Texas Instruments SN74AXCH4T245PWR

Overview

SN74AXCH4T245 from Texas Instruments is a four-bit noninverting bus transceiver with dual-rail voltage translation (0.65 V to 3.6 V per port), tri-state outputs, and bus-hold inputs on all data I/Os. It supports bidirectional asynchronous data transfer between A and B buses, enables simultaneous up/down translation via independent DIR pins, and operates across –40°C to +125°C for industrial and automotive interface applications.

For engineers reviewing the SN74AXCH4T245 datasheet, SN74AXCH4T245 pinout, SN74AXCH4T245 application, or SN74AXCH4T245 equivalent, key selection considerations include configurable dual-supply operation, VCC isolation, Ioff partial-power-down support, glitch-free power sequencing, and bus-hold elimination of external resistors.

Technical Context

The SN74AXCH4T245 implements two independent transceiver pairs (1A↔1B and 2A↔2B), each controlled by dedicated direction (xDIR) and output-enable (xOE) inputs referenced solely to VCCA. Its fully configurable dual-rail architecture allows VCCA and VCCB to operate independently within 0.65 V–3.6 V, enabling level shifting across disparate logic families without external components.

Bus-hold circuitry is embedded only on data I/O pins (1A1, 1A2, 2A1, 2A2, 1B1, 1B2, 2B1, 2B2), actively maintaining valid logic states on undriven inputs; control inputs (xDIR, xOE) lack bus-hold and must be actively driven. The VCC isolation feature forces all I/Os into high-impedance when either VCCA or VCCB falls below 100 mV.

Key Specifications

Pinout & Package

TSSOP-16 package (5.00 mm × 4.40 mm), lead pitch 0.65 mm, thermally enhanced with two GND pins (pins 8 and 9) for noise suppression and thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AXCH4T245PWR, SN74AVCH4T245PWR trades VCC isolation and higher drive for faster edge rates, while SN74LXC4T245PWR extends voltage range and cuts quiescent current but omits isolation-making SN74AXCH4T245PWR the optimal choice for safety-critical power-sequencing environments.

Availability

SN74AXCH4T245PWR is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive ADAS sensor hubs, and enterprise SSD controller bridges requiring stable component supply, extended temperature operation, and robust power sequencing behavior.

Supply support for SN74AXCH4T245PWR 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 communications markets.

The AXCH family targets high-reliability, multi-voltage interface applications where robust power sequencing, bus stability, and wide operating temperature are mandatory - designed specifically for mission-critical industrial and automotive subsystems.

FAQ

What is the minimum operating voltage for SN74AXCH4T245PWR on each supply rail?

The SN74AXCH4T245PWR supports VCCA and VCCB as low as 0.65 V each, enabling direct interfacing with emerging sub-1V logic families such as advanced AI accelerators and ultra-low-power microcontrollers. This specification is validated across the full –40°C to +125°C temperature range and is not dependent on load conditions or data rate.

Does SN74AXCH4T245PWR require external pullup or pulldown resistors on its data lines?

No. The SN74AXCH4T245PWR integrates bus-hold circuitry on all eight data I/O pins (1A1, 1A2, 2A1, 2A2, 1B1, 1B2, 2B1, 2B2), which actively maintains valid logic states on undriven or floating inputs. External resistors are explicitly discouraged in the datasheet and would degrade noise margin and increase power consumption.

How does the VCC isolation feature function in SN74AXCH4T245PWR?

The VCC isolation feature in SN74AXCH4T245PWR monitors both VCCA and VCCB; if either supply falls below 100 mV, all I/O ports immediately enter a high-impedance state regardless of xDIR/xOE logic levels. This prevents signal contention and back-driving during brownout, hot-swap, or staged power-down sequences in modular systems.

Can SN74AXCH4T245PWR support simultaneous bidirectional translation on its two transceiver pairs?

Yes. SN74AXCH4T245PWR provides two independent transceiver pairs (1A↔1B and 2A↔2B), each with dedicated direction-control (1DIR/2DIR) and output-enable (1OE/2OE) inputs. This allows one pair to translate A→B while the other translates B→A concurrently - essential for full-duplex protocols like SPI or proprietary sensor command/response interfaces.

What is the maximum data rate supported by SN74AXCH4T245PWR in a 1.8V-to-3.3V translation configuration?

The SN74AXCH4T245PWR supports up to 380 Mbps in 1.8V-to-3.3V translation, verified under recommended operating conditions (TA = –40°C to +85°C). This performance is achieved with propagation delay as low as 6 ns (A→B) and 4 ns (B→A) at VCCA = 1.8 V and VCCB = 3.3 V, meeting timing budgets for high-throughput industrial Ethernet and PCIe Gen1 bridging applications.