Texas Instruments SN74ABT2245DBRG4

Overview

SN74ABT2245DBRG4 from Texas Instruments is an octal transceiver and line driver with 3-state outputs, designed for asynchronous bidirectional data bus communication between A- and B-buses. It features direction control (DIR), output enable (OE), 25-Ω integrated series resistors on B-port outputs, ±12 mA B-port drive, and 64 mA A-port sink capability at VCC = 4.5–5.5 V. It operates from –40°C to 85°C in a 20-pin SSOP (DB) package.

For engineers reviewing the SN74ABT2245DBRG4 datasheet, SN74ABT2245DBRG4 pinout, SN74ABT2245DBRG4 application, or SN74ABT2245DBRG4 equivalent, key selection criteria include bidirectional bus isolation timing (tPLH/tPHL ≤ 4.5 ns), high-impedance state during power-up/down, latch-up immunity (>500 mA), and compatibility with 5-V TTL/CMOS logic systems.

Technical Context

This device implements dual 8-bit bidirectional data paths controlled by DIR and OE inputs, enabling A→B or B→A transmission or full bus isolation. Its EPIC-II^B BiCMOS process delivers low power dissipation while maintaining TTL-compatible voltage thresholds (VIH = 2 V, VIL = 0.8 V) and robust noise margins (Vhys = 100 mV).

The B-port outputs integrate 25-Ω series resistors to suppress overshoot/undershoot without external components; A-port outputs support higher current (64 mA sink) but lack internal termination. High-impedance state is guaranteed during VCC ramp (0–2.1 V), and OE must be pulled up above 2.1 V for reliable disable behavior.

Key Specifications

Pinout & Package

SN74ABT2245DBRG4 is housed in a 20-pin Shrink Small-Outline Package (SSOP, DB), 7.5 mm × 5.6 mm footprint, 1.2 mm max height, RoHS-compliant NIPDAU lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC2245APW, SN74ABT2245DBRG4 delivers higher drive strength and built-in termination for 5-V systems, while SN74ABT245DBR offers identical functionality without the G4 suffix-making it suitable for cost-sensitive or non-G4-audited designs.

Availability

SN74ABT2245DBRG4 is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy bus extensions, automated test equipment signal routing, and programmable logic glue logic requiring stable component supply and long-term obsolescence management.

Supply support for SN74ABT2245DBRG4 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 logic solutions, with decades of heritage in industry-standard logic families.

The ABT logic family-including SN74ABT2245DBRG4-is engineered for high-speed, 5-V TTL-compatible bus interfacing in industrial, test, and legacy computing applications where robustness and timing predictability are critical.

FAQ

What is the maximum clock/data rate supported by SN74ABT2245DBRG4?

SN74ABT2245DBRG4 does not operate on a clock; it is an asynchronous transceiver. Its 4.5 ns max propagation delay (tPLH/tPHL) supports reliable data transfer up to ~100 MHz in well-terminated 50-pF load conditions, assuming setup/hold timing is met by the controlling logic.

Does SN74ABT2245DBRG4 require external pull-up resistors on DIR or OE?

OE must be tied to VCC through a pull-up resistor (value determined by driver strength) to ensure high-impedance state above 2.1 V; DIR may float only if actively driven, as floating inputs risk undefined direction control and increased ICC. TI recommends tying unused control inputs to VCC or GND.

Can SN74ABT2245DBRG4 interface directly with 3.3-V logic?

No-SN74ABT2245DBRG4 is a 5-V-only device (VCC = 4.5–5.5 V). Its VIH = 2 V and VIL = 0.8 V allow it to accept 3.3-V logic levels as inputs, but its outputs swing rail-to-rail at 5 V and will overdrive 3.3-V inputs unless level-shifted or clamped.

What is the thermal resistance (θJA) of SN74ABT2245DBRG4 in its DB package?

The SN74ABT2245DBRG4 in the SSOP (DB) package has a specified junction-to-ambient thermal resistance (θJA) of 115°C/W under JEDEC-standard PCB mounting conditions, which informs derating curves for continuous operation above 70°C ambient.

Is SN74ABT2245DBRG4 pin-compatible with other packages in the same family?

Yes-SN74ABT2245DBRG4 shares identical 20-pin functional pinout with SN74ABT2245DW (SOIC), SN74ABT2245N (PDIP), and SN74ABT2245PW (TSSOP); however, mechanical dimensions, thermal performance, and soldering profiles differ significantly between packages.