NXP Semiconductors N74F786N,602

Overview

N74F786N,602 from Philips Semiconductors is a 4-bit asynchronous bus arbiter IC in 16-pin plastic DIP (SOT38-4) packaging, operating at 5V ±10%, with 6.6ns typical propagation delay (BRn to BGn), metastable-free outputs, and industrial temperature range support (–40°C to +85°C). It resolves contention among four active-low bus request inputs using first-come-first-served priority and drives four active-low grant outputs under common enable control.

For engineers reviewing the N74F786N,602 datasheet, N74F786N,602 pinout, N74F786N,602 application, or N74F786N,602 equivalent, key selection considerations include its asynchronous arbitration logic, guaranteed metastability immunity, EN-controlled output enable, integrated 4-input AND gate, and compatibility with TTL/FAST logic families in real-time multi-master bus systems.

Technical Context

The N74F786N,602 implements fully asynchronous arbitration without internal clocks-priority is assigned dynamically as BR0–BR3 inputs assert low, with no fixed hierarchy. Its internal latching structure ensures metastable-free BGn outputs even during simultaneous request assertion, though tPHL may increase under such conditions.

It integrates a standalone 4-input AND gate (pins A–D → YOUT) usable independently of arbitration logic. All outputs (BG0–BG3, YOUT) drive 24mA low / 3mA high per FAST unit load, and EN input enables/disables all BGn outputs simultaneously while maintaining arbitration state.

Key Specifications

Pinout & Package

Package: 16-pin plastic dual in-line package (DIP), SOT38-4, 300 mil width, through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74F786N and 74ACT786PC, the N74F786N,602 offers guaranteed industrial temperature operation and proven metastability immunity at the cost of higher supply current-making it the sole choice for legacy-replacement and harsh-environment arbitration where reliability trumps power efficiency.

Availability

N74F786N,602 is available at Aetrix Electronics and suitable for multi-master microprocessor buses, industrial PLC backplanes, legacy TTL system expansions, and distributed test equipment interfaces requiring stable component supply over extended production lifecycles.

Supply support for N74F786N,602 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

Philips Semiconductors (now NXP Semiconductors) was a pioneering European semiconductor manufacturer known for industry-standard logic families and automotive ICs.

The 74F786 belongs to Philips' FAST TTL logic family, designed specifically for high-speed, metastability-immune bus arbitration in real-time embedded systems where deterministic response and multi-clock-domain interoperability are critical.

FAQ

What is the maximum operating temperature range supported by the N74F786N,602?

The N74F786N,602 supports an industrial temperature range of –40°C to +85°C, as confirmed in the Philips Semiconductor Product Specification dated February 14, 1991. This rating applies to the N74F786N variant (plastic DIP), which matches the N74F786N,602 ordering code. Operation outside this range may impair functionality or reliability.

Does the N74F786N,602 require external clocking or synchronization circuitry?

No, the N74F786N,602 operates asynchronously and requires no external clock. Its arbitration logic responds directly to edge transitions on BR0–BR3 inputs, and its metastable-free design eliminates the need for external synchronizers-even when request signals originate from unrelated clock domains. This behavior is explicitly guaranteed in the Functional Description section of the datasheet.

Can unused bus request inputs (BR0–BR3) be left floating on the N74F786N,602?

No-unused BRn inputs on the N74F786N,602 must be tied high (to VCC via pull-up or direct connection) as stated in the PIN DESCRIPTION table. Floating inputs risk indeterminate logic states, unintended arbitration triggers, and increased susceptibility to noise-induced glitches, compromising the guaranteed metastability immunity.

What is the purpose of the YOUT pin on the N74F786N,602?

The YOUT pin on the N74F786N,602 is the output of the integrated 4-input AND gate formed by inputs A, B, C, and D. It functions independently of the arbitration logic, providing combinational logic capability with identical electrical characteristics (24mA sink, 3mA source, 6.6ns typical delay) as the BGn outputs-enabling consolidation of glue logic and arbitration in one IC.

How does the EN pin affect arbitration state retention in the N74F786N,602?

When EN is high, all BG0–BG3 outputs are forced high, but the internal arbitration queue retains its state-including pending requests and priority order. Upon EN returning low, arbitration resumes immediately from the preserved state without reinitialization or loss of queued requests, as documented in the Functional Description section of the N74F786N,602 datasheet.