Texas Instruments SN74LVT244BPW

Overview

SN74LVT244BPW 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 dual 4-bit drivers with independent output-enable (OE) controls, supports hot insertion via I_off and power-up 3-state, and operates down to 2.7 V for unregulated battery systems - used in backplane interface and bus isolation in industrial control modules.

For engineers reviewing the SN74LVT244BPW datasheet, SN74LVT244BPW pinout, SN74LVT244BPW application, or SN74LVT244BPW equivalent, key selection criteria include 3.3-V supply compatibility with 5-V TTL interfacing, 20-pin TSSOP package thermal performance (θ_JA = 83°C/W), guaranteed 3.5 ns max propagation delay at 3.3 V, and I_off protection enabling safe hot-plug operation in modular I/O systems.

Technical Context

The SN74LVT244BPW implements two independent 4-bit noninverting buffer sections, each controlled by a dedicated OE input (1OE and 2OE). When OE is low, data passes from A inputs to Y outputs; when high, outputs enter high-impedance state. The device uses Advanced BiCMOS Technology (ABT) to achieve fast switching while maintaining low power consumption and robust noise immunity.

Its I_off circuitry disables outputs during power-down to prevent current backflow, and power-up 3-state ensures outputs remain high-Z during V_CC ramp-up. Absolute maximum ratings allow 5.5-V input tolerance and −0.5 V to 7 V output voltage range in high-Z state - critical for interoperability across legacy 5-V and modern 3.3-V subsystems.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.6 mm × 4.4 mm, 1.2 mm max height, 0.65 mm pitch, exposed thermal pad optional per design. Pin 1 index located at top-left corner with beveled edge marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH244APW and 74ALVC244PW, the SN74LVT244BPW uniquely combines 5-V input tolerance, hot-insertion safety, and 64-mA drive in a single TSSOP-20 package - making it the only option for legacy-compatible, field-serviceable industrial backplanes.

Availability

SN74LVT244BPW is available at Aetrix Electronics and suitable for industrial control backplanes, modular I/O systems, and test equipment signal conditioning requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74LVT244BPW 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 connectivity technologies with over 90 years of innovation in industrial, automotive, and communications markets.

The SN74LVT244BPW belongs to TI's ABT logic family, engineered for robust mixed-voltage interfacing in harsh industrial environments where reliability, hot-swap capability, and legacy system compatibility are mandatory.

FAQ

What is the maximum operating temperature range for the SN74LVT244BPW?

The SN74LVT244BPW is rated for operation from −40°C to +85°C ambient temperature. This industrial-grade range is validated across all electrical parameters in the datasheet, including propagation delay, output drive, and I_off performance - ensuring reliable function in factory-floor PLCs and outdoor telecom equipment where thermal cycling occurs.

Does the SN74LVT244BPW support 5-V input signals while powered at 3.3 V?

Yes, the SN74LVT244BPW explicitly supports 5-V-tolerant inputs at 3.3-V V_CC, with VIH specified at 2.0 V minimum and absolute maximum input voltage rated to 5.5 V. This capability is confirmed in the "Supports Mixed-Mode Signal Operation" feature and verified in the recommended operating conditions table - enabling direct connection to legacy 5-V TTL buses without external level shifters.

How does the SN74LVT244BPW handle power-up sequencing to avoid bus conflicts?

The SN74LVT244BPW incorporates power-up 3-state circuitry that forces outputs into high-impedance during V_CC ramp-up, regardless of OE state. This behavior, combined with I_off protection, prevents bus contention and back-current flow - critical for hot-plug applications. The datasheet specifies Δt/ΔV_CC ≤ 200 μs/V to ensure proper activation of this feature.

What is the thermal resistance (θ_JA) of the SN74LVT244BPW in its TSSOP package?

The SN74LVT244BPW in the PW (TSSOP-20) package has a junction-to-ambient thermal resistance of 83°C/W, as published in the Absolute Maximum Ratings table. This value assumes standard JEDEC 2-layer board conditions and guides thermal design for continuous 64-mA per-output operation - requiring derating above 60°C ambient to maintain junction temperature below 125°C.

Can unused inputs on the SN74LVT244BPW be left floating?

No, all unused inputs on the SN74LVT244BPW must be tied to V_CC or GND to ensure stable operation and prevent increased ICC or oscillation. This requirement is explicitly stated in Note 5 of the Recommended Operating Conditions section and reinforced in TI application report SCBA004 - floating CMOS inputs cause unpredictable current draw and potential latch-up in ABT logic families.