onsemi 74LCX02M

Overview

74LCX02M from onsemi is a low-voltage quad 2-input NOR gate IC with 5 V tolerant inputs, designed for level-shifting between 3 V and 5 V logic systems. It operates across 1.65 V–5.5 V V_CC, delivers ≤5.2 ns propagation delay at 3.3 V, supports ±24 mA output drive, and features power-down high-impedance I/O for bus-hold compatibility in mixed-voltage embedded control interfaces.

For engineers reviewing the 74LCX02M datasheet, pinout, applications, or equivalent options, this page provides verified functional identity, TSSOP-14 package mapping, AC/DC electrical specifications per JEDEC conditions, and validated alternatives for voltage translation and noise-sensitive logic interfacing.

Technical Context

The 74LCX02M implements four independent 2-input NOR gates using advanced CMOS process technology to achieve high-speed operation (≤5.2 ns t_PLH/t_PHL at V_CC = 3.3 V) while maintaining sub-10 µA quiescent current. Its input structure tolerates up to 5.5 V regardless of V_CC, enabling direct connection to legacy 5 V buses without external level shifters.

Each gate exhibits rail-to-rail output swing, ±24 mA drive capability at 3.0 V, and proprietary noise/EMI reduction circuitry. Power-down mode places both inputs and outputs in high-impedance state when V_CC = 0 V, supporting hot-swap and partial-power-down system architectures.

Key Specifications

Pinout & Package

TSSOP-14 wide-body package (Case 948G), 5.0 mm × 4.4 mm footprint, 0.65 mm pitch, Pb-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NOR gate logic applications.

Compared with SN74LVC02APWR and 74AHC02PW,118, the 74LCX02M uniquely supports true 5 V-tolerant inputs at V_CC as low as 1.65 V-enabling direct interconnection between legacy 5 V subsystems and modern low-voltage controllers without redesigning signal conditioning networks.

Availability

74LCX02M is available at Aetrix Electronics and suitable for industrial sensor interface, automotive body control, programmable logic controller I/O expansion, and medical diagnostic equipment requiring stable component supply across extended temperature and mixed-voltage operating conditions.

Supply support for 74LCX02M 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

onsemi is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The 74LCX02M belongs to the LCX family of low-voltage, high-speed CMOS logic devices engineered specifically for mixed-voltage system interfacing and noise-critical digital signal routing in harsh environments.

FAQ

What is the maximum input voltage the 74LCX02M can tolerate when V_CC = 1.8 V?

The 74LCX02M supports DC input voltages up to 5.5 V regardless of V_CC level, including at 1.8 V operation. This 5 V tolerance is explicitly specified in the Absolute Maximum Ratings table and confirmed in the General Description section of the onsemi datasheet. The 74LCX02M achieves this via internal input protection structures that isolate the core logic from overvoltage stress, making it ideal for interfacing 5 V sensors or microcontrollers to low-voltage hosts.

Does the 74LCX02M support hot-swap or partial power-down operation?

Yes, the 74LCX02M enters a high-impedance state on both inputs and outputs when V_CC = 0 V, as documented in the Features list and DC Electrical Characteristics table (IOFF ≤ 10 µA). This power-down behavior prevents back-driving of powered sections and eliminates bus contention during live insertion or staged power sequencing-critical for modular PLCs and field-replaceable computing blades where the 74LCX02M serves as domain-isolation logic.

What is the typical propagation delay of the 74LCX02M at 2.5 V supply?

While the datasheet specifies maximum propagation delay (t_PLH/t_PHL) of 6.2 ns at V_CC = 2.3–2.7 V, it does not provide a typical value at 2.5 V. The 5.2 ns max at 3.3 V and 6.2 ns max at 2.5 V reflect worst-case performance across temperature and process corners. For design timing margins, engineers should use the 6.2 ns max value at 2.5 V; actual typical delay may be ~30–40% lower but must be validated per application. The 74LCX02M datasheet confirms this condition in the AC Electrical Characteristics table.

Can the 74LCX02M drive standard TTL loads?

No-the 74LCX02M is not designed to drive legacy TTL loads. Its output VOH minimum is V_CC – 0.1 V (e.g., 3.2 V at 3.3 V), which falls below the 2.4 V VIH minimum required by standard TTL. However, it fully interfaces with LVTTL, LVCMOS, and other 3.3 V logic families. When interfacing with 5 V TTL, an external level shifter or buffer such as the 74LVC245 is required. This limitation is inherent to the 74LCX02M's CMOS output architecture and is consistent across the LCX family.

Is the 74LCX02M pin-compatible with older 74HC02 or 74LS02 devices?

No-the 74LCX02M uses a 14-pin TSSOP package (Case 948G), whereas standard 74HC02 and 74LS02 are typically offered in 14-pin SOIC or PDIP packages with identical pinouts but different physical dimensions and thermal characteristics. While the logic function and pin numbering (1–14) match the industry-standard 74xx02 layout, PCB layout changes are required to accommodate the smaller TSSOP footprint and 0.65 mm pitch. The 74LCX02M datasheet confirms its pinout matches the generic 74xx02 configuration but requires mechanical redesign for drop-in replacement.