Texas Instruments 74AVCH1T45DBVTG4

Overview

74AVCH1T45DBVTG4 from Texas Instruments is a single-bit, dual-supply noninverting bus transceiver enabling bidirectional voltage translation between 1.2V–3.6V domains (e.g., 1.8V ↔ 3.3V). It features independent VCCA and VCCB rails, bus-hold on A/B I/Os, Ioff partial-power-down support, and 4.6V I/O tolerance. It serves in low-voltage interconnects between microcontrollers and peripherals in space-constrained portable electronics.

For engineers reviewing the 74AVCH1T45DBVTG4 datasheet, 74AVCH1T45DBVTG4 pinout, 74AVCH1T45DBVTG4 application, or 74AVCH1T45DBVTG4 equivalent, key selection criteria include configurable dual-rail operation, DIR-referenced-to-VCCA control logic, guaranteed 2.8 ns max propagation delay (3.3V→3.3V), 2000V HBM ESD rating, and SOT-23-6 (DBV) package compatibility with NanoFree™ footprint.

Technical Context

The 74AVCH1T45DBVTG4 implements a fully configurable dual-rail architecture where A-port signals track VCCA (1.2V–3.6V) and B-port signals track VCCB (1.2V–3.6V), enabling asynchronous bidirectional level shifting without external biasing. The DIR input is referenced solely to VCCA, decoupling direction control from B-side supply conditions.

Its bus-hold circuitry actively sustains undriven A/B inputs at valid logic levels (IBHL ≥25 µA low, IBHH ≥−25 µA high), eliminating external pull resistors. VCC isolation forces outputs into high-Z if either VCCA or VCCB = GND, while Ioff limits leakage to ±5 µA when either supply is off.

Key Specifications

Pinout & Package

SOT-23-6 (DBV) package: 2.90 mm × 1.60 mm, ultra-small footprint compatible with NanoFree™ packaging technology.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1T45DBVR and TXS0101DCKR, the 74AVCH1T45DBVTG4 uniquely combines bus-hold, 4.6V tolerance, and sub-3 ns delay in a 6-pin SOT-23 - making it optimal for high-density, low-power, mixed-voltage microcontroller interconnects where layout area and BOM simplicity are critical.

Availability

74AVCH1T45DBVTG4 is available at Aetrix Electronics and suitable for mobile SoC interconnect, industrial sensor hub, wearable battery management, enterprise SSD controller interface, and IoT edge node applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 74AVCH1T45DBVTG4 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 low-voltage, high-speed bidirectional level translation in space- and power-constrained portable and embedded systems.

FAQ

What voltage ranges does the 74AVCH1T45DBVTG4 support on its VCCA and VCCB pins?

The 74AVCH1T45DBVTG4 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 domains - including 1.2V ↔ 1.5V, 1.8V ↔ 2.5V, and 1.8V ↔ 3.3V - without external components or configuration. The DIR input is referenced exclusively to VCCA, ensuring reliable direction control regardless of VCCB level.

Does the 74AVCH1T45DBVTG4 require external pull-up or pull-down resistors on its A or B I/O pins?

No, the 74AVCH1T45DBVTG4 integrates active bus-hold circuitry on both A and B I/O pins, which maintains undriven inputs at valid logic states. At 1.2V supply, it provides ≥25 µA low-sustaining current (IBHL) and ≥−25 µA high-sustaining current (IBHH), eliminating the need for external pull resistors and reducing PCB area and BOM cost. TI explicitly advises against adding external resistors when bus-hold is enabled.

How does the 74AVCH1T45DBVTG4 behave when one supply rail is powered down?

When either VCCA or VCCB is at GND, the 74AVCH1T45DBVTG4 activates VCC isolation: all outputs enter high-impedance state to prevent contention or back-current flow. Simultaneously, Ioff circuitry limits leakage to ±5 µA per port, protecting powered sections. Bus-hold remains active on the powered side, preserving signal integrity during partial-power-down sequences common in battery-powered and hot-swap systems.

What is the maximum data rate supported by the 74AVCH1T45DBVTG4 in a 1.8V-to-3.3V translation scenario?

In 1.8V-to-3.3V translation, the 74AVCH1T45DBVTG4 supports up to 500 Mbps, as specified in its datasheet. This is enabled by sub-3 ns typical propagation delay (e.g., 2.4 ns A→B at VCCA=1.8V, VCCB=3.3V) and low 6 pF I/O capacitance. Real-world achievable rate depends on load capacitance, trace impedance, and signal integrity margins - but the device is characterized and rated for 500 Mbps under defined conditions.

Is the 74AVCH1T45DBVTG4 pin-compatible with other single-bit transceivers in TI's portfolio?

The 74AVCH1T45DBVTG4 uses the standard SOT-23-6 (DBV) footprint and shares identical pinout with SN74LVC1T45DBVR and SN74AXC1T45DBVR. However, electrical behavior differs: the 74AVCH1T45DBVTG4 includes bus-hold and tighter propagation delay specs, while LVC and AXC variants offer different VCC ranges and drive strengths. Pin-for-pin replacement is mechanically possible but requires validation of timing, leakage, and feature compatibility in the target design.