Texas Instruments SN74LVCH245ADBR

Overview

SN74LVCH245ADBR from Texas Instruments is an octal bus transceiver with tri-state outputs, designed for bidirectional data translation between 1.65-V and 5-V logic domains in mixed-voltage systems. It operates from 1.65 V to 3.6 V, accepts 5.5-V-tolerant inputs, delivers 6.3 ns max propagation delay at 3.3 V, supports Ioff for live insertion, and integrates bus-hold on all A/B port inputs - enabling use in server backplanes and notebook I/O expansion.

For engineers reviewing the SN74LVCH245ADBR datasheet, SN74LVCH245ADBR pinout, SN74LVCH245ADBR application, or SN74LVCH245ADBR equivalent, key selection criteria include its 20-pin SSOP package, 1.65–3.6-V supply range, 5.5-V input tolerance, tri-state control via active-low OE, and direction control via DIR - all critical for voltage-level bridging in industrial and computing interfaces.

Technical Context

This device implements a dual-bus, bidirectional transceiver architecture with independent direction (DIR) and output-enable (OE) controls. Its CMOS inputs accept 5.5-V signals while operating from as low as 1.65 V, enabling seamless interfacing between legacy 5-V peripherals and modern 3.3-V or 1.8-V controllers. The integrated bus-hold circuitry actively maintains valid logic states on floating A/B inputs without external resistors.

The Ioff feature ensures isolation during partial power-down by disabling outputs when VCC = 0 V, preventing back-drive current flow. Output drive strength is balanced (±24 mA at 3 V), and switching performance is characterized across –40°C to 125°C with CL = 50 pF loads, supporting robust timing in thermally demanding embedded applications.

Key Specifications

Pinout & Package

SN74LVCH245ADBR is housed in a 20-pin SSOP (Shrink Small Outline Package) with 0.65-mm lead pitch and nominal body size 7.20 mm × 5.30 mm. This surface-mount package supports automated assembly and provides thermal resistance RθJA = 94.5°C/W, suitable for moderate-power digital interface applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC245A and 74ALVC16245, SN74LVCH245ADBR uniquely combines bus-hold, Ioff, and 5.5-V input tolerance in a compact 20-pin SSOP - making it optimal for space-constrained, mixed-voltage designs requiring zero-resistor input biasing and hot-plug safety.

Availability

SN74LVCH245ADBR is available at Aetrix Electronics and suitable for server backplanes, notebook I/O expansion, industrial PLC modules, telecom line cards, and wearable health device interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74LVCH245ADBR 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 technologies, with over 50 years of innovation in high-reliability interface solutions.

The SN74LVCH245A product line targets voltage-translation and bus-isolation needs in computing, communications, and industrial systems - delivering robust, low-power, mixed-signal interoperability without external passive components.

FAQ

What is the maximum input voltage rating for SN74LVCH245ADBR?

The SN74LVCH245ADBR supports input voltages up to 5.5 V across all A/B port pins, regardless of VCC level - enabling direct interfacing with 5-V TTL, LVTTL, or CMOS outputs without external clamping or level-shifting circuitry. This specification is guaranteed per TI's SCES008Q datasheet Section 6.1 Absolute Maximum Ratings.

Does SN74LVCH245ADBR require external pull-up or pull-down resistors on its data lines?

No - SN74LVCH245ADBR includes integrated bus-hold circuitry on all A1–A8 and B1–B8 inputs, which actively maintains valid logic states on floating lines. Using external resistors with this feature is not recommended, as it conflicts with internal biasing and may degrade noise immunity or increase power consumption.

Can SN74LVCH245ADBR be used in hot-swap applications?

Yes - SN74LVCH245ADBR incorporates Ioff circuitry that disables outputs when VCC = 0 V, preventing damaging back-current flow during live insertion or removal. This capability is validated per JESD78 and supports safe operation in modular telecom and server backplane systems where boards are replaced without powering down the chassis.

What is the propagation delay of SN74LVCH245ADBR at 1.8 V supply?

At VCC = 1.8 V ± 0.15 V and TA = –40°C to 85°C, the maximum propagation delay (tpd) of SN74LVCH245ADBR is 12.7 ns, as specified in Section 6.8 of the SCES008Q datasheet. This value applies to signal transmission from A to B or B to A ports under standard load conditions (CL = 50 pF).

How does the DIR pin control data flow direction in SN74LVCH245ADBR?

In SN74LVCH245ADBR, the DIR pin determines bidirectional data path: when DIR = HIGH, data flows from Port A to Port B; when DIR = LOW, data flows from Port B to Port A. This logic-level control operates independently of OE and remains functional across the full 1.65–3.6-V VCC range, enabling real-time bus arbitration in firmware-managed systems.