Texas Instruments SN74ALVC245RGYR

Overview

SN74ALVC245RGYR from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for bidirectional asynchronous data transfer between 1.65-V to 3.6-V buses. It features ±24-mA output drive at 3.3 V, 3.4-ns max propagation delay, and operates across –40°C to 85°C. Used in level-shifting interfaces between mixed-voltage logic domains in embedded controllers and FPGA I/O expansion.

For engineers reviewing the SN74ALVC245RGYR datasheet, SN74ALVC245RGYR pinout, SN74ALVC245RGYR application, or SN74ALVC245RGYR equivalent, key selection criteria include voltage translation capability (1.65–3.6 V), direction-control logic behavior, 3-state isolation timing (ten/tdis), thermal performance of the RGY package, and compatibility with high-speed digital bus architectures requiring low skew and rail-to-rail CMOS signaling.

Technical Context

The SN74ALVC245RGYR implements dual-bus bidirectional data flow controlled by DIR (direction) and OE (output enable) inputs. Its 8-bit A↔B channel architecture supports simultaneous transmission in either direction based on DIR state, while OE independently places all outputs in high-impedance mode for bus isolation. The device uses advanced ALVC (Advanced Low-Voltage CMOS) process technology optimized for low-voltage operation without sacrificing speed or drive strength.

It meets JESD 17 latch-up immunity (>250 mA), supports hot-insertion via controlled I/O clamp current (±50 mA), and exhibits input transition rate tolerance up to 10 ns/V. The RGY package's exposed thermal pad enables efficient heat dissipation during sustained ±24-mA output loading, critical for dense PCB layouts in industrial and communications equipment.

Key Specifications

Pinout & Package

VQFN-20 (RGY) package: 3.5 mm × 4.5 mm, 0.5-mm pitch, 1-mm max height, with exposed thermal pad (Pin 21) requiring solder connection to PCB ground plane for thermal and mechanical integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245APWR and 74AVC8T245PW, the SN74ALVC245RGYR delivers superior thermal performance in space-constrained layouts, consistent ±24-mA drive across its full 1.65–3.6-V range, and drop-in compatibility with existing RGY-footprinted designs-making it optimal for industrial and automotive upgrades where reliability and layout reuse are critical.

Availability

SN74ALVC245RGYR is available at Aetrix Electronics and suitable for industrial automation, FPGA interconnect, and automotive infotainment systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74ALVC245RGYR 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 decades of experience in high-reliability logic and interface solutions.

The SN74ALVC245RGYR belongs to TI's ALVC logic family, engineered specifically for low-voltage, high-speed bidirectional bus interfacing in mixed-signal systems where power efficiency, timing precision, and robust ESD/latch-up performance are essential.

FAQ

What is the recommended power-up sequence for SN74ALVC245RGYR?

TI recommends tying OE to VCC through a pull-up resistor during power-up to ensure outputs remain in high-impedance state until valid logic levels stabilize. For SN74ALVC245RGYR, a 10-kΩ resistor suffices given its ±5-µA input leakage; this prevents bus contention during VCC ramp, especially critical in multi-rail systems where A and B buses may power up at different rates.

Does SN74ALVC245RGYR support hot-swap operation?

Yes, SN74ALVC245RGYR supports hot-swap operation due to its ±50-mA IOK rating, JESD17 latch-up immunity (>250 mA), and rail-to-rail input tolerance (–0.5 V to VCC+0.5 V). When used with proper series current-limiting resistors and OE-controlled isolation, it safely handles live insertion into powered backplanes without damaging connected circuitry.

Can SN74ALVC245RGYR translate between 1.8-V and 3.3-V logic domains?

Yes, SN74ALVC245RGYR operates across 1.65–3.6 V, enabling seamless bidirectional translation between 1.8-V and 3.3-V buses. Its VIH/VIL thresholds scale with VCC (e.g., VIH = 0.65×VCC at 1.65–1.95 V), ensuring reliable recognition of logic levels from either domain without external biasing or threshold adjustment.

What is the function of the exposed thermal pad on the RGY package of SN74ALVC245RGYR?

Pin 21 (exposed thermal pad) on SN74ALVC245RGYR must be soldered to a PCB copper pour connected to GND. This reduces θJA from 37°C/W to <25°C/W in typical layouts, dissipating heat generated during ±24-mA output loading and improving long-term reliability in thermally constrained enclosures.

How does the DIR input affect data flow direction in SN74ALVC245RGYR?

In SN74ALVC245RGYR, DIR determines real-time data direction: DIR = low enables B→A transfer; DIR = high enables A→B transfer. This occurs only when OE = low; if OE = high, all outputs go high-impedance regardless of DIR state. The DIR signal is sampled asynchronously but affects propagation path immediately upon stabilization.