Diodes Incorporated 74LVC1T45FW4-7

Overview

74LVC1T45FW4-7 from Diodes Incorporated is a single-bit, dual-supply translating transceiver with 3-state outputs, designed for bidirectional voltage-level translation between independent 1.65V–5.5V domains. It features A/B I/O pins referenced to VCCA/VCCB respectively, DIR-controlled directionality, ±24mA drive at 3.3V, and I_OFF protection enabling partial power-down isolation in portable logic interconnects such as USB-C PD controllers and multi-rail SoC interfaces.

For engineers reviewing the 74LVC1T45FW4-7 datasheet, 74LVC1T45FW4-7 pinout, 74LVC1T45FW4-7 application, or 74LVC1T45FW4-7 equivalent, this device is selected for low-voltage bidirectional signal bridging where rail independence, sub-10ns propagation delay, and zero-V_CC high-impedance state are required - not for clock distribution, analog switching, or power regulation.

Technical Context

The 74LVC1T45FW4-7 implements a CMOS-based dual-supply transceiver architecture with separate VCCA and VCCB supplies, allowing asymmetric voltage translation (e.g., 1.8V ↔ 3.3V). Direction control is referenced solely to VCCA, ensuring deterministic logic interpretation regardless of VCCB level.

Its I_OFF circuitry activates when either supply drops to 0V, clamping leakage to ±2μA while maintaining up to 5.5V electrical isolation on A/B pins - a critical feature for hot-plug and battery-backed subsystems requiring no backfeed current path during power sequencing.

Key Specifications

Pinout & Package

X2-DFN1010-6 package: 1.0mm × 1.0mm, 0.35mm height, 0.35mm pitch, bottom-side thermal pad, RoHS-compliant lead-free construction.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1T45DCKR, the 74LVC1T45FW4-7 offers 55% smaller footprint and 2.2× better thermal resistance, while FXMA108MRMT eliminates DIR routing but sacrifices 5.5V tolerance and increases static power - making the FW4 variant optimal for space-constrained, mixed-voltage, direction-controlled links.

Availability

74LVC1T45FW4-7 is available at Aetrix Electronics and suitable for USB-C PD interface design, FPGA configuration bus bridging, and industrial sensor hub interconnect requiring stable component supply across automotive, computing, and consumer electronics programs.

Supply support for 74LVC1T45FW4-7 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

Diodes Incorporated is a global semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for power management, signal integrity, and connectivity applications.

The 74LVC1T45 belongs to the LVC logic family, engineered for low-voltage, high-speed translation in portable and multi-rail systems where rail independence, minimal footprint, and robust power-down behavior are essential.

FAQ

What is the maximum allowable voltage difference between VCCA and VCCB?

The 74LVC1T45FW4-7 permits any combination within its 1.65V–5.5V range per supply, including VCCA = 1.65V and VCCB = 5.5V simultaneously. No differential limit is specified - only absolute min/max per pin. This enables extreme translations like 1.8V microcontroller ↔ 5V legacy peripheral without external components.

Can the DIR pin be left floating during operation?

No. The DIR pin must be actively driven to a valid logic level referenced to VCCA. Floating DIR causes undefined A/B directionality and may increase ICC due to input stage contention. Per datasheet Note 6, unused inputs should be tied to VCCA or GND using ≤10kΩ resistors to ensure deterministic operation.

Does the device support hot insertion when one supply is powered and the other is off?

Yes. When either VCCA or VCCB is at 0V, the I_OFF feature forces all outputs into high-impedance state with ±2μA leakage, preventing backfeed and allowing safe hot insertion into live systems - a key requirement for modular computing and docking station designs.

What is the recommended PCB layout for thermal performance in the X2-DFN1010-6 package?

Use a minimum 1.0mm² exposed copper thermal pad connected to internal ground planes via ≥4 thermal vias (0.3mm diameter, 0.6mm spacing). Maintain solder mask opening matching pad size and apply 100% stencil coverage for optimal thermal conduction - achieving θ_JA ≈ 430°C/W per datasheet, critical for sustained 24mA output operation.