Nexperia USA Inc. 74LVC244ABQ/AUX

Overview

74LVC244ABQ/AUX from Nexperia is an octal 3-state buffer/line driver in DHVQFN20 (SOT764-1) package, operating from 1.2 V to 3.6 V supply. It features two independent 4-bit sections (1A0–1A3/1Y0–1Y3 and 2A0–2A3/2Y0–2Y3), dual active-low output enables (1OE, 2OE), Schmitt-trigger inputs for noise immunity, and IOFF partial power-down protection. Used in bidirectional bus interfacing between mixed-voltage domains (e.g., 3.3 V microcontroller to 5 V peripheral).

For engineers reviewing the 74LVC244ABQ/AUX datasheet, 74LVC244ABQ/AUX pinout, 74LVC244ABQ/AUX application, or 74LVC244ABQ/AUX equivalent, key selection criteria include 3-state timing (tpd ≤ 7.5 ns at 3.3 V), overvoltage-tolerant inputs (to 5.5 V), bus hold capability (on 74LVCH244A variant), thermal-enhanced QFN footprint, and JEDEC-compliant voltage ranges (JESD8-7A/5A/C).

Technical Context

This device implements dual independent 4-bit non-inverting buffers with high-impedance 3-state outputs controlled by separate OE signals. Each section drives up to 24 mA (sink/source) at VCC = 3.0 V, with propagation delay as low as 2.9 ns (typ) and enable/disable times under 9.5 ns (max) across full temperature range (−40 °C to +125 °C).

Schmitt-trigger inputs tolerate slow-rising/falling edges (Δt/ΔV down to 10 ns/V), while IOFF circuitry blocks backflow current during partial power-down. Input voltage tolerance to 5.5 V enables safe interfacing with 5 V logic without level shifters, and bus hold (on LVCH variant) eliminates external pull-ups on data lines.

Key Specifications

Pinout & Package

DHVQFN20 (SOT764-1) package: 2.5 × 4.5 × 0.85 mm body, 0.5 mm pitch, no leads, thermally enhanced exposed pad (GND-connected per datasheet recommendation). Pin 1 index area marked on top surface; terminal 1 is 1Y3 (output), terminal 20 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74LVCH244ABQ, the 74LVC244ABQ trades bus hold for lower quiescent current and reduced input leakage-ideal for always-on sensing nodes. Versus SN74LVC244APWR, its DHVQFN package delivers superior thermal performance and 30% smaller PCB area, critical for space-constrained medical and automotive modules.

Availability

74LVC244ABQ/AUX is available at Aetrix Electronics and suitable for industrial PLC backplane interfaces, automotive body control modules, embedded test equipment signal conditioning, and medical diagnostic data acquisition requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for 74LVC244ABQ/AUX 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 MOSFET solutions for automotive, industrial, and consumer markets.

The 74LVC series targets low-voltage, high-speed digital interfacing in space- and power-constrained systems, emphasizing robustness, JEDEC compliance, and seamless integration across mixed-supply architectures.

FAQ

Is the 74LVC244ABQ/AUX pin-compatible with the 74LVCH244ABQ?

Yes-both share identical DHVQFN20 (SOT764-1) pinout, electrical specifications, and timing characteristics. The only functional difference is the presence of bus hold circuitry on all data inputs in the LVCH variant, which is absent in the LVC version. No layout change is required for substitution.

Can this device safely interface a 3.3 V FPGA to a 5 V DAC without external level shifters?

Yes. Inputs tolerate up to 5.5 V regardless of VCC level, allowing direct connection of 5 V DAC outputs to 74LVC244ABQ/AUX inputs. Outputs swing rail-to-rail (0 V to VCC), so a 3.3 V FPGA receives clean 0–3.3 V logic levels. No external components are needed for voltage translation.

What is the recommended PCB layout practice for the exposed thermal pad?

The exposed pad (terminal 10, labeled "GND(1)") must be soldered to a solid PCB ground plane using ≥ 9 thermal vias (0.3 mm diameter, spaced ≤ 1 mm apart) to ensure optimal thermal performance and mechanical reliability. Floating or unconnected pads cause excessive junction temperature rise and potential solder joint fatigue.

Does the IOFF feature require external circuitry to function?

No. IOFF is fully integrated and activates automatically when VCC drops to 0 V. It disables output drivers and blocks current flow between powered and unpowered sections of a bus-no external control signals, resistors, or configuration registers are required. This behavior is guaranteed across −40 °C to +125 °C.