Texas Instruments SN74LVT244BNSR

Overview

SN74LVT244BNSR 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 input systems and 3.3-V V_CC. It features two independent 4-bit channels, I_off and power-up 3-state for hot insertion, supports unregulated battery operation down to 2.7 V, and delivers t_PLH/t_PHL ≤ 3.5 ns at V_CC = 3.3 V - used in backplane bus interface and FPGA I/O expansion.

For engineers reviewing the SN74LVT244BNSR datasheet, SN74LVT244BNSR pinout, SN74LVT244BNSR application, or SN74LVT244BNSR equivalent, key selection criteria include 3-state enable timing (t_PZH/t_PZL ≤ 5.3 ns), output drive capability (I_OL = 64 mA), hot-insertion support via I_off, latch-up immunity (>100 mA), and compatibility with 5-V TTL inputs while operating at 3.3-V supply.

Technical Context

The SN74LVT244BNSR implements Advanced BiCMOS Technology (ABT) logic with dual independent 4-bit noninverting buffers, each controlled by a dedicated output-enable (OE) input. Its architecture enables simultaneous bidirectional voltage translation: 5-V-tolerant inputs accept TTL-level signals while driving 3.3-V CMOS-compatible outputs.

It integrates I_off circuitry that disables outputs during power-down to prevent current backflow, and power-up 3-state logic that holds outputs high-impedance until V_CC stabilizes - critical for live insertion in modular backplanes and hot-swap server I/O cards.

Key Specifications

Pinout & Package

SOP-20 (NS package), 7.5 mm × 13.0 mm body, 0.65 mm pitch, 1.2 mm max height, exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH244A and 74ALVC244, the SN74LVT244BNSR uniquely combines 5-V-tolerant inputs, I_off-enabled hot insertion, and 64-mA drive - making it the only option qualified for live-replaceable 100-MHz bus interface in telecom and industrial systems.

Availability

SN74LVT244BNSR is available at Aetrix Electronics and suitable for backplane bus interface, FPGA I/O expansion, hot-swap server I/O cards, and industrial PLC communication modules requiring stable component supply across extended temperature ranges (−40°C to +85°C).

Supply support for SN74LVT244BNSR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The SN74LVT244BNSR belongs to TI's ABT logic family, engineered for high-speed, mixed-voltage system interfacing - specifically targeting backplane, modular computing, and hot-pluggable infrastructure where reliability under dynamic power conditions is critical.

FAQ

What is the maximum input voltage the SN74LVT244BNSR can tolerate?

The SN74LVT244BNSR accepts input voltages up to 7 V, enabling direct interface with 5-V TTL logic while operating from a 3.3-V supply. This 5-V-tolerant input capability is explicitly specified in the absolute maximum ratings and electrical characteristics tables of the official datasheet, eliminating the need for external level-shifting components in mixed-voltage systems.

Does the SN74LVT244BNSR support hot insertion?

Yes, the SN74LVT244BNSR supports hot insertion through integrated I_off circuitry and power-up 3-state logic. When V_CC is 0 V, I_off limits current flow to ±100 μA, preventing backflow damage. During power-up, outputs remain in high-impedance until V_CC stabilizes - both features are fully characterized and guaranteed per TI's production test flow for SN74LVT244BNSR.

What is the thermal resistance (θ_JA) of the SN74LVT244BNSR in its NS package?

The SN74LVT244BNSR in the SOP-20 (NS) package has a junction-to-ambient thermal resistance (θ_JA) of 60°C/W, as documented in the "Absolute Maximum Ratings" section of the SCAS354J datasheet. This value assumes standard JEDEC High-K test board conditions and is used for worst-case junction temperature estimation under continuous DC loading.

Can unused inputs on the SN74LVT244BNSR be left floating?

No, all unused inputs on the SN74LVT244BNSR must be tied to either V_CC or GND to ensure proper device operation and avoid undefined logic states. This requirement is explicitly stated in Note 5 of the "Recommended Operating Conditions" section of the datasheet and is critical to prevent increased ICC, oscillation, or excessive power consumption due to floating CMOS inputs.

What is the minimum V_CC required for functional operation of the SN74LVT244BNSR?

The SN74LVT244BNSR operates functionally down to 2.7 V V_CC, as defined in the "Recommended Operating Conditions" table. At this voltage, it maintains full 5-V input tolerance, guaranteed 3-state behavior, and meets all AC timing specifications including t_PLH ≤ 3.8 ns - supporting direct connection to unregulated battery supplies in portable and industrial equipment.