Texas Instruments SN74LVCH245AZXYR

Overview

SN74LVCH245AZXYR from Texas Instruments is an octal bus transceiver with tri-state outputs, designed for 1.65 V to 3.6 V supply operation and supporting mixed-mode 5-V input/3.3-V V_CC interfacing. It features direction control (DIR), active-low output enable (OE), bus-hold on all data inputs, I_off for live insertion, and a maximum propagation delay of 6.3 ns at 3.3 V. It serves as a level-translating bidirectional data bridge in compact BGA systems.

For engineers reviewing the SN74LVCH245AZXYR datasheet, SN74LVCH245AZXYR pinout, SN74LVCH245AZXYR application, or SN74LVCH245AZXYR equivalent, this page delivers verified electrical specs, ZXY-package terminal mapping, real-world use cases in space-constrained embedded interfaces, and two validated alternative transceivers with documented functional and thermal trade-offs.

Technical Context

The SN74LVCH245AZXYR implements asynchronous bidirectional data transfer between two 8-bit buses using a single DIR signal to determine transmission direction (A→B or B→A), while OE independently places all outputs in high-impedance state. Its I_off circuitry ensures back-drive protection during partial power-down, and integrated bus-hold latches eliminate external pull resistors on floating A/B port inputs.

It operates across –40°C to +125°C with guaranteed switching performance up to 3.3 V, supports 5.5-V-tolerant inputs regardless of V_CC, and exhibits low ground bounce (V_OLP < 0.8 V) and undershoot (V_OHV > 2 V) at 3.3 V - critical for signal integrity in high-speed digital interconnects.

Key Specifications

Pinout & Package

MICROSTAR JUNIOR BGA package (ZXY), 20-terminal, 0.4-mm pitch, 3.0 mm × 2.5 mm body size, bottom-side solder balls.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVCH245AZXYR, SN74LVC245AQPWRQ1 trades bus-hold and speed for automotive qualification, while SN74AVC245ZRGR offers faster timing and lower V_CC at the cost of larger footprint and no I_off protection - making SN74LVCH245AZXYR optimal for space-constrained industrial and computing applications needing integrated bus-hold and live-insertion safety.

Availability

SN74LVCH245AZXYR is available at Aetrix Electronics and suitable for server memory interconnects, industrial PLC backplanes, wearable health sensor hubs, and automotive infotainment gateways requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVCH245AZXYR 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 specializing in analog, embedded processing, and connectivity solutions, with over 90 years of innovation in industrial, automotive, and communications markets.

The SN74LVCH245A product line delivers robust, low-voltage octal transceivers optimized for mixed-signal interfacing in space-constrained, thermally demanding embedded systems - emphasizing I_off, bus-hold, and 5-V-tolerant I/O for seamless legacy integration.

FAQ

What is the minimum V_CC required for reliable operation of the SN74LVCH245AZXYR?

The SN74LVCH245AZXYR is fully specified down to 1.65 V V_CC across its entire operating temperature range (–40°C to +125°C). Below 1.65 V, functionality is not guaranteed - for example, bus-hold current drops below specification at 1.5 V, and propagation delay exceeds 6.3 ns. The device supports data retention only at 1.5 V, not active operation.

Does the SN74LVCH245AZXYR require external pull-up or pull-down resistors on its A/B port pins?

No. The SN74LVCH245AZXYR integrates active bus-hold circuitry on all 16 A/B port inputs, which maintains valid logic states on floating lines without external resistors. Using external pull components alongside bus-hold is explicitly discouraged in the datasheet, as it may cause contention and increased power consumption.

Can the SN74LVCH245AZXYR safely interface a 5-V microcontroller GPIO with a 1.8-V FPGA I/O bank?

Yes - the SN74LVCH245AZXYR accepts 5.5-V-tolerant inputs regardless of V_CC, so a 5-V MCU output can drive any A/B input directly. However, its outputs swing only from GND to V_CC; to drive a 1.8-V FPGA, V_CC must be set to 1.8 V, and the FPGA must tolerate 1.8-V logic levels. The device does not perform active level shifting on outputs.

What is the thermal performance of the SN74LVCH245AZXYR in its native MICROSTAR JUNIOR BGA package?

The SN74LVCH245AZXYR in the ZXY package has a junction-to-ambient thermal resistance (R_θJA) of 123.5 °C/W under standard JEDEC test conditions. This value assumes minimal copper pour; actual board-level thermal performance improves significantly with ≥2 oz. internal ground/power planes and thermal vias beneath the package.

How does the I_off feature of the SN74LVCH245AZXYR protect the system during partial power-down?

The I_off circuitry in the SN74LVCH245AZXYR disables all I/O buffers when V_CC = 0 V, limiting leakage current to ±20 µA per pin. This prevents damaging back-current flow from powered downstream buses into the unpowered transceiver - a critical safeguard during hot-swap events or staggered power sequencing in modular systems.