Texas Instruments SN74AXCH1T45DTQR

Overview

SN74AXCH1T45 from Texas Instruments is a single-bit dual-supply bus transceiver enabling bidirectional voltage translation between 0.65 V and 3.6 V rails, featuring tri-state outputs, bus-hold inputs, and VCC isolation. It supports up to 500-Mbps data rates (1.8 V → 3.3 V), operates from –40°C to +125°C, and draws ≤16 µA combined supply current at 125°C - ideal for low-power I/O bridging in mixed-voltage SoC interfaces.

For engineers reviewing the SN74AXCH1T45 datasheet, SN74AXCH1T45 pinout, SN74AXCH1T45 application, or SN74AXCH1T45 equivalent, this device is selected for ultra-low-quiescent-power bidirectional level shifting where supply sequencing robustness, bus-hold elimination of external resistors, and high-temperature industrial operation are critical design requirements.

Technical Context

The SN74AXCH1T45 implements a fully configurable dual-rail architecture: Port A tracks VCCA (0.65–3.6 V), Port B tracks VCCB (0.65–3.6 V), and DIR-referenced to VCCA-controls signal direction (A→B or B→A). Its bus-hold circuitry actively maintains valid logic states on unused A/B inputs without external biasing.

VCC isolation disables all I/Os into high-impedance when either VCCA or VCCB falls below 100 mV; Ioff protection limits leakage to ±12 µA during partial power-down. Glitch-free power sequencing permits arbitrary VCCA/VCCB ramp order without functional disruption.

Key Specifications

Pinout & Package

X2SON-6 package (1.00 mm × 0.80 mm, 0.35-mm pitch), ultra-compact footprint optimized for space-constrained portable and wearable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AVCH1T45DBV and TXS0101DCKR, the SN74AXCH1T45DTQR delivers the smallest footprint, guaranteed VCC isolation, and lowest high-temperature quiescent current - making it the sole option for thermally constrained, safety-critical, or ultra-low-power mixed-voltage control paths.

Availability

SN74AXCH1T45DTQR is available at Aetrix Electronics and suitable for industrial sensor hubs, automotive body control modules, and enterprise SSD power management requiring stable component supply, long-term lifecycle support, and AEC-Q200-aligned reliability.

Supply support for SN74AXCH1T45DTQR 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 delivering analog, embedded processing, and connectivity solutions with over 90 years of engineering excellence and broad industrial qualification.

The SN74AXCH1T45 belongs to TI's AXCH family of ultra-low-power configurable translators, designed specifically for energy-efficient voltage bridging in battery-powered, automotive, and high-density computing systems where space, thermal headroom, and supply robustness are limiting factors.

FAQ

What is the minimum operating voltage for SN74AXCH1T45DTQR on each supply rail?

The SN74AXCH1T45DTQR supports VCCA and VCCB down to 0.65 V independently. This enables direct interfacing with emerging sub-1-V logic families such as ARM Cortex-M0+ cores and ultra-low-power IoT MCUs. Operation below 0.65 V is not characterized and may result in undefined bus-hold behavior or increased propagation delay.

Does SN74AXCH1T45DTQR require external pullup or pulldown resistors on its A and B ports?

No - the SN74AXCH1T45DTQR integrates active bus-hold circuitry on both A and B inputs, which maintains valid logic states without external resistors. Using external biasing is explicitly discouraged in the datasheet, as it can interfere with bus-hold current thresholds and increase power consumption unnecessarily.

How does the VCC isolation feature behave in SN74AXCH1T45DTQR during power-loss scenarios?

When either VCCA or VCCB drops below 100 mV, the SN74AXCH1T45DTQR forces both A and B ports into high-impedance state immediately. This prevents back-driving of powered rails, protects downstream devices from latch-up, and ensures clean signal isolation during brownout or hot-unplug events - a key requirement in modular industrial systems.

What is the maximum data rate supported by SN74AXCH1T45DTQR, and under what conditions?

The SN74AXCH1T45DTQR supports up to 500 Mbps when translating from 1.8 V to 3.3 V, as specified in the datasheet Features section. This performance is achievable with matched trace impedance, ≤10-pF load capacitance, and proper termination - verified under controlled lab conditions with fast-edge drivers and low-noise measurement setups.

Is SN74AXCH1T45DTQR compatible with I²C or SMBus protocols?

The SN74AXCH1T45DTQR is not recommended for standard I²C or SMBus use due to its directional control (DIR pin) and lack of open-drain output structure. While it can translate static control signals on those buses, it cannot handle bidirectional data arbitration or clock stretching. For I²C, TI recommends dedicated solutions like TCA9617A or PCA9306.