Texas Instruments SN74F245NE4

Overview

SN74F245NE4 from Texas Instruments is an octal bus transceiver with 3-state outputs, designed for asynchronous bidirectional data transfer between two 8-bit buses. It features direction control (DIR) and output enable (OE) inputs, operates at 5 V, supports 0°C to 70°C temperature range, and uses a 20-pin plastic DIP (N) package for through-hole mounting in legacy industrial control and instrumentation systems.

For engineers reviewing the SN74F245NE4 datasheet, SN74F245NE4 pinout, SN74F245NE4 application, or SN74F245NE4 equivalent, this page delivers verified electrical specs, functional truth table behavior, thermal and switching performance under 5 V/50 pF conditions, and precise mechanical package dimensions - all critical for bus isolation, level translation, and PCB layout validation in retrofitted or long-lifecycle designs.

Technical Context

The SN74F245NE4 implements TTL-compatible bipolar F-family logic with open-collector–like 3-state output drivers capable of driving standard bus loads directly. Its DIR input selects data flow direction (A→B or B→A), while OE independently disables all outputs into high-impedance state for bus isolation - enabling shared-bus arbitration without external gating.

It exhibits typical propagation delays of 1.7–7 ns (tPLH/tPHL) and 1.2–9 ns (output enable/disable transitions) at VCC = 5 V and CL = 50 pF, with guaranteed IOL up to 64 mA on B-side outputs and 24 mA on A-side outputs - supporting robust drive strength for legacy backplane and parallel interface applications.

Key Specifications

Pinout & Package

SN74F245NE4 uses a 20-pin plastic dual in-line package (PDIP-N) with 0.3-inch body width and 0.1-inch pin pitch, optimized for manual soldering and socket-based testing in development and maintenance environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS245N and 74F245SC, the SN74F245NE4 uniquely combines F-series speed and drive strength with through-hole PDIP packaging - making it the only drop-in solution for upgrading legacy LS-based systems without PCB redesign or socket replacement.

Availability

SN74F245NE4 is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy microcontroller expansion buses, automated test equipment signal routing, and avionics diagnostic adapters requiring stable component supply across extended product lifecycles.

Supply support for SN74F245NE4 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 U.S.-based semiconductor company founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The SN74F245NE4 belongs to TI's 74F logic family - engineered for high-speed, low-power TTL-compatible operation in mission-critical control and instrumentation systems where reliability and long-term availability are essential.

FAQ

What is the maximum sink current supported by SN74F245NE4 on its B-side outputs?

The SN74F245NE4 supports up to 64 mA sink current on B1–B8 outputs under recommended operating conditions (VCC = 4.5 V, TA = 0°C to 70°C). This value is specified in the "electrical characteristics" table for IOL (B1 thru B8) at VCC = 4.5 V and IOL = 64 mA, ensuring robust drive capability for legacy TTL bus loads without external buffers. The SN74F245NE4 maintains this rating across its full commercial temperature range.

Does SN74F245NE4 support bidirectional data flow without external logic?

Yes, the SN74F245NE4 supports fully bidirectional data flow using only its DIR input - no external gates or controllers are needed. When DIR = Low, data transfers from B bus to A bus; when DIR = High, data flows from A bus to B bus. This native bidirectional capability is intrinsic to the SN74F245NE4 architecture and is validated in the device's FUNCTION TABLE, enabling simple, low-component-count bus interfacing.

Can SN74F245NE4 be used in place of SN74LS245N in an existing design?

SN74F245NE4 can replace SN74LS245N in most cases due to identical pinout, voltage levels, and function, but with key improvements: faster propagation (7 ns vs. 25 ns), higher output drive (64 mA vs. 24 mA), and lower input current (0.1 mA vs. 0.4 mA). The SN74F245NE4 is a direct functional upgrade - however, verify timing margins and bus loading, as the increased speed may expose marginal trace lengths or terminations previously masked by LS-family slowness.

What is the meaning of the "E4" suffix in SN74F245NE4?

The "E4" suffix in SN74F245NE4 denotes Texas Instruments' standard RoHS-compliant, lead-free, NiPdAu-plated PDIP package variant. It indicates compliance with JEDEC J-STD-609A Class 2a marking and IPC-1752 material declaration requirements. The SN74F245NE4 shares identical electrical and thermal specifications with SN74F245N but adds environmental compliance for new production - making it the preferred choice for updated manufacturing releases.

Is SN74F245NE4 compatible with 3.3 V logic systems?

No, the SN74F245NE4 is not compatible with 3.3 V logic systems. It is a 5 V-only TTL device with VIH = 2 V minimum and VIL = 0.8 V maximum - designed for 5 V supply and signaling. Driving its inputs from 3.3 V sources may result in unreliable high-level recognition, and connecting its 5 V outputs to 3.3 V–tolerant inputs risks overvoltage damage. For mixed-voltage systems, level-shifting circuitry or a 3.3 V–compatible transceiver such as SN74LVC245A must be used instead of the SN74F245NE4.