Texas Instruments SN74LVC2T45DCUTG4

Overview

SN74LVC2T45 from Texas Instruments is a dual-bit, dual-supply noninverting bus transceiver enabling bidirectional voltage translation between 1.65 V and 5.5 V rails (e.g., 1.8 V ↔ 3.3 V, 3.3 V ↔ 5 V). It features configurable direction control (DIR referenced to VCCA), ±24-mA output drive at 3.3 V, 4-μA maximum ICC, and VCC isolation. It is used in mixed-voltage I²C, UART, and GPIO interconnects between SoCs and peripherals.

For engineers reviewing the SN74LVC2T45 datasheet, SN74LVC2T45 pinout, SN74LVC2T45 application, or SN74LVC2T45 equivalent, key selection criteria include dual-rail operating range (1.65–5.5 V per supply), directional control logic referenced to VCCA, Ioff-enabled partial-power-down support, high-speed capability up to 420 Mbps (3.3 V → 5 V), and NanoFree™ package compatibility with space-constrained PCB layouts.

Technical Context

The SN74LVC2T45 implements asynchronous bidirectional data flow controlled by a single DIR input referenced to VCCA. Each port (A and B) operates independently across its full 1.65 V–5.5 V supply range, enabling translation between any two standard logic nodes without level-shifter ICs or discrete solutions. The device uses CMOS push-pull outputs with balanced sourcing/sinking capability.

VCC isolation ensures both ports enter high-impedance when either VCCA or VCCB = GND, preventing backfeed during power sequencing. Ioff circuitry disables I/Os during partial power-down, limiting leakage to ±2 µA per pin while maintaining signal integrity across unpowered domains.

Key Specifications

Pinout & Package

SN74LVC2T45 is packaged in an 8-pin SM8 (DCT) package measuring 2.95 mm × 4.00 mm, part of Texas Instruments' NanoFree™ wafer-chip-scale family. This leadless, near-die-size package eliminates bond wires and reduces parasitic inductance for improved signal integrity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TXS0102DCUR and SN74AVC2T245DCUR, SN74LVC2T45 uniquely combines 1.65–5.5 V dual-rail flexibility, VCC isolation, Ioff protection, and 420 Mbps throughput - making it the only option qualified for industrial and automotive mixed-voltage interconnects with safety-critical power sequencing.

Availability

SN74LVC2T45 is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, server management, and medical wearable design requiring stable component supply and long-term lifecycle assurance.

Supply support for SN74LVC2T45 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 over 90 years of innovation in industrial, automotive, and communications markets.

SN74LVC2T45 belongs to TI's LVC logic family, engineered for low-voltage, high-speed bidirectional translation in space- and power-constrained mixed-signal systems where voltage domain interoperability is critical.

FAQ

What voltage ranges does the SN74LVC2T45 support on VCCA and VCCB?

The SN74LVC2T45 supports independent supply voltages from 1.65 V to 5.5 V on both VCCA and VCCB. This allows translation between any combination of standard logic nodes - including 1.8 V ↔ 2.5 V, 2.5 V ↔ 3.3 V, 3.3 V ↔ 5 V, and all permutations - without external components. The device remains fully functional across this entire range, with guaranteed timing and drive strength.

How does the DIR pin function in the SN74LVC2T45?

The DIR pin in the SN74LVC2T45 controls data direction and is referenced exclusively to VCCA. When DIR = HIGH (≥ VCCA × 0.7), data flows from the A port (A1/A2) to the B port (B1/B2). When DIR = LOW (≤ VCCA × 0.3), data flows from B to A. The DIR input has low leakage (±2 µA) and supports clean edge transitions even during partial power-down via Ioff.

Does the SN74LVC2T45 support partial-power-down operation?

Yes, the SN74LVC2T45 supports partial-power-down via its Ioff feature. When either VCCA or VCCB is at 0 V, the Ioff circuitry disables all I/Os, limiting leakage current to ±2 µA per pin. This prevents back-current flow into powered-down domains - a critical requirement for battery-backed systems, automotive sleep modes, and hot-plug interfaces.

What is the maximum data rate achievable with the SN74LVC2T45?

The SN74LVC2T45 achieves up to 420 Mbps when translating from 3.3 V to 5 V, 210 Mbps when translating to 3.3 V, 140 Mbps to 2.5 V, and 75 Mbps to 1.8 V. These rates are validated across temperature (–40°C to +85°C) and supply variations, with propagation delays as low as 0.7 ns (VCCA = 5 V, VCCB = 5 V) ensuring timing margin in high-speed digital links.

Which package options are available for the SN74LVC2T45?

The SN74LVC2T45 is offered in three package variants: DCT (SM8, 8-pin, 2.95 mm × 4.00 mm), DCU (VSSOP, 8-pin, 2.00 mm × 3.10 mm), and YZP (DSBGA, 8-pin, 1.50 mm × 0.50 mm). The DCT variant - used in the SN74LVC2T45DCUTG4 - is TI's NanoFree™ wafer-chip-scale package optimized for minimal footprint, low inductance, and thermal efficiency in dense PCB layouts.