Texas Instruments 74AVCH1T45DBVRE4

Overview

74AVCH1T45DBVRE4 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 circuitry, 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 74AVCH1T45DBVRE4 datasheet, 74AVCH1T45DBVRE4 pinout, 74AVCH1T45DBVRE4 application, or 74AVCH1T45DBVRE4 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 SOT-23-6 (DBV) package compatibility with space-constrained PCB layouts.

Technical Context

The 74AVCH1T45DBVRE4 implements a fully configurable dual-rail architecture where A-port I/Os track VCCA (1.2V–3.6V) and B-port I/Os track VCCB (1.2V–3.6V), enabling asynchronous bidirectional translation without direction-dependent voltage constraints. The DIR control input is strictly referenced to VCCA, not VCCB, defining signal flow directionality.

It integrates bus-hold circuitry on both A and B ports to maintain valid logic states on undriven inputs, eliminating external pull resistors. VCC isolation forces outputs into high-impedance when either VCCA or VCCB is at GND, while Ioff limits leakage current (<5µA) during partial power-down-critical for system-level power sequencing.

Key Specifications

Pinout & Package

74AVCH1T45DBVRE4 is packaged in a 6-pin SOT-23 (DBV) case measuring 2.90mm × 1.60mm, optimized for high-density routing and automated placement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1T45DBVR and TXS0101DCKR, the 74AVCH1T45DBVRE4 uniquely combines bus-hold, Ioff, VCC isolation, and 500Mbps performance in a single SOT-23-6 package-making it optimal for robust, space-constrained, mixed-voltage designs requiring deterministic direction control.

Availability

74AVCH1T45DBVRE4 is available at Aetrix Electronics and suitable for mobile SoC interfacing, industrial sensor hubs, automotive body control, and enterprise SSD controller applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 74AVCH1T45DBVRE4 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 and embedded processing solutions, with over 90 years of innovation in power management, signal chain, and logic technologies.

The SN74AVCH1T45 product line targets low-voltage, space-constrained systems requiring reliable bidirectional level translation-designed specifically for portable electronics, industrial IoT nodes, and automotive sub-systems operating across multiple voltage domains.

FAQ

What voltage ranges does the 74AVCH1T45DBVRE4 support on its VCCA and VCCB supplies?

The 74AVCH1T45DBVRE4 supports independent supply voltages from 1.2V to 3.6V on both VCCA and VCCB pins. This allows translation between any combination of standard low-voltage rails-including 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V-without external components or configuration. Operation outside this range violates absolute maximum ratings and may cause permanent damage.

How does the DIR input function in the 74AVCH1T45DBVRE4, and what is its voltage reference?

The DIR input in the 74AVCH1T45DBVRE4 determines data flow direction: logic high enables transmission from A to B, and logic low enables transmission from B to A. Critically, DIR is referenced exclusively to VCCA-not VCCB-so its VIH and VIL thresholds scale with the A-side supply voltage. This ensures correct interpretation even when VCCA and VCCB differ significantly.

Does the 74AVCH1T45DBVRE4 require external pull-up or pull-down resistors on its A and B ports?

No, the 74AVCH1T45DBVRE4 includes 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 this feature. Bus-hold current ranges from ±25µA to ±100µA depending on VCCA, providing sufficient drive to sustain logic levels without added components.

What happens to the outputs of the 74AVCH1T45DBVRE4 when either VCCA or VCCB is powered down to 0V?

When either VCCA or VCCB is at GND, the 74AVCH1T45DBVRE4 activates its VCC isolation feature: all outputs (A and B) automatically enter a high-impedance state. This prevents bus contention and back-current flow. Additionally, the bus-hold circuitry remains active on the powered-up side, preserving valid logic states on that port's inputs during asymmetric power sequencing.

What is the maximum data rate supported by the 74AVCH1T45DBVRE4, and under what conditions is it achieved?

The 74AVCH1T45DBVRE4 achieves a maximum data rate of 500Mbps under 1.8V-to-3.3V translation conditions. 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 guaranteed timing margins under recommended operating conditions and are validated per TI's switching characteristics tables.