Texas Instruments SN74LVT245BRGYR

Overview

SN74LVT245BRGYR from Texas Instruments is a 3.3-V ABT octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between 3.3-V and 5-V systems. It supports mixed-mode signal operation, features Ioff and power-up 3-state for hot insertion, and delivers propagation delays as low as 1.2 ns at VCC = 3.3 V - enabling use in high-speed industrial backplanes and FPGA-to-ASIC interface bridging.

For engineers reviewing the SN74LVT245BRGYR datasheet, SN74LVT245BRGYR pinout, SN74LVT245BRGYR application, or SN74LVT245BRGYR equivalent, key selection considerations include its VQFN-20 (RGY) package thermal performance (θJA = 37°C/W), 2.7–3.6 V supply range, ±100 µA Ioff at VCC = 0 V, and guaranteed 64 mA sink capability per output - critical for driving terminated parallel buses under hot-swap conditions.

Technical Context

The SN74LVT245BRGYR implements an ABT (Advanced BiCMOS Technology) logic architecture optimized for low-voltage operation while maintaining TTL-compatible input thresholds and 5-V tolerant I/O. Its direction-control (DIR) and output-enable (OE) inputs operate asynchronously to configure data flow from A-to-B or B-to-A buses, with OE asserting high-impedance on all outputs regardless of DIR state.

Internal Ioff circuitry disables outputs when VCC = 0 V, preventing backflow current during partial power-down, and power-up 3-state ensures outputs remain high-Z during supply ramp-up. The device meets JESD 78 Class II latch-up immunity (>100 mA) and exceeds JESD 22 ESD ratings: 2000-V HBM, 200-V MM, and 1000-V CDM.

Key Specifications

Pinout & Package

VQFN-20 (RGY) package: 3.5 mm × 4.5 mm, 0.5 mm pitch, 1 mm max height, 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 SN74LVTH245PWRE4 and SN74ALVC164245GR, the SN74LVT245BRGYR uniquely combines 5-V I/O tolerance, Ioff-enabled hot insertion, and 64 mA drive in a thermally efficient VQFN package - making it the sole choice for legacy-system upgrades requiring plug-and-play interoperability.

Availability

SN74LVT245BRGYR is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA-to-peripheral bridges, hot-swappable module carriers, and automated test equipment fixtures requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVT245BRGYR 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 solutions, with over 50 years of innovation in logic and interface ICs.

The SN74LVT245BRGYR belongs to TI's ABT logic family, engineered for high-speed, mixed-voltage system interconnect - specifically targeting industrial, telecom, and computing applications demanding robustness, low latency, and seamless voltage-domain bridging.

FAQ

What is the maximum operating temperature range for SN74LVT245BRGYR?

The SN74LVT245BRGYR is specified for operation from −40°C to +85°C ambient temperature. This industrial-grade range is validated across all electrical parameters including propagation delay, output drive strength, and Ioff leakage, ensuring reliable performance in factory automation, outdoor telecom enclosures, and motor control cabinets without derating.

Does SN74LVT245BRGYR support hot insertion, and how is it implemented?

Yes, SN74LVT245BRGYR supports hot insertion via two integrated features: Ioff circuitry disables outputs when VCC = 0 V to prevent backflow current, and power-up 3-state holds all outputs in high-impedance during supply ramp-up. These functions are inherent to the ABT process and require no external components - verified per JESD78 Class II latch-up and JESD22 ESD standards.

Can SN74LVT245BRGYR interface directly between 3.3-V and 5-V logic systems?

Yes, SN74LVT245BRGYR supports mixed-mode signal operation: its inputs and outputs tolerate up to 5.5 V while operating from a 3.3-V supply (VCC = 2.7–3.6 V). This allows direct connection to 5-V TTL peripherals without external level shifters, provided VI does not exceed 5.5 V and VO remains within −0.5 V to VCC + 0.5 V during active drive.

What is the thermal resistance (θJA) of the SN74LVT245BRGYR package, and why does it matter?

The SN74LVT245BRGYR in the RGY (VQFN-20) package has θJA = 37°C/W, measured per JESD51-5. This value is significantly lower than SOIC (58°C/W) or TSSOP (83°C/W) variants, meaning it dissipates heat more efficiently - allowing higher sustained current drive (e.g., 64 mA per output) without exceeding junction temperature limits on standard 2-layer PCBs.

How should the OE pin be handled during power-up to ensure safe operation of SN74LVT245BRGYR?

To guarantee high-impedance outputs during power-up, OE must be held high (inactive) until VCC stabilizes. TI recommends tying OE to VCC through a pullup resistor; minimum value depends on the driver's sink capability - typically 4.7 kΩ suffices for most microcontroller GPIOs. This prevents bus contention before system initialization completes.