Texas Instruments SN74AVCH8T245PWR

Overview

SN74AVCH8T245 from Texas Instruments is an 8-bit dual-supply noninverting bus transceiver enabling bidirectional voltage translation between 1.2V–3.6V domains (e.g., A-port at 1.8V ↔ B-port at 3.3V), with 3-state outputs, bus-hold circuitry, and Ioff partial-power-down support. It operates across –40°C to +85°C and delivers up to 320Mbps data rate when both supplies ≥1.8V.

For engineers reviewing the SN74AVCH8T245 datasheet, SN74AVCH8T245 pinout, SN74AVCH8T245 application, or SN74AVCH8T245 equivalent, key selection criteria include dual-rail supply flexibility (VCCA/VCCB = 1.2–3.6V), 4.6-V I/O tolerance, VCC isolation, and guaranteed 3-state behavior during power sequencing via OE referenced to VCCA.

Technical Context

The SN74AVCH8T245 implements a fully configurable dual-rail architecture where DIR and OE inputs are referenced exclusively to VCCA, while A-port I/Os track VCCA and B-port I/Os track VCCB - enabling asymmetric voltage translation without external level shifters. Its bus-hold circuitry actively sustains undriven inputs at valid logic levels, eliminating need for external pull resistors.

VCC isolation ensures outputs enter high-impedance state if either VCCA or VCCB is at GND, and Ioff protection prevents backflow current during partial power-down. The device supports asynchronous bidirectional data flow controlled solely by DIR polarity and OE enable state, with propagation delays as low as 0.5ns (typ) under optimal supply conditions.

Key Specifications

Pinout & Package

Packaged in TSSOP-24 (PW), this 7.8 mm × 6.4 mm surface-mount IC features dual power rails (VCCA, VCCB), direction control (DIR), output enable (OE), eight bidirectional A-port pins (A1–A8), eight bidirectional B-port pins (B1–B8), and three ground terminals (GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC8T245PWR and TXB0108PWR, the SN74AVCH8T245 provides deterministic bidirectional control via DIR, higher speed, stronger drive, and guaranteed VCC isolation - making it optimal for high-reliability, mixed-voltage, timing-critical bus interfaces.

Availability

SN74AVCH8T245 is available at Aetrix Electronics and suitable for industrial PLC backplanes, enterprise SSD controllers, telecom baseband processors, and personal electronics battery management systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for SN74AVCH8T245 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 consumer markets.

The SN74AVCH8T245 belongs to TI's AVC logic family, engineered specifically for low-voltage, mixed-domain system interconnect - emphasizing voltage translation fidelity, power sequencing safety, and high-speed signal integrity in space-constrained designs.

FAQ

What voltage ranges does the SN74AVCH8T245 support on its A and B ports?

The SN74AVCH8T245 supports independent supply voltages from 1.2V to 3.6V on both VCCA (A port) and VCCB (B port), enabling translation between any combination of 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V logic domains. This flexibility is built into the core architecture of the SN74AVCH8T245 and verified across all operating conditions.

How does the SN74AVCH8T245 handle power sequencing when VCCA or VCCB is unpowered?

The SN74AVCH8T245 implements VCC isolation: if either VCCA or VCCB drops to GND, all corresponding port outputs automatically enter high-impedance state. This prevents backfeeding and ensures safe power-up/down sequencing - a guaranteed behavior of the SN74AVCH8T245, not dependent on external circuitry.

Does the SN74AVCH8T245 require external pullup or pulldown resistors on its data lines?

No. The SN74AVCH8T245 integrates active bus-hold circuitry on all A1–A8 and B1–B8 pins, which maintains undriven inputs at valid logic levels. This eliminates the need for external pull resistors - a confirmed feature of the SN74AVCH8T245, validated in TI's characterization data and application notes.

What is the maximum data rate supported by the SN74AVCH8T245, and under what conditions?

The SN74AVCH8T245 achieves up to 320Mbps when both VCCA and VCCB are ≥1.8V. At lower supply combinations (e.g., VCCA ≤1.8V or VCCB ≤1.8V), the maximum rate reduces to 170Mbps. These values are measured and specified in the official SN74AVCH8T245 datasheet under defined load and transition conditions.

How is the direction-control (DIR) and output-enable (OE) logic referenced in the SN74AVCH8T245?

Both DIR and OE inputs in the SN74AVCH8T245 are referenced strictly to VCCA - meaning their VIH/VIL thresholds scale with the A-port supply voltage. This design ensures consistent control behavior regardless of VCCB level and is a defining architectural trait of the SN74AVCH8T245, explicitly documented in its pin-function table and electrical specifications.