (tr/tf ≤ 400 ns at VCC = 6 V).

Key Specifications

Pinout & Package

TSSOP-16 package: 4.9 × 6.4 mm body, 0.65 mm pitch, thin-profile surface-mount design optimized for automated assembly and thermal performance in space-constrained applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-channel 3-state multiplexer applications.

Compared with SN74HC251PWR and 74VHC251MTCX, the M74HC251RM13TR offers superior noise immunity, wider temperature range, and lower quiescent current-making it optimal for high-reliability embedded systems where signal integrity and long-term stability are critical.

Availability

M74HC251RM13TR is available at Aetrix Electronics and suitable for industrial PLC I/O consolidation, automotive body control modules, test equipment signal routing, and medical patient monitor front-ends requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for M74HC251RM13TR 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, specializing in automotive, industrial, and power management ICs with vertical manufacturing and AEC-Q100 qualification capabilities.

The M74HC251 belongs to ST's high-speed HC logic family, designed specifically for low-power, noise-immune digital interfacing in harsh-environment control systems where reliability and timing predictability are non-negotiable.

FAQ

Can M74HC251RM13TR operate reliably at 2.0 V supply?

Yes. Per ST's recommended operating conditions, the device is fully specified down to VCC = 2.0 V with guaranteed VIH = 1.5 V, VOL ≤ 0.1 V at 20 µA, and tPD ≤ 195 ns. It maintains functional operation and noise margin at this voltage, making it suitable for coin-cell or energy-harvesting applications where supply headroom is minimal.

What is the maximum input transition rate supported?

The datasheet specifies maximum input rise/fall times of 400 ns at VCC = 6.0 V, corresponding to a minimum allowable transition rate of 2.5 MHz. Faster edges may cause increased dynamic current or metastability in address decoding; for >10 MHz switching, external Schmitt-trigger conditioning is recommended per ST AN2217 guidelines.

Does ST provide SPICE models for M74HC251RM13TR?

ST does not publish a dedicated SPICE model for the M74HC251RM13TR. However, its behavior can be accurately simulated using the generic 74HCxx library models in LTspice or PSpice, with validated parameters including CPD = 62 pF, input capacitance = 5–10 pF, and output drive strength matched to ±4 mA at VCC = 6 V.

How is the STROBE pin used in bus-sharing configurations?

In bus-sharing, STROBE is driven low only during valid data windows and held high otherwise. This forces Y/W into high-impedance, preventing contention when other devices drive the same bus line. Timing must ensure tPZH (max 23 ns at 6 V) elapses before releasing bus control to avoid glitches during state transitions.