Texas Instruments SN74AVC4T245RSVR

Overview

SN74AVC4T245 from Texas Instruments is a 4-bit dual-supply noninverting bus transceiver enabling bidirectional voltage translation between 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V logic domains. It features independent VCCA (1.2–3.6V) and VCCB (1.2–3.6V) rails, 4.6V I/O tolerance, Ioff partial-power-down support, and up to 380Mbps data rate (1.8V→3.3V). It is used in low-voltage interconnects between processors and peripherals in portable electronics.

For engineers reviewing the SN74AVC4T245 datasheet, SN74AVC4T245 pinout, SN74AVC4T245 application, or SN74AVC4T245 equivalent, key selection criteria include dual-rail configurability, 3-state output control per channel, VCCA-referenced DIR/OE inputs, Ioff-enabled isolation during power sequencing, and verified 380Mbps translation performance at 1.8V-to-3.3V.

Technical Context

The SN74AVC4T245 implements two independent 2-bit bidirectional channels, each with dedicated DIR and OE controls referenced to VCCA. Its dual-rail architecture decouples A-port (VCCA-tracked) and B-port (VCCB-tracked) logic levels, enabling asynchronous translation without clocking or direction latching.

Each channel supports four functional states: A→B transmission (DIR=H, OE=L), B→A transmission (DIR=L, OE=L), high-impedance isolation (OE=H), and powered-down isolation (Ioff active when either VCCA or VCCB = 0V). Input circuits remain always-active to prevent floating-node leakage.

Key Specifications

Pinout & Package

SN74AVC4T245RSVR uses a 16-pin UQFN package (2.6mm × 1.8mm) with wettable flanks and thermal pad. Pin numbering follows standard top-view orientation with pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC4T245PW and TXS0104EPWR, the SN74AVC4T245 provides unique dual-rail flexibility, highest data rate (380Mbps), and robust Ioff/VCC isolation - making it the only choice for mixed-voltage, high-speed, and hot-plug-critical designs.

Availability

SN74AVC4T245RSVR is available at Aetrix Electronics and suitable for mobile processor interfacing, industrial sensor hubs, automotive infotainment backplanes, and enterprise SSD controller interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AVC4T245RSVR 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 specializing in analog and embedded processing technologies, with leadership in precision analog, power management, and interface solutions.

The SN74AVC4T245 belongs to TI's AVC (Advanced Very-low-voltage CMOS) logic family, designed specifically for ultra-low-voltage bidirectional translation in space-constrained, power-sensitive applications such as portable electronics and multi-rail embedded systems.

FAQ

What voltage ranges does the SN74AVC4T245 support on its A and B ports?

The SN74AVC4T245 supports independent supply voltages from 1.2V to 3.6V on both VCCA (A port and control inputs) and VCCB (B port). This enables translation between any combination of 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V logic domains. The device remains fully operational down to 1.2V on either rail, with optimized performance between 1.4V and 3.6V.

How does the SN74AVC4T245 handle power sequencing when VCCA and VCCB ramp at different times?

The SN74AVC4T245 incorporates VCC isolation: if either VCCA or VCCB is at GND, both A and B ports automatically enter high-impedance mode. Additionally, its Ioff circuitry disables outputs during partial power-down, preventing back-current flow. To ensure safe startup, tie OE to VCCA via a pullup resistor so outputs remain disabled until both supplies stabilize.

Can the SN74AVC4T245 replace discrete MOSFET-based level shifters in high-speed designs?

Yes - the SN74AVC4T245 replaces discrete MOSFET translators in designs requiring >100Mbps operation. With verified 380Mbps performance (1.8V→3.3V), sub-3.6ns propagation delay, and matched rise/fall times, it maintains signal integrity in USB 2.0, SDIO, and parallel memory interfaces where discrete solutions introduce skew and layout complexity.

What is the function of the DIR and OE pins, and how are they referenced?

Each DIR pin (1DIR, 2DIR) controls data direction per 2-bit channel and is referenced to VCCA. Each OE pin (1OE, 2OE) enables/disables the corresponding channel's outputs and is also VCCA-referenced. This ensures consistent threshold behavior regardless of VCCB level - a key advantage over single-supply translators when VCCB differs significantly from VCCA.

Does the SN74AVC4T245 require external pullup/pulldown resistors on data lines?

No - the SN74AVC4T245 has no internal pullups or pulldowns on A/B I/O pins. However, TI recommends tying OE to VCCA via an external pullup resistor (value determined by driver sink capability) to ensure outputs remain in high-impedance during power-up/power-down. Unused DIR/OE inputs must be actively driven to VCCA or GND to prevent excess ICCZ.