Texas Instruments SN74AXCH1T45DRY2

Overview

SN74AXCH1T45 from Texas Instruments is a single-bit dual-supply bus transceiver with configurable voltage translation, tri-state outputs, and bus-hold inputs. It operates with VCCA and VCCB independently adjustable from 0.65 V to 3.6 V, supports –40°C to +125°C operation, delivers up to 500-Mbps data rate (1.8 V → 3.3 V), and features VCC isolation and Ioff partial-power-down capability. It enables level-shifting between disparate logic domains in low-power portable and industrial interface circuits.

For engineers reviewing the SN74AXCH1T45 datasheet, SN74AXCH1T45 pinout, SN74AXCH1T45 application, or SN74AXCH1T45 equivalent, this page provides verified electrical specifications, directional control behavior, thermal metrics for SON-6 packaging, bus-hold current thresholds, and real-world timing performance across voltage combinations - all critical for signal integrity validation and power-aware PCB layout.

Technical Context

The SN74AXCH1T45 implements a noninverting bidirectional data path controlled by a DIR input referenced to VCCA, enabling A→B or B→A translation depending on DIR logic state. Its dual-rail architecture allows independent supply configuration per port, supporting asymmetric voltage translation such as 0.8 V ↔ 1.8 V or 1.2 V ↔ 3.3 V without external biasing.

Glitch-free power sequencing ensures robustness during staggered VCCA/VCCB ramp-up/down, while VCC isolation disables both I/Os when either supply drops below 100 mV. Bus-hold circuitry actively maintains valid logic states on undriven A/B inputs, eliminating need for external pull resistors and reducing BOM count and board space.

Key Specifications

Pinout & Package

SN74AXCH1T45DRY uses a 6-pin SON package (1.40 mm × 1.00 mm, 0.5-mm pitch) optimized for space-constrained portable designs. The package features wettable flanks for automated optical inspection (AOI) and exposes the die pad to GND for improved thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AVCH1T45DBV and TXS0101DCKR, the SN74AXCH1T45DRY offers superior thermal performance in minimal area, guaranteed VCC isolation for fault-tolerant designs, and tighter Ioff specification - making it optimal for space- and reliability-constrained embedded systems.

Availability

SN74AXCH1T45DRY is available at Aetrix Electronics and suitable for mobile processor interface, industrial sensor hub, automotive body control module, and enterprise SSD power sequencing requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for SN74AXCH1T45DRY 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 company delivering analog and embedded processing solutions for industrial, automotive, personal electronics, and communications markets.

The SN74AXCH1T45 belongs to TI's AXCH family of ultra-low-power configurable translators, designed specifically for energy-efficient voltage-domain bridging in battery-powered and thermally constrained edge devices.

FAQ

What is the minimum operating voltage for SN74AXCH1T45DRY on each supply rail?

The SN74AXCH1T45DRY supports VCCA and VCCB down to 0.65 V each, enabling compatibility with sub-1V logic families used in advanced mobile and AI processors. This minimum is specified across the full –40°C to +125°C temperature range and validated per JEDEC JESD8-12E.

How does the DIR pin function in SN74AXCH1T45DRY, and what voltage domain references it?

The DIR pin in SN74AXCH1T45DRY determines data direction: HIGH enables A→B translation, LOW enables B→A. It is referenced exclusively to VCCA, meaning its logic thresholds scale with VCCA - e.g., at VCCA = 0.8 V, VIH ≈ 0.56 V and VIL ≈ 0.24 V - ensuring robust switching across all supported supply voltages.

Does SN74AXCH1T45DRY require external pull-up or pull-down resistors on its A and B ports?

No, SN74AXCH1T45DRY integrates active bus-hold circuitry on both A and B ports, which maintains undriven inputs at valid logic levels without external resistors. Using external pull components is explicitly discouraged in the datasheet as it may interfere with bus-hold current thresholds and increase power consumption.

What happens to the I/Os of SN74AXCH1T45DRY if one supply rail collapses during operation?

If either VCCA or VCCB drops below 100 mV, the VCC isolation feature in SN74AXCH1T45DRY forces both A and B ports into high-impedance state immediately. This prevents back-driving, current leakage, or undefined logic states - a critical safety mechanism in multi-rail systems experiencing brownout or hot-swap events.

Can SN74AXCH1T45DRY operate with only one supply rail powered?

Yes - SN74AXCH1T45DRY supports partial-power-down operation via its Ioff protection. When either VCCA or VCCB is at 0 V while the other is powered, Ioff limits current to ±12 µA maximum, allowing safe operation in asymmetric power states common in modular or hot-pluggable systems.