Texas Instruments 74AVCH1T45DCKTG4

Overview

74AVCH1T45DCKTG4 from Texas Instruments is a single-bit dual-supply bus transceiver enabling bidirectional voltage translation between 1.2V–3.6V domains (e.g., 1.8V ↔ 3.3V), with 3-state outputs, bus-hold on data inputs, VCC isolation, and Ioff 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 74AVCH1T45DCKTG4 datasheet, 74AVCH1T45DCKTG4 pinout, 74AVCH1T45DCKTG4 application, or 74AVCH1T45DCKTG4 equivalent, key selection criteria include dual-rail supply flexibility (VCCA/VCCB = 1.2–3.6V), DIR input referenced to VCCA, 4.6V I/O tolerance, bus-hold elimination of external resistors, and SC70-6 package compatibility with space-constrained PCB layouts.

Technical Context

The 74AVCH1T45DCKTG4 implements a noninverting, direction-controlled level-shifting architecture where DIR determines signal flow: high enables A→B translation, low enables B→A. Its dual-rail design decouples A-port logic (VCCA-referenced) from B-port logic (VCCB-referenced), supporting asymmetric voltage translation without external components.

Bus-hold circuitry actively maintains valid logic states on undriven A/B inputs, eliminating need for pullup/pulldown resistors. VCC isolation forces outputs into high-impedance when either VCCA or VCCB is at GND, while Ioff limits leakage current during partial power-down-critical for system-level power sequencing in portable and industrial electronics.

Key Specifications

Pinout & Package

74AVCH1T45DCKTG4 is packaged in a 6-pin SC70 (DCK) package measuring 2.00mm × 1.25mm, optimized for ultra-compact board space and thermal performance (RθJA = 239.9°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1T45DCKR and TXS0101DCKR, the 74AVCH1T45DCKTG4 uniquely combines dual-rail independence, VCC isolation, bus-hold, and Ioff - making it the only option for robust, direction-controlled, mixed-voltage translation in space-constrained industrial and portable designs.

Availability

74AVCH1T45DCKTG4 is available at Aetrix Electronics and suitable for industrial sensor interfaces, wearable power sequencing, and automotive infotainment subsystems requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for 74AVCH1T45DCKTG4 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 product line targets low-voltage, space-constrained system interfacing - specifically designed to simplify voltage translation between heterogeneous logic domains in portable, industrial, and automotive electronics.

FAQ

What voltage ranges does the 74AVCH1T45DCKTG4 support on its VCCA and VCCB supplies?

The 74AVCH1T45DCKTG4 supports independent supply voltages from 1.2V to 3.6V on both VCCA and VCCB. This enables translation between any combination of common low-voltage nodes - including 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V - without external components. The DIR input is referenced solely to VCCA, and all A-port signals track VCCA, while B-port signals track VCCB.

How does the bus-hold feature in the 74AVCH1T45DCKTG4 eliminate the need for external resistors?

The 74AVCH1T45DCKTG4 integrates active bus-hold circuitry on both A and B I/O pins, providing ±25μA to ±100μA sustaining current depending on supply voltage. This holds unused or undriven inputs at valid logic levels, removing the need for external pullup or pulldown resistors. TI explicitly advises against using external resistors with this feature, as they may interfere with bus-hold operation and increase power consumption.

What is the role of VCC isolation in the 74AVCH1T45DCKTG4, and when does it activate?

VCC isolation in the 74AVCH1T45DCKTG4 forces all outputs into a high-impedance state whenever either VCCA or VCCB is at GND - even if the other supply is active. This prevents back-driving, latch-up, or unintended current flow during power-up/down sequencing, hot-swap events, or fault conditions. Bus-hold remains active on the powered side, preserving signal integrity on live rails.

Does the 74AVCH1T45DCKTG4 support partial-power-down operation, and how is it implemented?

Yes, the 74AVCH1T45DCKTG4 supports partial-power-down via its Ioff feature. When either VCCA or VCCB is at 0V, the Ioff circuitry disables all outputs and limits input/output leakage to ±5μA maximum. This protects powered domains from back-current and enables safe power gating in battery-operated or modular systems - a critical capability not present in standard LVC-family translators.

What is the maximum data rate achievable with the 74AVCH1T45DCKTG4, and under what conditions?

The 74AVCH1T45DCKTG4 achieves up to 500Mbps in 1.8V-to-3.3V translation mode. Lower rates apply for other combinations: 320Mbps for <1.8V-to-3.3V or 1.8V/2.5V translation, 280Mbps for 1.5V translation, and 240Mbps for 1.2V translation. These values reflect typical performance under recommended operating conditions and assume proper signal integrity layout (e.g., controlled impedance, minimized capacitance).