onsemi MC74LCX86D

Overview

MC74LCX86D from ON Semiconductor is a low-voltage CMOS quad 2-input XOR gate operating from 2.3 V to 3.6 V supply, featuring 5.5 V-tolerant inputs, 24 mA balanced output drive, near-zero static supply current (10 µA), and TTL/LVCMOS compatibility-used in level-shifting logic interfaces between 3.3 V and 5 V systems.

For engineers reviewing the MC74LCX86D datasheet, pinout, applications, or equivalent options, key selection criteria include input voltage tolerance, propagation delay (≤6.5 ns at 3.3 V), output drive strength, quiescent current, and SOIC-14 package compatibility with legacy 5 V logic interfacing.

Technical Context

The MC74LCX86D implements four independent XOR logic functions in a single monolithic IC, each with symmetrical input thresholds (VIH = 2.0 V, VIL = 0.8 V at VCC ≥ 2.7 V) and rail-to-rail output swing. Its 5.5 V-tolerant inputs enable direct connection to 5 V TTL outputs without external level shifters.

Propagation delays are tightly controlled (tPLH/tPHL ≤ 6.5 ns at VCC = 3.0–3.6 V, CL = 50 pF), and output-to-output skew is guaranteed ≤1.0 ns-critical for synchronous multi-bit parity or error-detection paths where timing alignment across gates matters.

Key Specifications

Pinout & Package

MC74LCX86D is housed in a 14-pin SOIC package (Case 751A), with 1.27 mm pitch, 8.55–8.75 mm body length, and standard JEDEC MS-012 outline. Pin 1 is marked with a beveled corner or dot; pin 7 is GND, pin 14 is VCC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar XOR gate applications.

Compared with SN74LVC86APWR and 74AHC86D, the MC74LCX86D offers superior latchup immunity (>500 mA), lower quiescent current (10 µA), and proven robustness in industrial temperature ranges (−40°C to +85°C), making it preferred for mission-critical interface logic where reliability outweighs marginal speed gains.

Availability

MC74LCX86D is available at Aetrix Electronics and suitable for industrial control interfaces, automotive body electronics, and medical device logic translation requiring stable component supply, long-term lifecycle support, and Pb-free compliance.

Supply support for MC74LCX86D 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

ON Semiconductor (now part of onsemi) is a global semiconductor supplier specializing in energy-efficient power management, analog, logic, and sensing solutions for automotive, industrial, and communications markets.

The MC74LCX86D belongs to the LCX family of low-voltage CMOS logic devices, designed specifically for high-speed, low-power interoperability between 3.3 V and 5 V logic systems in space- and power-constrained applications.

FAQ

What is the maximum input voltage the MC74LCX86D can safely accept?

The MC74LCX86D supports DC input voltages from −0.5 V to +7.0 V, with 5.5 V specified as the absolute maximum safe level for normal operation. This 5 V-tolerant capability allows direct connection to 5 V TTL outputs without external protection circuitry, and is validated across the full operating temperature range (−40°C to +85°C). The MC74LCX86D maintains this rating regardless of VCC level within its 2.3–3.6 V supply range.

Does the MC74LCX86D require external pull-up or pull-down resistors on unused inputs?

No, the MC74LCX86D does not require external pull-up or pull-down resistors on unused inputs because its inputs have high-impedance TTL-compatible structure with defined VIH (2.0 V min) and VIL (0.8 V max) thresholds. However, for predictable logic states and EMI reduction, ON Semiconductor recommends tying unused inputs to VCC or GND. Floating inputs may cause increased ICC or oscillation due to noise coupling, so the MC74LCX86D should never be operated with unterminated inputs in production designs.

What is the typical propagation delay of the MC74LCX86D at 3.3 V supply?

The MC74LCX86D exhibits a maximum propagation delay of 6.5 ns (tPLH/tPHL) at VCC = 3.0–3.6 V with CL = 50 pF and RL = 500 Ω, per the official ON Semiconductor datasheet Rev. 5. Typical values are lower (≈4.5 ns), but design margins must use the guaranteed max. This delay applies uniformly across all four XOR gates, and output-to-output skew is limited to ≤1.0 ns-ensuring timing coherence in parallel logic paths using the MC74LCX86D.

Can the MC74LCX86D drive a 50 Ω transmission line directly?

Yes, the MC74LCX86D can drive a 50 Ω transmission line directly when configured as a source-terminated driver (e.g., series resistor at output), since its output drive strength (24 mA sink/source) supports transient currents needed for 3.3 V logic levels into 50 Ω. However, for clean edge integrity and minimal reflections, a 22–33 Ω series resistor is recommended at the output. The MC74LCX86D's low output capacitance (8 pF typical) and fast edge rates make it suitable for short-run (<10 cm) point-to-point routing without additional buffering.

Is the MC74LCX86D pin-compatible with older 74LS86 or 74HC86 devices?

The MC74LCX86D uses the standard 14-pin SOIC footprint (Case 751A) and matches the pinout of 74LS86 and 74HC86, including identical assignment of GND (pin 7), VCC (pin 14), and all input/output pairs. However, voltage-level compatibility differs: unlike 74LS86 (5 V only) or 74HC86 (2–6 V), the MC74LCX86D operates natively at 2.3–3.6 V with 5 V-tolerant inputs-so while mechanical and logical pinouts align, direct substitution requires verifying supply rail and loading conditions. The MC74LCX86D is not a drop-in replacement without confirming system-level voltage architecture.