Texas Instruments SN74LV245ATRGYR

Overview

SN74LV245ATRGYR from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous two-way data communication between A and B buses in 4.5–5.5 V systems. It features direction control (DIR), output enable (OE), TTL-compatible inputs, 3.5 ns typical propagation delay at 5 V, and Ioff support for partial-power-down mode.

For engineers reviewing the SN74LV245ATRGYR datasheet, SN74LV245ATRGYR pinout, SN74LV245ATRGYR application, or SN74LV245ATRGYR equivalent, this device is selected for bidirectional level-shifting, bus isolation in mixed-voltage systems, and high-speed data routing where low ground bounce (<0.8 V) and undershoot control (>2.3 V VOHV) are critical.

Technical Context

This transceiver implements dual 8-bit bidirectional channels controlled by a single DIR input and a shared OE input. Signal flow direction (A→B or B→A) is determined solely by DIR logic level, while OE independently places all outputs in high-impedance state-enabling true bus isolation without timing constraints on control signals.

It supports mixed-mode voltage operation across all ports and includes Ioff circuitry that disables outputs during power-down to prevent backflow current. Absolute maximum ratings allow up to 7 V on inputs/outputs, but recommended operation is strictly 4.5–5.5 V with –40°C to 125°C ambient range (note: RGY package rated –40°C to 85°C).

Key Specifications

Pinout & Package

VQFN-20 (RGY) package: 3.5 mm × 4.5 mm, 0.5 mm pitch, exposed thermal pad (Pin 21), 1 mm max height. Requires soldering of thermal pad for mechanical stability and thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LV245ATRGYR, SN74LVC245AQPWRQ1 offers automotive qualification but sacrifices 5 V operation and Ioff protection, while 74LVX245M lacks both voltage flexibility and modern power-down safety-making SN74LV245ATRGYR the optimal choice for robust 5 V mixed-signal industrial interfaces.

Availability

SN74LV245ATRGYR is available at Aetrix Electronics and suitable for industrial automation, medical instrumentation, and test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant VQFN packaging.

Supply support for SN74LV245ATRGYR 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 with over 50 years of innovation in high-reliability interface ICs.

The SN74LV245ATRGYR belongs to TI's LV logic family, engineered for low-voltage, high-speed bidirectional bus interfacing in industrial and automotive environments where noise immunity and power-down safety are essential.

FAQ

What is the operating temperature range for SN74LV245ATRGYR?

The SN74LV245ATRGYR is specified for –40°C to +85°C ambient operation. This differs from other package variants (e.g., DB, DGV, NS, PW) which support –40°C to +125°C. The RGY package's thermal resistance (θJA = 37 °C/W) is optimized for this narrower range, and derating is required above 85°C.

Does SN74LV245ATRGYR support 3.3 V operation?

No, SN74LV245ATRGYR is not rated for 3.3 V operation. Its absolute minimum VCC is 4.5 V, and recommended operating range is strictly 4.5–5.5 V. Attempting 3.3 V supply will result in undefined logic levels, excessive propagation delay, and potential failure to meet VOL/VOH specifications.

How should OE and DIR be biased during power-up?

OE must be held high (via pullup to VCC) during power-up to ensure outputs remain in high-impedance state until system initialization completes. DIR has no internal bias; its state determines initial data direction but does not affect isolation-only OE controls bus disconnection.

Is the exposed thermal pad on SN74LV245ATRGYR electrically connected?

Yes, the exposed thermal pad (Pin 21) on SN74LV245ATRGYR is internally connected to GND. It must be soldered to a PCB thermal pad tied to the system ground plane to meet thermal and mechanical specifications-failure to do so risks exceeding θJA and causing premature thermal shutdown or solder joint fatigue.

Can SN74LV245ATRGYR replace SN74LV245A in existing designs?

Yes, SN74LV245ATRGYR is functionally and electrically identical to SN74LV245A, differing only in package (RGY vs. legacy packages). Pinout, timing, and DC specs match exactly-but layout must accommodate the 3.5×4.5 mm VQFN footprint, thermal pad, and 0.5 mm pitch, requiring PCB redesign.