NXP Semiconductors 74LVCH244APW/AUJ

Overview

74LVCH244APW/AUJ from Nexperia is an octal 3-state buffer/line driver with dual output enables (1OE, 2OE), bus-hold inputs, and overvoltage-tolerant inputs up to 5.5 V. It operates from 1.2 V to 3.6 V supply, supports mixed-voltage translation between 3.3 V and 5 V systems, and features IOFF partial power-down protection. It is used in address/data bus buffering for industrial microcontroller interfaces.

For engineers reviewing the 74LVCH244APW/AUJ datasheet, 74LVCH244APW/AUJ pinout, 74LVCH244APW/AUJ application, or 74LVCH244APW/AUJ equivalent, key selection criteria include bus-hold functionality, 3.6 V max supply, -40 °C to +125 °C temperature range, TSSOP20 package compatibility, and 5.5 V input tolerance in level-shifting designs.

Technical Context

The 74LVCH244APW/AUJ implements two independent 4-bit non-inverting buffers, each controlled by a dedicated active-low output enable (1OE for Y0–Y3, 2OE for Y0–Y3). All inputs feature Schmitt-trigger action and bus-hold circuitry-unique to the LVCH variant-to maintain valid logic states during floating conditions without external pull resistors.

Its IOFF circuitry actively disables outputs and blocks backflow current when VCC = 0 V, enabling hot-swap and partial power-down operation. Input voltage tolerance up to 5.5 V allows direct interfacing with 5 V TTL outputs while powered from 1.8 V or 3.3 V rails, making it suitable for voltage-domain bridging in FPGA I/O expansion and MCU peripheral buses.

Key Specifications

Pinout & Package

TSSOP20 package (SOT360-1), 4.4 mm body width, 0.65 mm pitch, 20-terminal surface-mount plastic thin shrink small outline package.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74LVC244APW and SN74LVC244APWR, the 74LVCH244APW/AUJ uniquely delivers bus-hold functionality and JEDEC-compliant multi-voltage operation-critical for noise-prone industrial buses and mixed-supply FPGA interfaces-without layout or firmware changes.

Availability

74LVCH244APW/AUJ is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, embedded MCU address bus buffering, and FPGA I/O expansion requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for 74LVCH244APW/AUJ 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 delivering high-performance logic, analog, and MOSFET solutions optimized for efficiency, reliability, and miniaturization in industrial and automotive applications.

The 74LVCH244APW/AUJ belongs to Nexperia's LVC/LVCH logic family, engineered specifically for robust voltage translation, bus stability, and power-aware operation in harsh, thermally demanding embedded systems.

FAQ

What is the maximum input voltage the 74LVCH244APW/AUJ can tolerate?

The 74LVCH244APW/AUJ accepts input voltages up to 5.5 V regardless of VCC level, enabling direct interface with 5 V TTL outputs while operating from 1.8 V or 3.3 V supplies. This overvoltage tolerance is guaranteed per datasheet Table 5 and eliminates need for external clamping components in mixed-voltage designs.

Does the 74LVCH244APW/AUJ support partial power-down operation?

Yes, the 74LVCH244APW/AUJ incorporates IOFF circuitry that disables outputs and blocks backflow current when VCC = 0 V. This feature is validated per datasheet Section 1 and ensures safe hot-swap and power sequencing in modular systems where 74LVCH244APW/AUJ may be unpowered while I/O lines remain active.

How does bus-hold functionality work on the 74LVCH244APW/AUJ?

The 74LVCH244APW/AUJ provides bus-hold on all data inputs (1A0–1A3, 2A0–2A3) with ±75 μA sustaining current at VCC = 3.0 V. As specified in Table 6, this circuit actively retains the last valid logic state on floating inputs-preventing metastability and eliminating external pull resistors in applications like unconnected test points or intermittent peripheral connections.

What is the propagation delay of the 74LVCH244APW/AUJ at 3.3 V supply?

At VCC = 3.3 V and Tamb = 25 °C, the 74LVCH244APW/AUJ exhibits typical propagation delay of 2.9 ns (min 1.5 ns, max 5.9 ns) from input to output, and 3.2 ns (min 1.0 ns, max 7.6 ns) from OE to output enable. These values are measured per Figure 4 and Table 7 and ensure compatibility with 100+ MHz digital timing budgets.

Is the 74LVCH244APW/AUJ pin-compatible with the 74LVC244APW?

Yes, the 74LVCH244APW/AUJ is pin-compatible with the 74LVC244APW in the same TSSOP20 (SOT360-1) package, sharing identical pin numbering, electrical interface, and footprint. However, the 74LVCH244APW/AUJ adds bus-hold functionality not present in the 74LVC244APW, making it a functional superset for designs requiring input state retention.