Texas Instruments SN74F245NG4

Overview

SN74F245NG4 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 4.5–5.5 V, supports 0°C to 70°C ambient, and delivers 128 mA sink current on B-side outputs - enabling direct drive of TTL/CMOS bus loads in industrial backplane and legacy system interconnect applications.

For engineers reviewing the SN74F245NG4 datasheet, SN74F245NG4 pinout, SN74F245NG4 application, or SN74F245NG4 equivalent, this page provides verified functional identity, validated pin mapping for PDIP-20, confirmed switching timing (tPLH/tPHL ≤ 7 ns), absolute maximum ratings, and two rigorously cross-referenced alternative parts for legacy system redesign and supply continuity planning.

Technical Context

The SN74F245NG4 implements a dual-bus bidirectional transceiver architecture with independent DIR and OE logic control. Its 3-state outputs isolate buses when OE is high, while DIR selects A→B (high) or B→A (low) data flow - supporting full-duplex arbitration-free communication in shared-bus systems.

It uses F-series TTL-compatible input thresholds (VIH = 2 V, VIL = 0.8 V), delivers VOH ≥ 2.4 V at IOH = –3 mA (A-side) and ≥ 2.0 V at –15 mA (B-side), and exhibits VOL ≤ 0.55 V at IOL = 64 mA (B-side), ensuring robust noise margin and load driving capability across temperature.

Key Specifications

Pinout & Package

SN74F245NG4 is supplied in a 20-pin plastic dual in-line package (PDIP), with 0.3-inch body width and standard DIP footprint. Pin 1 is located at the top-left corner adjacent to the notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74F245NG4, SN74LS245N trades speed and drive for cost and legacy compatibility, while SN74HC245N offers voltage flexibility and low quiescent current at the expense of TTL-level drive strength - making SN74F245NG4 the optimal choice for unmodified 5 V TTL bus loading and sub-10 ns timing budgets.

Availability

SN74F245NG4 is available at Aetrix Electronics and suitable for industrial backplane interconnect, legacy computer system expansion, and automated manufacturing fixture interface requiring stable component supply and long-term obsolescence management.

Supply support for SN74F245NG4 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 founded in 1930, specializing in analog, embedded processing, and logic solutions with deep heritage in TTL and advanced logic families.

The SN74F245NG4 belongs to TI's F-series fast TTL logic product line, engineered specifically for high-speed, high-drive 5 V bus interfacing in industrial control, test equipment, and retro-computing applications where timing predictability and load tolerance are critical.

FAQ

What is the maximum operating temperature range for SN74F245NG4?

The SN74F245NG4 is rated for operation from 0°C to 70°C - consistent with commercial-grade temperature specifications. This range supports deployment in non-temperature-controlled industrial cabinets and desktop computing environments. It is distinct from the military-grade SN54F245, which operates from –55°C to 125°C. The SN74F245NG4 datasheet confirms this limit under Recommended Operating Conditions and Absolute Maximum Ratings tables.

Does SN74F245NG4 support true bidirectional data transfer without external logic?

Yes, SN74F245NG4 supports true bidirectional data transfer using only its DIR and OE inputs - no external gates or controllers required. When OE is low, asserting DIR high enables A-to-B transmission, while DIR low enables B-to-A transmission. This single-chip solution replaces discrete AND/OR logic and directional buffers, reducing PCB area and signal path delay in bus arbitration schemes.

What is the output drive capability of SN74F245NG4 on the B-side pins?

The SN74F245NG4 B-side outputs (B1–B8) deliver up to 128 mA sink current per pin at VCC = 5.5 V and TA = 25°C, as specified in the Absolute Maximum Ratings table. This allows direct driving of up to 10 standard TTL loads or heavy capacitive bus lines. Actual usable current depends on junction temperature and voltage drop; design margin should maintain VOL ≤ 0.55 V at 64 mA per pin under worst-case conditions.

Can SN74F245NG4 be used in place of SN74LS245N in an existing design?

SN74F245NG4 can replace SN74LS245N in most cases due to identical pinout and function, but requires verification of timing and power constraints. SN74F245NG4 offers faster propagation (≤7 ns vs. ≤15 ns) and higher drive (128 mA vs. 24 mA), which may improve margin but could increase ground bounce. Ensure VCC decoupling and layout accommodate higher di/dt; confirm OE/DIR timing relationships remain valid with reduced delays.

Is SN74F245NG4 RoHS compliant?

Yes, SN74F245NG4 is RoHS compliant, as confirmed by Texas Instruments' packaging documentation. The "G4" suffix denotes lead-free (NIPDAU) finish and RoHS-compliant materials per TI's official package addendum. It meets EU Directive 2011/65/EU requirements and carries appropriate markings on the package body (e.g., "G4" or "RoHS" laser etch). Full compliance documentation is available in TI's Quality & Environmental section.