Texas Instruments SN74LVTH2245DBR

Overview

SN74LVTH2245DBR from Texas Instruments is an octal bus transceiver designed for 3.3-V V_CC operation with mixed-mode 5-V input/output tolerance, supporting bidirectional data flow between A and B buses via DIR control and isolation via OE. It features bus-hold on all data inputs, 22-Ω integrated series resistors on B-port outputs, and I_off/power-up 3-state for hot insertion in industrial backplane and legacy interface bridging applications.

For engineers reviewing the SN74LVTH2245DBR datasheet, SN74LVTH2245DBR pinout, SN74LVTH2245DBR application, or SN74LVTH2245DBR equivalent, key selection criteria include its 2.7–3.6-V supply range, ±12 mA B-port drive, 4.2 ns typical propagation delay (B→A), 20-pin SSOP package with 0.65-mm pitch, and support for unregulated battery operation down to 2.7 V.

Technical Context

This device implements TTL-compatible level translation between 3.3-V logic domains and 5-V systems using dual-bus architecture with direction-controlled bidirectional data paths. Its DIR input selects A→B or B→A transmission, while OE enables high-impedance isolation of both buses simultaneously.

The integrated bus-hold circuitry maintains valid logic states on floating A/B inputs without external resistors, and the B-port's 22-Ω series termination reduces overshoot/undershoot during 12-mA switching. I_off protection limits current backflow when powered down, and power-up 3-state ensures safe hot-plug operation.

Key Specifications

Pinout & Package

SN74LVTH2245DBR uses a 20-pin SSOP (DB) package with 0.65-mm lead pitch, 7.4-mm body width, and 2-mm max height per JEDEC MO-150. Pin 1 index area located at top-left corner (quadrant Q1 in tape).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC2245APW and SN74ALVC162245DL, SN74LVTH2245DBR uniquely combines bus-hold, I_off, and 5-V tolerance in an 8-bit SSOP package-making it optimal for industrial hot-swap and legacy interface bridging where reliability and component count reduction are critical.

Availability

SN74LVTH2245DBR is available at Aetrix Electronics and suitable for industrial backplane interface, legacy system bridging, hot-swappable module interface, and low-power battery-powered data link applications requiring stable component supply across extended temperature ranges (−40°C to 85°C).

Supply support for SN74LVTH2245DBR 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 90 years of innovation in industrial, automotive, and communications markets.

The SN74LVTH2245DBR belongs to TI's LVTH logic family, engineered specifically for robust 3.3-V/5-V mixed-signal interfacing in harsh industrial environments where voltage translation, hot-swap resilience, and bus stability are mission-critical.

FAQ

What is the maximum recommended supply voltage for SN74LVTH2245DBR?

The absolute maximum V_CC rating for SN74LVTH2245DBR is 4.6 V, but the recommended operating range is strictly 2.7 V to 3.6 V per the datasheet. Operating above 3.6 V risks parametric degradation and reduced long-term reliability, even if functional at 4.6 V momentarily. SN74LVTH2245DBR must be powered within this 2.7–3.6-V window for guaranteed timing, drive strength, and bus-hold behavior.

Does SN74LVTH2245DBR require external pullup resistors on its data inputs?

No. SN74LVTH2245DBR integrates active bus-hold circuitry on all A and B data inputs, which maintains valid logic states on floating or unused pins without external components. Using pullup or pulldown resistors with SN74LVTH2245DBR is explicitly discouraged in the datasheet, as it may interfere with bus-hold current thresholds and cause unpredictable logic levels.

Can SN74LVTH2245DBR safely interface a 3.3-V microcontroller with a 5-V UART transceiver?

Yes. SN74LVTH2245DBR supports 5-V input and output voltage tolerance while operating from a 3.3-V V_CC, making it ideal for connecting 3.3-V logic to 5-V peripherals like MAX232-level UART transceivers. Its B-port outputs deliver ±12 mA into 5-V loads, and inputs accept 0–5.5-V signals - all without level-shifting components. SN74LVTH2245DBR ensures signal integrity and timing compliance in this configuration.

What is the thermal resistance (θ_JA) of the SN74LVTH2245DBR in its SSOP package?

The junction-to-ambient thermal resistance (θ_JA) for SN74LVTH2245DBR in the SSOP (DB) package is 70 °C/W, measured under standard JEDEC conditions. This value assumes a two-layer PCB with 1-in² copper pour under the package. For sustained 64-mA A-port switching or ambient temperatures approaching 85°C, derating or additional copper thermal vias are recommended to maintain junction temperature below 125°C. SN74LVTH2245DBR's thermal performance is validated per JEDEC JESD 51-7.

How does the I_off feature protect SN74LVTH2245DBR during hot insertion?

The I_off circuitry in SN74LVTH2245DBR disables all outputs when V_CC = 0 V, limiting current flow to ±100 µA even if 5-V signals are present on A/B ports. This prevents damaging back-current from live backplanes into the unpowered IC during hot insertion. Combined with power-up 3-state, SN74LVTH2245DBR achieves full hot-swap compliance - a key differentiator versus standard LVC or ALVC transceivers lacking I_off.