Texas Instruments SN74ALVC245RGYRG4

Overview

SN74ALVC245RGYRG4 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 SN74ALVC245RGYRG4 datasheet, SN74ALVC245RGYRG4 pinout, SN74ALVC245RGYRG4 application, or SN74ALVC245RGYRG4 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 interfacing.

Technical Context

The SN74ALVC245RGYRG4 implements dual-directional 8-bit data flow controlled by DIR (direction) and OE (output enable) inputs. Its CMOS design supports true bidirectional operation without internal latching, enabling real-time bus arbitration in shared-memory or peripheral interconnect systems. The device uses standard positive-logic control: DIR = H enables A→B transmission; DIR = L enables B→A transmission; OE = H forces all outputs into high-impedance state.

It meets JESD 17 latch-up immunity (>250 mA), supports hot-insertion via controlled 3-state transitions, and maintains valid logic thresholds across its full 1.65–3.6-V supply range. Input and output voltage tolerances extend to VCC + 0.5 V on I/O ports, allowing safe interfacing with higher-voltage drivers when OE is asserted.

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 PCB solder connection 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 SN74AVC245RHLR, the SN74ALVC245RGYRG4 delivers optimal balance of speed (3.4 ns), industrial temperature range, thermal reliability (exposed pad), and low-power operation - making it preferred for cost-sensitive, thermally demanding industrial bus interfaces where 5-V tolerance is unnecessary.

Availability

SN74ALVC245RGYRG4 is available at Aetrix Electronics and suitable for industrial automation, FPGA-based prototyping, and mixed-voltage communication subsystems requiring stable component supply and long-term production continuity.

Supply support for SN74ALVC245RGYRG4 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 SN74ALVC245RGYRG4 belongs to TI's ALVC (Advanced Low-Voltage CMOS) logic family, engineered for low-voltage, high-speed bidirectional bus interfacing in industrial, computing, and communications equipment where power efficiency and timing precision are critical.

FAQ

What is the maximum operating frequency supported by the SN74ALVC245RGYRG4?

The SN74ALVC245RGYRG4 does not specify a maximum clock frequency, but its 3.4-ns maximum propagation delay at 3.3 V supports reliable data toggling up to approximately 200 MHz in point-to-point configurations. Actual usable frequency depends on bus loading, trace length, and termination - for sustained 250+ MHz operation, consider the faster SN74AVC245RHLR variant.

Can the SN74ALVC245RGYRG4 interface a 1.8-V microcontroller with a 3.3-V peripheral?

Yes - the SN74ALVC245RGYRG4 operates across 1.65–3.6 V and supports bidirectional voltage translation. When powered at 1.8 V, it safely accepts 3.3-V inputs (within VCC + 0.5 V limit) and drives 1.8-V outputs; when powered at 3.3 V, it drives 3.3-V outputs and accepts 1.8-V inputs as valid logic LOW. No external biasing is required.

Is the exposed thermal pad on the RGY package required to be connected to ground?

No - the exposed thermal pad (Pin 21) on the SN74ALVC245RGYRG4 RGY package must be soldered to a PCB copper area for thermal and mechanical stability, but it is not internally connected to GND. TI recommends connecting it to a low-impedance thermal plane (not necessarily ground) and using ≥4 thermal vias to inner layers for optimal heat dissipation in continuous operation.

How should OE and DIR be handled during power-up to avoid bus contention?

To ensure high-impedance state at power-up, OE must be held HIGH before VCC reaches 1.5 V. TI recommends tying OE to VCC through a 10-kΩ pull-up resistor. DIR may float initially but should be driven after power stabilization; uncontrolled DIR states cause undefined data flow direction, so firmware or hardware initialization must assert DIR before enabling OE.

Does the SN74ALVC245RGYRG4 support hot-swap or live-insertion?

Yes - the SN74ALVC245RGYRG4 meets JESD 17 latch-up immunity (>250 mA) and features controlled 3-state transitions. When OE is held HIGH during insertion, all I/Os remain in high-impedance mode regardless of input voltage, preventing back-driving or bus contention. However, VCC must ramp monotonically and OE must be asserted before applying signal voltages to I/O pins.