Nexperia USA Inc. 74LVC244ABZX

Overview

74LVC244ABZX from Nexperia is an octal 3-state buffer/line driver with dual output enables (1OE, 2OE), designed for bidirectional bus interfacing in mixed-voltage systems. It operates from 1.2 V to 3.6 V, tolerates 5.5 V inputs, features Schmitt-trigger inputs for noise immunity, and supports partial power-down via IOFF circuitry. It is used in industrial control backplanes and FPGA I/O expansion where level translation and bus isolation are required.

For engineers reviewing the 74LVC244ABZX datasheet, 74LVC244ABZX pinout, 74LVC244ABZX application, or 74LVC244ABZX equivalent, key selection criteria include its 20-terminal DHXQFN package, 3.6 V max input tolerance, -40 °C to +125 °C temperature range, IOFF-enabled power-down safety, and compatibility with both 3.3 V and 5 V logic domains.

Technical Context

This device implements two independent 4-bit non-inverting buffers, each controlled by a dedicated active-low output enable (1OE for Y0–Y3 group, 2OE for Y0'–Y3' group). All inputs feature Schmitt-trigger action, enabling robust operation with slow-rising signals and reducing susceptibility to noise-induced switching.

The IOFF circuit ensures outputs enter high-impedance state when VCC = 0 V, preventing backflow current during partial power-down - critical for hot-swap and power-gated subsystems. Bus hold functionality is absent in the 74LVC244A variant (present only in 74LVCH244A), confirming this part relies on external termination or system-level hold.

Key Specifications

Pinout & Package

DHXQFN20 (SOT8020-1) package: leadless, 2.0 mm × 3.2 mm × 0.48 mm body, 0.4 mm pitch, 20 terminals, thermal pad (non-soldered or GND-connected per design).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal 3-state buffer applications.

Compared with 74LVC244APW, the 74LVC244ABZX offers superior thermal performance and smaller footprint for high-density layouts; versus SN74LVC244APWR, it provides guaranteed IOFF functionality across the full industrial temperature range, making it the sole choice for mission-critical power-gated systems.

Availability

74LVC244ABZX is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA I/O expansion, automotive body control modules, and test equipment signal conditioning requiring stable component supply across extended temperature ranges.

Supply support for 74LVC244ABZX 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

Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, analog, and discrete components for automotive, industrial, and consumer markets.

The 74LVC244A belongs to Nexperia's LVC (Low-Voltage CMOS) logic family, engineered for low-power, high-noise-immunity interfacing in mixed-voltage embedded systems - especially where space, thermal headroom, and robust power sequencing are critical.

FAQ

Is the 74LVC244ABZX pin-compatible with the 74LVCH244ABZX?

No. While both share the same DHXQFN20 package and pin count, the 74LVCH244ABZX includes bus hold circuitry on all data inputs (1A0–1A3, 2A0–2A3), whereas the 74LVC244ABZX lacks bus hold. This affects input state retention during floating conditions and requires external pull resistors if used in open-bus configurations.

Can the 74LVC244ABZX safely interface a 5 V microcontroller with a 1.8 V FPGA?

Yes - its inputs tolerate up to 5.5 V regardless of VCC, allowing direct connection from 5 V MCU outputs. However, outputs swing between GND and VCC (1.8 V), so driving the FPGA inputs requires verifying that the FPGA's VIH(min) ≤ 1.8 V × 0.7 = 1.26 V, which is typical for 1.8 V I/O standards.

What is the recommended PCB layout for the thermal pad on SOT8020-1?

The exposed thermal pad (terminal 1 index area) has no electrical requirement to be soldered. If connected, it must be either left floating or tied to GND. When grounded, use a minimum of four 0.3 mm thermal vias to an internal GND plane to maintain junction temperature within limits at full load.

Does the 74LVC244ABZX support hot insertion into a live backplane?

Yes - the IOFF circuit ensures outputs go high-impedance when VCC = 0 V, preventing backdrive current into a powered bus. However, input pins remain tolerant to 5.5 V even at 0 V VCC, so live insertion is safe provided VCC ramp-up follows manufacturer-recommended sequencing (GND first, then VCC, then signals).