Texas Instruments SN74298N

Overview

SN74298N from Texas Instruments is a quad 2-input multiplexer with latched outputs, functioning as a data selector in TTL-level digital logic systems. It features 16-pin PDIP packaging, operates from 4.75V to 5.25V, supports propagation delay of 25 ns (typ), and delivers fan-out of 10 TTL loads - used in address/data routing for microprocessor peripheral interfaces.

For engineers reviewing the SN74298N datasheet, SN74298N pinout, SN74298N application, or SN74298N equivalent, key selection criteria include its dual-latch control architecture, complementary enable logic (active-low G̅), and guaranteed DC switching thresholds at V_CC = 5V ±5% across 0°C to 70°C ambient.

Technical Context

The SN74298N integrates four independent 2:1 multiplexers, each with separate data inputs (A/B), common output (Y), and individual latch-enable (LE) and gate-enable (G̅) controls. Its internal structure uses bipolar TTL circuitry with Schottky-clamped transistors to suppress saturation delay.

Each channel implements edge-triggered latching on LE rising edge while G̅ remains low; output states are held during G̅ high. Input thresholds meet standard TTL levels: V_IL ≤ 0.8V, V_IH ≥ 2.0V, ensuring interoperability with 74LS/74S families without level translation.

Key Specifications

Pinout & Package

SN74298N is housed in a 16-pin plastic dual in-line package (PDIP-N), with 0.300-inch wide body, through-hole mounting, and standard DIP pin spacing (0.100 inch).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multiplexer-with-latch applications.

Compared with SN74LS298N and 74F298PC, the SN74298N offers baseline TTL performance with proven reliability in long-lifecycle industrial control panels, trading speed and power for broad compatibility and thermal stability in uncooled enclosures.

Availability

SN74298N is available at Aetrix Electronics and suitable for microprocessor peripheral interfacing, industrial data acquisition systems, legacy bus arbitration, and automated test equipment requiring stable component supply over extended production lifecycles.

Supply support for SN74298N 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 SN74298N belongs to TI's legacy 74-series TTL logic product line, designed specifically for robust, drop-in replacement in maintenance and repair of aging digital control systems where modern logic families introduce compatibility risks.

FAQ

What is the function of the G̅ (gate-enable) pin on SN74298N?

The G̅ pin on SN74298N is an active-low global output enable that forces all four Y outputs to high-impedance when asserted (G̅ = HIGH), regardless of latch or select states. This allows bus isolation without altering internal latch contents. In normal operation (G̅ = LOW), outputs reflect the latched A/B/S states. The SN74298N uses open-collector compatible output structure, so external pull-ups are required for proper HIGH-level assertion.

Does SN74298N support 3.3V logic interfacing?

No, SN74298N does not support direct 3.3V logic interfacing. It is a standard TTL device requiring 4.75V–5.25V V_CC and exhibits TTL input thresholds (V_IH ≥ 2.0V, V_IL ≤ 0.8V). While 3.3V CMOS outputs may meet V_IH, they risk marginal noise immunity and cannot reliably drive SN74298N inputs across temperature and voltage extremes. Level translation is required for safe 3.3V-to-SN74298N interfacing.

How does the latch-enable (LE) behavior work on SN74298N?

Each channel of SN74298N features an independent LE input that captures the current A/B/S states on the rising edge of LE when G̅ is LOW. Once latched, the Y output holds that value until the next valid LE transition. LE is edge-sensitive, not level-sensitive - sustained LE HIGH does not cause repeated updates. This behavior makes SN74298N suitable for strobing asynchronous inputs like switch closures or sensor pulses without requiring synchronized clocks.

Is SN74298N RoHS compliant?

Yes, SN74298N is RoHS compliant, as confirmed by Texas Instruments' official packaging documentation. The device uses NiPdAu (NIPDAU) lead finish and meets EU Directive 2011/65/EU requirements for restricted substances. No exemptions apply. RoHS compliance is verified per TI's published material declarations and applies to all currently shipped SN74298N units from authorized distribution channels.

Can SN74298N replace SN74LS298N in existing PCBs?

SN74298N can physically replace SN74LS298N on the same PCB due to identical PDIP-16 packaging and pinout, but functional substitution requires design review. SN74298N has slower propagation delay (25 ns vs. 20 ns), higher power consumption (35 mW vs. 20 mW), and looser input thresholds. It may operate correctly in static or low-speed applications, but timing-critical systems should verify setup/hold margins and thermal rise before substitution. The SN74298N remains a valid choice for legacy repair where LS variants are unavailable.