Texas Instruments SN74LVC1T45DCKRE4

Overview

SN74LVC1T45 from Texas Instruments is a single-bit dual-supply bus transceiver enabling bidirectional voltage-level translation between 1.65V–5.5V domains, with 3-state outputs, ±24mA drive at 3.3V, 4µA max ICC, and VCC isolation. It serves in low-pin-count I/O bridging between mixed-voltage subsystems such as MCU peripherals and legacy interfaces.

For engineers reviewing the SN74LVC1T45 datasheet, SN74LVC1T45 pinout, SN74LVC1T45 application, or SN74LVC1T45 equivalent, key selection criteria include configurable dual-rail operation, Ioff partial-power-down support, DIR-controlled directionality, high-speed translation up to 420Mbps (3.3V→5V), and SC70-6 package compatibility with space-constrained PCB layouts.

Technical Context

The SN74LVC1T45 implements asynchronous bidirectional translation using separate VCCA- and VCCB-referenced I/O rails, where DIR (referenced to VCCA) selects data flow direction: high enables A→B, low enables B→A. Input circuits remain active on both ports regardless of DIR state, requiring defined logic levels to avoid excess ICCZ.

VCC isolation ensures both A and B ports enter high-impedance when either VCCA or VCCB = GND; Ioff circuitry limits leakage to ±2µA over –40°C to +85°C during power-down, preventing backflow. Propagation delays range from 0.5ns to 17.7ns depending on rail combinations (e.g., tPLH A→B = 0.5ns min at VCCA=5V/VCCB=1.8V).

Key Specifications

Pinout & Package

SN74LVC1T45DCKRE4 uses the SC70-6 (DCK) package: 2.0mm × 2.1mm, 0.65mm pitch, 6-pin surface-mount with exposed pad not present. Pin numbering follows TI standard top-view orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage translation applications.

Compared with TXB0101RGYR and 74AVC1T45GW,125, SN74LVC1T45DCKRE4 uniquely delivers 1.65V–5.5V dual-rail translation with VCC isolation, Ioff, and 420Mbps performance-making it the only option supporting 5V legacy integration and robust partial-power-down in space-constrained designs.

Availability

SN74LVC1T45DCKRE4 is available at Aetrix Electronics and suitable for industrial sensor interfaces, wearable MCU expansion, legacy peripheral bridging, and automotive body control modules requiring stable component supply and long-term production continuity.

Supply support for SN74LVC1T45DCKRE4 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 decades of expertise in logic and interface ICs.

The SN74LVC1T45 belongs to TI's LVC logic family, designed specifically for low-voltage, high-speed bidirectional translation in space- and power-constrained embedded systems across industrial, automotive, and consumer markets.

FAQ

What voltage ranges does the SN74LVC1T45DCKRE4 support on its VCCA and VCCB rails?

The SN74LVC1T45DCKRE4 supports independent 1.65V to 5.5V operation on both VCCA and VCCB rails. This allows translation between any combination of common logic voltages-including 1.8V, 2.5V, 3.3V, and 5V-without external components. The DIR input is referenced to VCCA, and both I/O ports adapt their thresholds and output levels to their respective supply rails.

How does the DIR pin control data direction in the SN74LVC1T45DCKRE4?

In the SN74LVC1T45DCKRE4, the DIR pin is a VCCA-referenced digital input: a logic HIGH enables data transmission from the A port to the B port, while a logic LOW enables transmission from the B port to the A port. The A and B ports remain electrically active regardless of DIR state, so undefined inputs must be avoided to prevent excessive ICCZ current.

Does the SN74LVC1T45DCKRE4 support partial-power-down operation?

Yes, the SN74LVC1T45DCKRE4 supports partial-power-down via its Ioff feature. When either VCCA or VCCB is at GND, both ports enter high-impedance, and Ioff limits leakage to ±2µA over –40°C to +85°C. This prevents damaging current backflow and ensures safe operation in multi-rail systems with staggered power sequencing.

What is the maximum data rate achievable with the SN74LVC1T45DCKRE4?

The SN74LVC1T45DCKRE4 achieves up to 420Mbps when translating from 3.3V to 5V. Performance varies with rail combinations: 210Mbps (to 3.3V), 140Mbps (to 2.5V), and 75Mbps (to 1.8V). These rates reflect guaranteed timing under recommended operating conditions and are validated across the full industrial temperature range.

Which package type is used by the SN74LVC1T45DCKRE4, and what are its key mechanical features?

The SN74LVC1T45DCKRE4 uses the SC70-6 (DCK) package: a 2.0mm × 2.1mm surface-mount outline with 0.65mm pin pitch and no exposed thermal pad. It belongs to TI's NanoFree™ technology, where the silicon die serves as the package-reducing footprint by ~40% versus SOT-23-6 and enabling ultra-dense PCB layouts.