Texas Instruments SN74AVCH1T45YZPR

Overview

SN74AVCH1T45 from Texas Instruments is a single-bit dual-supply noninverting bus transceiver enabling bidirectional voltage translation between 1.2V–3.6V rails (e.g., 1.8V ↔ 3.3V), with 3-state outputs, bus-hold on data inputs, and I_off partial-power-down support. It operates across –40°C to +85°C and delivers up to 500Mbps data rate in 1.8V-to-3.3V translation.

For engineers reviewing the SN74AVCH1T45 datasheet, SN74AVCH1T45 pinout, SN74AVCH1T45 application, or SN74AVCH1T45 equivalent, key selection criteria include configurable dual-rail supply ranges (VCCA/VCCB = 1.2V–3.6V), DIR input referenced to VCCA, 4.6V I/O tolerance, VCC isolation behavior, and NanoFree™ DSBGA package compatibility with space-constrained portable electronics designs.

Technical Context

The SN74AVCH1T45 implements a fully configurable dual-rail architecture where A-port logic levels track VCCA (1.2V–3.6V) and B-port levels track VCCB (1.2V–3.6V), enabling asynchronous bidirectional translation without external biasing. The DIR control input is strictly referenced to VCCA, defining directionality: high enables A→B, low enables B→A.

VCC isolation forces both ports into high-impedance state if either VCCA or VCCB is at GND, while bus-hold circuitry actively maintains valid logic states on undriven A/B inputs-eliminating need for external pull resistors. I_off protection limits current backflow during partial power-down, supporting robust system-level power sequencing.

Key Specifications

Pinout & Package

SN74AVCH1T45 YZP package is a 6-pin DSBGA (1.50mm × 0.90mm) with bottom-side ball layout. Pin mapping is validated per TI SCES598F Rev. April 2024, Figure 5-2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1T45DBVR and TXS0101DCKR, the SN74AVCH1T45 uniquely combines independent dual-rail supplies, VCC isolation, bus-hold, and I_off-making it the only option for robust, space-constrained, multi-voltage system interfaces requiring hardware-level fault containment.

Availability

SN74AVCH1T45 is available at Aetrix Electronics and suitable for mobile processor interfacing, low-power sensor hub integration, industrial PLC I/O expansion, and enterprise SSD controller interface applications requiring stable component supply, long-term lifecycle support, and consistent DSBGA package availability.

Supply support for SN74AVCH1T45 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 for industrial, automotive, and personal electronics markets.

The SN74AVCH1T45 belongs to TI's AVC logic family, engineered specifically for ultra-low-voltage, high-speed bidirectional translation in space- and power-constrained portable systems.

FAQ

What voltage ranges does the SN74AVCH1T45 support on VCCA and VCCB?

The SN74AVCH1T45 supports independent supply voltages from 1.2V to 3.6V on both VCCA and VCCB. This enables translation between any combination of standard logic domains-including 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V-without external components. Operation outside this range violates absolute maximum ratings and may cause permanent damage to the SN74AVCH1T45.

How does the DIR input function in the SN74AVCH1T45?

The DIR input on the SN74AVCH1T45 is referenced exclusively to VCCA and controls data direction: a high logic level enables transmission from Port A to Port B, while a low level enables transmission from Port B to Port A. Its VIH/VIL thresholds scale with VCCA (e.g., VIH = VCCA × 0.65 at 1.2V–1.95V), ensuring reliable operation across all supported VCCA voltages. This behavior is intrinsic to the SN74AVCH1T45's architecture.

Does the SN74AVCH1T45 require external pull-up or pull-down resistors?

No, the SN74AVCH1T45 integrates active bus-hold circuitry on both A and B ports, which maintains valid logic states on undriven or floating inputs. TI explicitly advises against using external pull resistors with bus-hold enabled, as they conflict with the internal sustaining current (IBHL/IBHH). This feature directly reduces BOM count and simplifies layout for the SN74AVCH1T45.

What happens to the outputs of the SN74AVCH1T45 when VCCA or VCCB is at GND?

When either VCCA or VCCB is at GND, the SN74AVCH1T45 activates its VCC isolation feature, forcing both A and B ports into a high-impedance (3-state) condition regardless of DIR or input states. This prevents bus contention and back-current flow during power sequencing, hot-swap events, or fault conditions-ensuring system-level robustness unique to the SN74AVCH1T45 among single-bit translators.

Is the SN74AVCH1T45 compatible with the NanoFree™ DSBGA package footprint?

Yes, the SN74AVCH1T45 YZPR variant uses Texas Instruments' NanoFree™ DSBGA package (1.50mm × 0.90mm, 6-ball array), where the silicon die serves as the package substrate. This eliminates wire bonds and mold compound, achieving the smallest possible footprint and thermal resistance (R_θJB = 51°C/W) for the SN74AVCH1T45-critical for ultra-thin mobile and wearable designs.