Texas Instruments SN74H102N

Overview

SN74H102N from Texas Instruments (manufactured under license by Rochester Electronics) is a triple 3-input positive-NOR gate IC used for digital logic combining and signal inversion in TTL-compatible systems. It operates at VCC = 5 V, features typical propagation delay of 15 ns, fan-out of 10 TTL loads, and supports commercial temperature range (0°C to +70°C). It is commonly deployed in address decoding and control logic circuits within legacy industrial controllers.

For engineers reviewing the SN74H102N datasheet, SN74H102N pinout, SN74H102N application, or SN74H102N equivalent, key selection considerations include its 3-input NOR topology, TTL-level input thresholds, guaranteed DC output drive capability (IOH = –0.4 mA, IOL = 8 mA), and compatibility with standard 14-pin DIP packaging for through-hole prototyping and repair.

Technical Context

The SN74H102N implements three independent 3-input NOR gates in a single monolithic bipolar TTL device. Each gate provides active-low OR logic with wired-OR capability when outputs are open-collector-though SN74H102N uses standard totem-pole outputs, not open-collector. Its internal structure includes multi-emitter input transistors and phase-splitter-driven output stages optimized for speed-power trade-off in mid-1970s TTL families.

It belongs to the original 74H series, characterized by higher speed than standard 74-series but greater power consumption than 74L or 74LS. Input clamp diodes provide ESD protection, and output short-circuit duration is limited to avoid latch-up under transient overload conditions per TI's 1973 design specifications.

Key Specifications

Pinout & Package

SN74H102N is supplied in a 14-pin dual in-line package (DIP) with through-hole mounting. Pin spacing is 0.1 inch, body width is 0.3 inches, and lead finish is tin-lead (SnPb).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-input NOR gate applications.

Compared with SN74H102N, SN74LS10 offers lower power but looser timing guarantees, while SN74F10 delivers superior speed at the cost of higher supply current and stricter layout requirements-neither is pin-compatible without validation of load capacitance and trace impedance.

Availability

SN74H102N is available at Aetrix Electronics and suitable for industrial control panels, legacy test equipment, and military avionics spares requiring stable component supply and long-term obsolescence support.

Supply support for SN74H102N 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 pioneered the 7400-series TTL logic family in the 1960s; Rochester Electronics manufactures SN74H102N under authorized license using original TI die or recreated wafers qualified to MIL-PRF-35835.

The SN74H102N belongs to the 74H (High-Speed TTL) product line, designed specifically for applications demanding faster switching than standard TTL while maintaining compatibility with existing 5 V logic systems.

FAQ

What logic family does SN74H102N belong to, and how does it differ from 74LS or 74F variants?

SN74H102N belongs to the original 74H (High-Speed TTL) family. It delivers faster speed than standard 74-series (15 ns vs. 22 ns) but consumes more power than 74LS. Unlike 74F, SN74H102N lacks Schottky clamping, resulting in higher saturation delay. SN74H102N maintains full pin and functional compatibility with other 74xx-series 14-pin DIP NOR gates, though timing and drive specs differ.

Is SN74H102N suitable for new designs, or is it intended only for legacy repair?

SN74H102N is primarily intended for legacy system repair and obsolescence mitigation. While fully functional, its higher power consumption and lack of modern packaging options make it less optimal for new low-power or space-constrained designs. Aetrix Electronics stocks SN74H102N specifically to support long-lifecycle industrial and defense programs where form-fit-function replacement is mandatory.

Does SN74H102N have open-collector outputs?

No, SN74H102N features standard totem-pole (push-pull) outputs-not open-collector. This means each output actively drives both high and low states, eliminating the need for external pull-up resistors. The totem-pole configuration supports direct interfacing with other TTL inputs but prevents wired-AND configurations without additional discrete components.

What is the maximum recommended capacitive load for SN74H102N outputs?

The maximum recommended capacitive load for SN74H102N outputs is 15 pF, as specified in the original TI datasheet and verified in Rochester Electronics' test program. Exceeding this value increases propagation delay nonlinearly and may cause marginal timing in high-frequency applications. For loads >15 pF, buffer staging or transmission line termination should be considered.

How is the Rochester Electronics version of SN74H102N qualified for military use?

The Rochester Electronics version of SN74H102N is qualified to MIL-PRF-35835 Class Q (Qualified Manufacturers List) and certified to AS9120 and ISO-9001 standards. It undergoes testing using original TI factory test programs or Rochester-developed equivalents, ensuring compliance with the original OEM electrical and timing specifications-including extended burn-in and parametric screening for military avionics spares.