Texas Instruments SN74AVC2T45DCUT

Overview

SN74AVC2T45DCUT from Texas Instruments is a 2-bit dual-supply bus transceiver enabling bidirectional voltage-level translation between 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V domains. It features independent VCCA (1.2–3.6V) and VCCB (1.2–3.6V) rails, 4.6V I/O overvoltage tolerance, Ioff partial-power-down support, and VCC isolation. It serves as a critical interface IC in mobile SoC interconnects where mixed-voltage subsystems require reliable, low-latency data exchange.

For engineers reviewing the SN74AVC2T45DCUT datasheet, SN74AVC2T45DCUT pinout, SN74AVC2T45DCUT application, or SN74AVC2T45DCUT equivalent, key selection criteria include its dual-rail level-shifting capability, DIR-controlled directionality, guaranteed 240–500 Mbps data rate across voltage combinations, 8-pin VSSOP (DCU) package footprint, and compliance with JESD78 Class II latch-up and JESD22 ESD standards.

Technical Context

This device implements a non-inverting, asynchronous bidirectional transceiver architecture with separate A- and B-port power domains. Direction control is managed solely by the DIR input referenced to VCCA, activating either A→B or B→A data flow without requiring external OE signals.

Its CMOS input structure remains active at all times-requiring defined logic levels on unused ports-and integrates VCC isolation logic that forces both ports into high-impedance when either VCCA or VCCB = GND, preventing false bus states during power sequencing.

Key Specifications

Pinout & Package

SN74AVC2T45DCUT uses the DCU package: 8-pin Very Small Outline Package (VSSOP), body size 2.30 mm × 2.00 mm, 0.5 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC2T45DCUR and TXS0102DCUR, SN74AVC2T45DCUT uniquely combines 500 Mbps speed, full 1.2–3.6V dual-rail configurability, VCC isolation, and Ioff - making it the only option for high-performance, power-sequenced mixed-voltage SoC interconnects.

Availability

SN74AVC2T45DCUT is available at Aetrix Electronics and suitable for smartphone baseband interfaces, server memory subsystems, and notebook embedded controller buses requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SN74AVC2T45DCUT 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 company specializing in analog, embedded processing, and connectivity technologies, with leadership in precision analog and low-power logic solutions.

SN74AVC2T45DCUT belongs to TI's AVC (Advanced Very-low-voltage CMOS) logic family, designed specifically for high-speed, low-voltage bidirectional level translation in portable and power-constrained computing systems.

FAQ

What voltage ranges does the SN74AVC2T45DCUT support on its VCCA and VCCB supplies?

The SN74AVC2T45DCUT supports independent supply voltages from 1.2V to 3.6V on both VCCA and VCCB pins. This enables translation between any pair of standard low-voltage nodes - including 1.2V↔1.5V, 1.2V↔1.8V, 1.8V↔2.5V, 1.8V↔3.3V, and 2.5V↔3.3V - without external components. Operation outside this range violates absolute maximum ratings.

How does the DIR pin control data direction in the SN74AVC2T45DCUT?

In the SN74AVC2T45DCUT, the DIR pin is referenced to VCCA and determines bidirectional flow: when DIR = LOW, data passes from B-port to A-port; when DIR = HIGH, data passes from A-port to B-port. The DIR signal must be driven actively - no internal pullup or pulldown is provided - and must remain stable during data transfer to avoid bus contention.

Does the SN74AVC2T45DCUT support partial power-down, and how is it implemented?

Yes, the SN74AVC2T45DCUT supports partial power-down via its Ioff feature. When either VCCA or VCCB is at 0V, the Ioff circuitry disables all outputs, limiting off-state current to ±1 µA max at 85°C. This prevents damaging back-current flow between powered and unpowered domains - critical for battery-powered sleep modes in smartphones and notebooks.

What is the purpose of the VCC isolation feature in the SN74AVC2T45DCUT?

The VCC isolation feature in the SN74AVC2T45DCUT forces both A- and B-ports into high-impedance when either VCCA or VCCB is at GND. This prevents false logic states (e.g., unintended HIGH or LOW) from appearing on either bus during power-up, power-down, or fault conditions - ensuring clean, deterministic bus behavior in multi-rail systems with independent power sequencing.

Can unused I/O pins on the SN74AVC2T45DCUT be left floating?

No, unused I/O pins on the SN74AVC2T45DCUT must not be left floating. Because the CMOS input structure remains active at all times, floating inputs cause excessive leakage current and potential logic instability. All unused A1, A2, B1, or B2 pins must be tied directly to GND or to their respective supply rail (VCCA or VCCB) to ensure proper operation and reliability.