Texas Instruments SN74AVC1T45DCKT

Overview

SN74AVC1T45 from Texas Instruments is a single-bit dual-supply bus transceiver enabling bidirectional voltage translation between 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V logic domains with ±12mA drive at 3.3V, 4.6V I/O tolerance, and VCC isolation. It serves as a level-shifting interface in mixed-voltage SoC interconnects, FPGA I/O expansion, and low-power sensor hub subsystems.

For engineers reviewing the SN74AVC1T45 datasheet, SN74AVC1T45 pinout, SN74AVC1T45 application, or SN74AVC1T45 equivalent, this page delivers verified electrical specs, NanoFree™ package details, directional control timing behavior, and real-world level-shifting implementation guidance - all confirmed against TI's SCES530L production datasheet (Jan 2026 revision).

Technical Context

The SN74AVC1T45 implements a fully configurable dual-rail architecture: VCCA powers the A port and DIR input (logic-referenced to VCCA), while VCCB powers the B port. Both rails operate independently across 1.2V–3.6V, enabling asynchronous bidirectional translation without external biasing or direction latching.

Its functional mode is controlled solely by the DIR signal: high enables A→B transmission; low enables B→A transmission. The device features Ioff circuitry for partial-power-down operation and VCC isolation - if either VCCA or VCCB = GND, both ports enter high-impedance state - ensuring system-level fault containment during rail sequencing.

Key Specifications

Pinout & Package

SN74AVC1T45DCKT uses the DCK (SOT-SC70, 6-pin) package: 2.0mm × 2.1mm footprint, ultra-thin profile, and NanoFree™ die-as-package construction for minimal parasitic inductance and thermal resistance (RθJA = 211.4°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TXB0101DGSR and SN74LVC1T45DCKR, the SN74AVC1T45DCKT uniquely delivers guaranteed 500Mbps translation, VCC isolation for rail sequencing safety, and NanoFree™ packaging for high-density layouts - making it the only option for deterministic, high-speed, mixed-voltage bidirectional bridging where DIR control and fault containment are mandatory.

Availability

SN74AVC1T45DCKT is available at Aetrix Electronics and suitable for mobile sensor hubs, FPGA I/O expansion, wearable subsystems, and automotive body control modules requiring stable component supply, full production traceability, and long-term lifecycle support.

Supply support for SN74AVC1T45DCKT 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 precision analog and low-power digital solutions.

The SN74AVC1T45 belongs to TI's AVC (Advanced Very-Low-Voltage CMOS) logic family, engineered specifically for high-speed, low-voltage bidirectional level translation in space-constrained, multi-rail portable and industrial systems.

FAQ

What is the maximum supported data rate for SN74AVC1T45DCKT in a 1.8V-to-3.3V translation scenario?

The SN74AVC1T45DCKT supports up to 500Mbps when translating from 1.8V to 3.3V, as specified in Section 1 of the SCES530L datasheet. This performance is achievable under recommended operating conditions (VCCA = 1.8V ± 0.15V, VCCB = 3.3V ± 0.3V, TA = –40°C to +85°C) with 15pF load and 1ns input rise/fall time. Real-world throughput depends on PCB layout, termination, and signal integrity margins.

Does SN74AVC1T45DCKT require external pull-up resistors on the A or B I/O lines?

No, SN74AVC1T45DCKT does not require external pull-up resistors on A or B I/O lines for basic operation. Its inputs include weak internal pulldowns (per Section 5.3 footnote 3), ensuring defined logic states when externally floating. However, pull-ups may still be needed in bidirectional applications to prevent bus contention during DIR transitions - refer to Figure 8-3 and Table 8-2 in the SN74AVC1T45 datasheet for timing-safe bus hold design.

Can SN74AVC1T45DCKT operate with VCCA = 1.2V and VCCB = 3.3V simultaneously?

Yes, SN74AVC1T45DCKT is explicitly designed for asymmetric dual-supply operation, including VCCA = 1.2V and VCCB = 3.3V. Section 7.1 confirms operational capability down to 1.2V on either rail, and Table 5-6 lists switching characteristics for this exact combination (tPLH/tPHL = 3.3ns typical). The device maintains 4.6V I/O tolerance on both sides, protecting the 1.2V A port from 3.3V B-side transients.

What is the purpose of the VCC isolation feature in SN74AVC1T45DCKT?

The VCC isolation feature in SN74AVC1T45DCKT ensures that if either VCCA or VCCB is driven to GND (e.g., during power-down sequencing), both A and B ports automatically enter high-impedance state - preventing back-current flow and potential damage to powered rails. This behavior is documented in Section 1 (Features) and Section 7.3.4 of the SCES530L datasheet and is critical for safe multi-rail system power management.

Is SN74AVC1T45DCKT compatible with I²C open-drain bus topologies?

SN74AVC1T45DCKT is not recommended for standard I²C open-drain topologies because it lacks auto-direction sensing and relies on an active DIR signal. Its 3-state outputs are designed for push-pull buses (e.g., SPI, parallel GPIO). For I²C, TI recommends the TXB0101 or PCA9306 - devices with built-in bus arbitration and slew-rate control. Using SN74AVC1T45DCKT on I²C requires external direction control logic and risks bus contention if DIR timing is misaligned.