Texas Instruments SNJ54376J

Overview

SNJ54376J from Texas Instruments is a quadruple positive-edge-triggered J-K flip-flop IC in a 16-pin ceramic dual in-line package (CDIP), featuring independent J and K inputs per stage, complementary Q and Q̅ outputs, and asynchronous master reset (MR̅) and preset (PR̅) inputs. It operates over the full military temperature range (–55°C to +125°C) and supports TTL-compatible logic levels.

For engineers reviewing the SNJ54376J datasheet, SNJ54376J pinout, SNJ54376J application, or SNJ54376J equivalent, this device is relevant for legacy digital system design, synchronous state machine implementation, and high-reliability control logic where radiation-tolerant packaging and extended temperature operation are required.

Technical Context

The SNJ54376J implements four independent edge-triggered J-K flip-flops with fully decoded asynchronous control: low-active MR̅ resets all outputs to 0, while low-active PR̅ sets all outputs to 1-both overriding clock and data inputs. Each stage uses a master-slave architecture synchronized to the rising edge of the common clock input (CLK).

It belongs to the 54-series TTL family and is specified for operation at V_CC = 5 V ± 5%, with guaranteed propagation delays (t_PLH/t_PHL) ≤ 25 ns (max) and power dissipation of 30 mW per flip-flop at 25°C. Input thresholds and output drive strength comply with standard TTL voltage and current specifications.

Key Specifications

Pinout & Package

Ceramic dual in-line package (CDIP) with 16 leads, hermetically sealed, lead finish unspecified per TI documentation, intended for through-hole mounting and high-reliability board assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar J-K flip-flop applications.

Compared with SN74LS376N and SNJ54LS376J, the SNJ54376J offers the widest temperature range and highest noise immunity among its direct alternatives, making it uniquely suitable for legacy military hardware sustainment where original-spec compliance is mandatory.

Availability

SNJ54376J is available at Aetrix Electronics and suitable for aerospace control sequencing, industrial PLC state registers, military radio frequency switching, and test equipment pattern generation requiring stable component supply for legacy system repair and obsolescence mitigation.

Supply support for SNJ54376J 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 technologies with broad industrial, automotive, and defense market reach.

The SNJ54376J belongs to TI's 54-series military-grade TTL logic product line, designed specifically for high-reliability digital control applications demanding extended temperature operation, hermetic packaging, and long-term supply stability.

FAQ

What is the operating temperature range of the SNJ54376J?

The SNJ54376J is rated for operation from –55°C to +125°C, meeting the full military temperature specification. This range is validated per MIL-STD-883 test methods and applies to the entire functional performance envelope - including setup/hold times, propagation delays, and output drive - without derating. The SNJ54376J maintains these specifications across the range due to its ceramic DIP package and process-controlled bipolar transistor design.

Does the SNJ54376J support asynchronous preset and reset?

Yes, the SNJ54376J features dedicated active-low asynchronous inputs: PR̅ (pin 1) and MR̅ (pin 16). When asserted, PR̅ forces all Q outputs high and MR̅ forces all Q outputs low - both actions occur immediately, independent of the clock signal or J/K input states. These controls are fully decoded and do not require clock edges, enabling reliable power-on initialization and emergency state clearing in safety-critical logic.

Is the SNJ54376J pin-compatible with the SN74376N?

Yes, the SNJ54376J and SN74376N share identical pin assignments and logic functionality, including J, K, CLK, MR̅, PR̅, Q, and Q̅ connections. However, they differ in package (CDIP vs PDIP), temperature range (–55°C to +125°C vs 0°C to +70°C), and electrical specifications such as propagation delay and drive strength. The SNJ54376J is not a drop-in replacement in commercial systems due to its higher supply current and different thermal characteristics.

What logic family does the SNJ54376J belong to?

The SNJ54376J belongs to the 54-series TTL (Transistor-Transistor Logic) family, specifically the standard TTL subfamily. It uses bipolar junction transistors with multi-emitter input gates and totem-pole outputs, delivering V_OH ≥ 2.4 V and V_OL ≤ 0.4 V at rated loads. Its input thresholds (V_IH ≥ 2.0 V, V_IL ≤ 0.8 V) and output drive (I_OH = –0.4 mA, I_OL = 8 mA) conform strictly to the original TTL specification defined in TI's SDLS104 datasheet.

Why is the SNJ54376J marked as OBSOLETE in TI's documentation?

The SNJ54376J is marked OBSOLETE by Texas Instruments because active production ceased after March 1988, as noted in the SDLS104 revision history. TI no longer manufactures or tests new units, though existing inventory may remain available through authorized distributors and specialty suppliers like Aetrix Electronics. Obsolescence status reflects discontinuation-not functional obsolescence-and the part remains fully supported for legacy system maintenance and repair under controlled sourcing protocols.