Texas Instruments SNJ54HC112J

Overview

SNJ54HC112 from Texas Instruments is a dual J-K negative-edge-triggered flip-flop with independent preset (PRE) and clear (CLR) inputs, operating across 2V–6V supply range. It delivers 13ns typical propagation delay at 6V, ±4mA output drive, 40μA max ICC, and supports 29MHz clock frequency. It serves in military-grade timing control circuits requiring robust asynchronous set/reset and edge-triggered state storage.

For engineers reviewing the SNJ54HC112 datasheet, SNJ54HC112 pinout, SNJ54HC112 application, or SNJ54HC112 equivalent, key selection criteria include its −55°C to +125°C operating range, CDIP-16 hermetic package, negative-edge clocking behavior, guaranteed setup/hold timing under worst-case military conditions, and compatibility with LSTTL loads.

Technical Context

The SNJ54HC112 implements two fully independent J-K flip-flops sharing no internal logic-each with dedicated PRE, CLR, CLK, J, K, Q, and Q̅ terminals. Triggering occurs exclusively on the negative-going edge of CLK, with asynchronous PRE/CLR overriding all synchronous inputs regardless of clock state.

Its CMOS architecture ensures rail-to-rail output swing, low input current (≤1μA), and immunity to floating inputs when unused pins are tied high/low per TI SCBA004 guidance. The device meets MIL-PRF-38535 Class B requirements and is characterized for full parametric performance across −55°C to +125°C.

Key Specifications

Pinout & Package

SNJ54HC112 is supplied in a 16-pin Ceramic Dual In-line Package (CDIP-J), hermetically sealed with 0.300-inch body width and 0.100-inch lead pitch. Package dimensions: 19.56mm × 6.92mm (including leads), body size 19.56mm × 6.92mm. RoHS-exempt, SNPB lead finish, non-RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SNJ54HC112, SNJ54LS112J trades power efficiency and voltage flexibility for TTL compatibility, while SNJ54ACT112J improves speed and quiescent current but demands tighter signal integrity controls-making SNJ54HC112 the optimal balance of ruggedness, versatility, and legacy interoperability in harsh-environment digital control.

Availability

SNJ54HC112 is available at Aetrix Electronics and suitable for avionics timing control, secure communication modems, ruggedized motor drive logic, and spacecraft onboard computers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SNJ54HC112 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 delivering analog, embedded processing, and logic solutions with emphasis on reliability, longevity, and military-grade qualification.

The SNJ54HC112 belongs to TI's 54HC logic family-designed specifically for high-reliability defense, aerospace, and industrial applications where extended temperature operation, hermetic packaging, and MIL-PRF-38535 compliance are mandatory.

FAQ

What is the maximum clock frequency supported by SNJ54HC112 at −55°C?

At −55°C and VCC = 6V, SNJ54HC112 supports a maximum clock frequency of 20MHz per the SN54HC112 characterization data. This derating from the 29MHz typical value at 25°C ensures timing margin under worst-case cold-start conditions in aerospace deployments. The device maintains full functionality across its entire −55°C to +125°C range without configuration changes.

Does SNJ54HC112 require external pull-up resistors on PRE and CLR inputs?

No, SNJ54HC112 does not require external pull-up resistors on PRE and CLR inputs. These inputs are active-low and internally compatible with CMOS logic levels; however, TI mandates that all unused inputs-including PRE and CLR when not actively driven-must be tied to VCC or GND to prevent floating states and undefined operation per application report SCBA004.

Can SNJ54HC112 operate reliably at 2.5V supply voltage?

Yes, SNJ54HC112 operates reliably at 2.5V supply voltage. Its specified 2V–6V range includes full parametric compliance at 2.5V: tpd = 54ns (max), fclock = 5MHz (min), and VIH/VIL thresholds scale proportionally. This makes SNJ54HC112 suitable for mixed-voltage systems interfacing with 2.5V FPGAs or microcontrollers without level translation.

Is SNJ54HC112 pin-compatible with SN74HC112N?

SNJ54HC112J and SN74HC112N share identical 16-pin DIP pinouts and logic functions, but differ in temperature range, packaging, and qualification. SNJ54HC112J uses hermetic CDIP with −55°C to +125°C rating and MIL-PRF-38535 Class B screening, while SN74HC112N is plastic PDIP rated −40°C to +85°C. PCB layout is mechanically interchangeable, but thermal and reliability requirements dictate material selection.

What is the meaning of "SNJ" prefix in SNJ54HC112J?

The "SNJ" prefix in SNJ54HC112J denotes a Texas Instruments military-grade part meeting JAN (Joint Army-Navy) specifications and processed under MIL-PRF-38535. It signifies full traceability, extended temperature qualification (−55°C to +125°C), hermetic CDIP packaging, and screening for defense/aerospace use-distinct from commercial "SN74" or standard "SN54" variants.