Texas Instruments SN74LVTH244ADB

Overview

SN74LVTH244ADB from Texas Instruments is a 3.3-V ABT octal buffer/driver with 3-state outputs, designed for mixed-mode signal operation between 5-V inputs and 3.3-V V_CC. It features bus-hold on data inputs, I_off support for hot insertion, and operates down to 2.7 V for unregulated battery systems. Used in industrial backplane interfaces and legacy bus bridging where TTL-level compatibility and low-voltage logic coexist.

For engineers reviewing the SN74LVTH244ADB datasheet, SN74LVTH244ADB pinout, SN74LVTH244ADB application, or SN74LVTH244ADB equivalent, key selection criteria include its 20-pin SSOP (DB) package, dual 4-bit channel architecture with independent OE control, ±100 µA I_off, 0.55 V typical V_OL at 64 mA, and bus-hold circuitry eliminating external resistors.

Technical Context

The SN74LVTH244ADB implements two independent 4-bit noninverting buffer/driver channels, each with dedicated output-enable (OE) inputs-1OE controls Y1–Y4, 2OE controls Y1'–Y4'. Its ABT (Advanced BiCMOS Technology) architecture enables TTL-compatible input thresholds while operating from a 3.3-V supply, supporting bidirectional voltage translation without level shifters.

It integrates active bus-hold circuitry on all A-inputs (±750 µA hold current), power-up 3-state logic to prevent bus contention during supply ramp, and I_off protection that disables outputs when V_CC = 0 V, blocking reverse current flow up to ±4.5 V on I/O pins-critical for hot-swap and partial-power-down systems.

Key Specifications

Pinout & Package

SN74LVTH244ADB uses a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm pitch, 7.4 mm × 5.3 mm body size, and 2.0 mm max height per JEDEC MO-150. Pin 1 index is marked by a beveled corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC244APW and SN74AHCT244N, the SN74LVTH244ADB uniquely combines 5-V input tolerance, bus-hold, I_off, and 2.7–3.6 V operation-making it the sole option for robust mixed-voltage hot-swap interfaces without design compromises.

Availability

SN74LVTH244ADB is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy bus bridging, hot-swappable module carriers, and low-power embedded data hubs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVTH244ADB 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The SN74LVTH244ADB belongs to TI's LVTH (Low-Voltage TTL-High-Speed) logic family, engineered for seamless interoperability between 3.3-V logic and legacy 5-V systems in mission-critical industrial infrastructure.

FAQ

What is the maximum output sink current supported by SN74LVTH244ADB?

The SN74LVTH244ADB supports a maximum low-level output current (I_OL) of 64 mA per channel at V_CC = 3 V, as specified in the recommended operating conditions table. This rating ensures reliable driving of standard TTL loads and multiple CMOS inputs while maintaining V_OL ≤ 0.55 V. Exceeding this current may degrade noise margins or cause thermal stress in sustained operation.

Does SN74LVTH244ADB require external pullup resistors on its inputs?

No, SN74LVTH244ADB does not require external pullup or pulldown resistors on its A-inputs because it integrates active bus-hold circuitry. Each input maintains a valid logic level when floating, drawing ±750 µA to hold the state. Using external resistors with the bus-hold feature is explicitly discouraged in the datasheet, as it can cause contention and increased power consumption.

Can SN74LVTH244ADB be used in hot-swap applications?

Yes, SN74LVTH244ADB is explicitly designed for hot-insertion applications. Its I_off circuitry disables outputs when V_CC = 0 V, preventing damaging current backflow, and its power-up 3-state logic ensures outputs remain high-impedance during supply ramp. These features meet the requirements for live module replacement in carrier-card systems without disrupting the host bus.

What is the absolute maximum input voltage rating for SN74LVTH244ADB?

The absolute maximum input voltage (V_I) for SN74LVTH244ADB is −0.5 V to 7 V, as stated in the Absolute Maximum Ratings table. This wide range allows safe interfacing with 5-V TTL signals while operating from a 3.3-V supply, and accommodates transient overshoots up to 7 V without device damage-provided clamp-current limits (±50 mA) are not exceeded.

How does the dual OE architecture of SN74LVTH244ADB benefit system design?

The SN74LVTH244ADB features two independent output-enable inputs (1OE and 2OE), allowing separate control of its two 4-bit channels. This enables precise bus segmentation-for example, gating data and address lanes independently or implementing handshake protocols where one channel signals readiness before enabling the other. It eliminates the need for additional logic gates or multiplexers in multi-lane interface designs.