Texas Instruments SN74AVCH8T245RHLR

Overview

SN74AVCH8T245RHLR from Texas Instruments is an 8-bit dual-supply noninverting bus transceiver with configurable level-shifting between 1.2V–3.6V rails on both A and B ports, 3-state outputs, bus-hold circuitry, VCC isolation, and Ioff partial-power-down support. It enables bidirectional voltage translation in mixed-voltage systems such as FPGA-to-ASIC interconnects or SoC peripheral expansion.

For engineers reviewing the SN74AVCH8T245RHLR datasheet, SN74AVCH8T245RHLR pinout, SN74AVCH8T245RHLR application, or SN74AVCH8T245RHLR equivalent, key selection criteria include dual-rail supply flexibility (VCCA/VCCB = 1.2V–3.6V), 4.6-V I/O tolerance, 320Mbps max data rate (at ≥1.8V supplies), bus-hold elimination of external resistors, and VQFN-24 (RHL) thermal performance (RθJB = 15.7°C/W).

Technical Context

The SN74AVCH8T245RHLR implements a fully configurable dual-rail architecture where DIR and OE inputs are referenced exclusively to VCCA, while A-port I/Os track VCCA and B-port I/Os track VCCB - enabling asymmetric voltage translation (e.g., 1.8V ↔ 3.3V). Its bus-hold circuitry actively sustains undriven inputs at valid logic levels without external components.

VCC isolation ensures high-impedance outputs when either VCCA or VCCB is at GND, and Ioff limits current backflow during partial power-down. The device supports asynchronous bidirectional data flow controlled by DIR, with OE enabling/disabling all outputs simultaneously - critical for hot-swap and power-gated subsystems.

Key Specifications

Pinout & Package

SN74AVCH8T245RHLR uses a 24-pin VQFN package (RHL) with 5.5 mm × 3.5 mm footprint, wettable flank leads, and exposed thermal pad for enhanced heat dissipation (RθJB = 15.7°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC8T245RHLR and TXB0108RGER, SN74AVCH8T245RHLR uniquely delivers dual-rail independence, VCC isolation, and bus-hold - making it the only option for robust, high-speed, mixed-voltage parallel bus translation with power sequencing safety.

Availability

SN74AVCH8T245RHLR is available at Aetrix Electronics and suitable for FPGA interconnects, industrial PLC backplanes, enterprise SSD expansion, and automotive ADAS sensor hubs requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SN74AVCH8T245RHLR 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 logic interface solutions.

The SN74AVCH8T245 belongs to TI's AVC logic family, designed specifically for low-voltage, high-speed, mixed-rail system interfacing - targeting applications demanding voltage translation, bus isolation, and power-aware operation.

FAQ

What voltage ranges does SN74AVCH8T245RHLR support on its A and B ports?

SN74AVCH8T245RHLR supports independent supply voltages from 1.2V to 3.6V on both VCCA (A port) and VCCB (B port), enabling translation between any combination of 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V logic domains. This flexibility eliminates the need for external level-shifting circuitry in mixed-voltage systems.

How does the bus-hold feature in SN74AVCH8T245RHLR eliminate external resistors?

The SN74AVCH8T245RHLR integrates active bus-hold circuitry on all A- and B-port I/Os, providing ±25μA to ±100μA sustaining current depending on supply voltage. This holds undriven inputs at valid logic levels, removing the need for external pullup or pulldown resistors - reducing BOM cost, PCB area, and potential signal integrity issues.

Can SN74AVCH8T245RHLR operate safely when one supply rail is powered down?

Yes. SN74AVCH8T245RHLR includes VCC isolation and Ioff functionality: when either VCCA or VCCB is at GND, outputs automatically enter high-impedance mode, and Ioff limits leakage to ±0.1μA. This prevents back-current flow and enables safe power sequencing in multi-rail systems - a critical capability not found in standard LVC transceivers.

What is the maximum data rate supported by SN74AVCH8T245RHLR?

SN74AVCH8T245RHLR supports up to 320Mbps when both VCCA and VCCB are ≥1.8V, and 170Mbps when either supply is ≤1.8V. Propagation delays as low as 2.3ns (A→B, VCCA=3.3V/VCCB=3.3V) and fast enable/disable times (<5ns) ensure timing compliance in high-speed parallel interfaces like memory expansion buses.

Is SN74AVCH8T245RHLR compatible with 5V-tolerant systems?

While SN74AVCH8T245RHLR operates from 1.2V to 3.6V supplies, its I/Os are rated for 4.6V absolute maximum - allowing safe interfacing with 3.3V-tolerant peripherals and limited 5V signaling (e.g., open-drain 5V I²C pulled to 3.3V). However, it is not a full 5V-tolerant device; sustained 5V application exceeds its absolute maximum rating and is not recommended.