Texas Instruments SN74ABTR2245DBR

Overview

SN74ABTR2245DBR from Texas Instruments is an octal transceiver with 3-state outputs, designed for asynchronous bidirectional data bus communication between A and B ports. It features integrated 25-Ω series output resistors, operates at 4.5–5.5 V, supports –40°C to 85°C, and delivers tPLH/tPHL ≤ 4 ns (VCC = 5 V, CL = 50 pF). It is used in memory interface and bus isolation applications requiring low ground bounce (VOLP < 1 V) and high-impedance safety during power sequencing.

For engineers reviewing the SN74ABTR2245DBR datasheet, SN74ABTR2245DBR pinout, SN74ABTR2245DBR application, or SN74ABTR2245DBR equivalent, key selection criteria include direction-control logic behavior, 12-mA drive capability per port, 25-Ω on-die termination, thermal performance (θJA = 115°C/W), and compatibility with SOIC-20 (DB) footprint constraints.

Technical Context

This BiCMOS transceiver implements dual 8-bit bidirectional data paths controlled by DIR (direction) and OE (output enable) inputs. Its EPIC-II^B architecture enables low-power operation while maintaining TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V) and rail-to-rail output swing under 12-mA load.

Power-up/power-down behavior is defined by internal high-impedance state activation below 2.1 V on VCC; above that threshold, OE must be actively pulled high via external resistor to guarantee isolation. Output clamping and latch-up immunity (>500 mA per JESD-17) support robust operation in noisy industrial environments.

Key Specifications

Pinout & Package

The SN74ABTR2245DBR is housed in a 20-pin Shrink Small-Outline (DB) package, 7.5 mm × 4.4 mm, 1.2 mm max height, with 0.65 mm lead pitch and gull-wing leads. Pin 1 is located at top-left corner with index marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC2245APWR and SN74ABT245N, the SN74ABTR2245DBR uniquely combines 5-V operation, on-die 25-Ω termination, and SOIC-20 surface-mount packaging-making it optimal for space-constrained industrial bus isolation where external resistors and voltage translation are undesirable.

Availability

SN74ABTR2245DBR is available at Aetrix Electronics and suitable for memory bus isolation, industrial backplane interfacing, and legacy system bus extension requiring stable component supply and long-term industrial temperature support.

Supply support for SN74ABTR2245DBR 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 experience in high-reliability interface ICs.

The ABTR-series transceivers were developed for robust 5-V bus interfacing in industrial and computing systems, emphasizing noise immunity, power sequencing safety, and reduced external component count.

FAQ

What is the recommended power-up sequence for SN74ABTR2245DBR?

The SN74ABTR2245DBR automatically enters high-impedance state when VCC is below 2.1 V. To ensure isolation above that threshold, OE must be tied to VCC via a pullup resistor (minimum value determined by driver sink capability). No specific sequencing of DIR or OE relative to VCC is required beyond this biasing, making SN74ABTR2245DBR tolerant of uncontrolled power ramp rates up to 200 µs/V.

Does SN74ABTR2245DBR require external series resistors on its I/O lines?

No. The SN74ABTR2245DBR integrates 25-Ω series resistors on all A- and B-port outputs, explicitly eliminating the need for external termination components. This feature is confirmed in the device description and output schematic of the official datasheet, and applies directly to the SN74ABTR2245DBR variant in DB package.

Can SN74ABTR2245DBR operate at 3.3 V?

No. The SN74ABTR2245DBR is specified only for 4.5 V to 5.5 V supply operation per its recommended operating conditions. Attempting 3.3-V operation violates the minimum VCC requirement and will result in undefined logic levels, excessive ICC, or failure to meet timing specifications. For 3.3-V systems, consider SN74LVC2245 instead.

What is the maximum capacitive load SN74ABTR2245DBR can drive reliably?

The SN74ABTR2245DBR switching characteristics are characterized with CL = 50 pF, and propagation delays remain within spec up to this load. While the device can physically drive higher capacitance, timing margins degrade beyond 50 pF; for loads exceeding 50 pF, derating analysis using tPLH/tPHL vs. CL curves (if available) or empirical validation is required. The SN74ABTR2245DBR is not rated for transmission-line driving.

How does the DIR input affect data flow direction in SN74ABTR2245DBR?

In SN74ABTR2245DBR, DIR = Low enables data transmission from B bus to A bus; DIR = High enables transmission from A bus to B bus. This behavior is defined in the FUNCTION TABLE and verified across all operating conditions. When OE is High, both directions are disabled regardless of DIR state-ensuring complete bus isolation.