Texas Instruments CD74HCT151MT

Overview

CD74HCT151MT from Texas Instruments is a high-speed CMOS 8-input digital multiplexer with active-low enable (G), three binary select inputs (A/B/C), and complementary non-inverting (Y) and inverting (W) outputs. It operates from 4.5 V to 5.5 V, delivers propagation delays as low as 12 ns (enable-to-Y, 25°C, CL = 50 pF), supports –55°C to +125°C industrial/military temperature range, and provides LSTTL-compatible input thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V). It is used in data routing, address decoding, and logic function generation within embedded control systems.

For engineers reviewing the CD74HCT151MT datasheet, CD74HCT151MT pinout, CD74HCT151MT application, or CD74HCT151MT equivalent, this page delivers verified electrical specs, functional mode truth table alignment, thermal metrics (RθJA = 73°C/W for SOIC), real-world timing constraints under varying load and temperature, and validated drop-in alternatives for legacy board refresh or supply continuity planning.

Technical Context

The CD74HCT151MT implements a single 8:1 multiplexer architecture where three select lines (A, B, C) decode one of eight data inputs (D0–D7) to dual complementary outputs (Y and W), with G enabling or disabling the entire path. Its HCT logic family ensures direct interface with standard TTL outputs while maintaining CMOS power efficiency and noise immunity (NIL/NIH = 30% at VCC = 5 V).

All inputs are buffered, outputs are push-pull, and propagation delay symmetry between Y and W paths is maintained across temperature and voltage. The device exhibits balanced transition times (tt ≤ 22 ns at VCC = 4.5 V) and supports fanout of up to 10 LSTTL loads on standard outputs without external buffering.

Key Specifications

Pinout & Package

CD74HCT151MT is supplied in a 16-pin SOIC (D) package with nominal body size 9.90 mm × 3.90 mm and standard JEDEC MO-012AC footprint. Pin 1 is located in Quadrant Q1 per tape-and-reel orientation standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74HCT151MT, CD74HCT151M96 offers modern packaging logistics and full lifecycle support, while SN74HCT151N provides mechanical and soldering flexibility at the cost of board space - both retain identical timing, voltage, and functional behavior.

Availability

CD74HCT151MT is available at Aetrix Electronics and suitable for industrial control systems, aerospace data acquisition modules, and automotive electronic control units requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD74HCT151MT 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 ICs, with over 90 years of innovation in high-reliability components for mission-critical systems.

The CD74HCT151MT belongs to TI's industry-standard 74HCT logic family, designed specifically for seamless integration between TTL-based legacy systems and modern CMOS-based controllers while maintaining wide temperature operation and low power.

FAQ

What is the maximum operating frequency supported by the CD74HCT151MT?

The CD74HCT151MT does not specify a maximum clock frequency, but its propagation delay (e.g., 12 ns enable-to-Y at 25°C) and transition time (≤22 ns) support reliable operation in data selection circuits up to approximately 20 MHz under typical 50 pF load conditions. System-level timing must account for setup/hold margins relative to control signal edges.

Is the CD74HCT151MT pin-compatible with the CD74HC151 series?

Yes, the CD74HCT151MT shares identical pinout and package (SOIC-16) with CD74HC151 variants, but differs electrically: CD74HCT151MT uses TTL-compatible input thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V), whereas CD74HC151 requires CMOS thresholds (VIL ≤ 1.35 V, VIH ≥ 3.15 V at VCC = 4.5 V). Interchangeability depends on driving source logic family.

Does the CD74HCT151MT require external pull-up or pull-down resistors on unused inputs?

Yes - all unused inputs (A, B, C, D0–D7, G) must be terminated to a defined logic level (VCC or GND) per TI layout guidelines. Floating inputs can cause increased ICC, erratic output behavior, or latch-up due to undefined internal node voltages; tying to VCC or GND ensures predictable functional mode and stable power consumption.

What is the thermal resistance (RθJA) of the CD74HCT151MT in its SOIC package?

The CD74HCT151MT has a junction-to-ambient thermal resistance (RθJA) of 73°C/W in the SOIC (D) package, measured under standard JEDEC JESD51-2 conditions (single-layer board, no copper plane). This value is critical for calculating maximum allowable power dissipation at elevated ambient temperatures.

Can the CD74HCT151MT drive a 50 pF load at 5 V while maintaining specified timing?

Yes - the CD74HCT151MT's switching characteristics (e.g., tpd = 12 ns, tt = 22 ns) are explicitly characterized with CL = 50 pF and VCC = 4.5 V, confirming guaranteed performance under that exact load condition. Output drive capability (±4 mA) ensures adequate slew rate and signal integrity into that capacitance.