onsemi MC14042BDG

MC14042BDG Quad Transparent Latch Product Summary

The MC14042BDG by onsemi is a Quad Transparent Latch IC housed in a 16-pin SOIC package (case 751B). Designed using a monolithic structure that integrates both P-channel and N-channel MOS enhancement mode devices, the MC14042BDG provides four independently controlled D-type transparent latches, each with its own data input and a shared clock. The device is engineered for applications requiring reliable latching and data transfer functions, with built-in features to maximize flexibility and protect circuit integrity. Such latches are commonly employed in buffer registers, temporary data storage, and control signal sequencing within digital logic designs.

Main Attributes and Functional Capabilities of the MC14042BDG

The MC14042BDG showcases several vital features tailored to modern logic circuit design:

Buffered data inputs ensure signal integrity and noise resistance.

All four latches are controlled via a common clock input, streamlining timing coordination.

The clock polarity control allows dynamic selection of data transfer based on logic state; with polarity low, data latching occurs on the clock’s low level, while with polarity high, transfer occurs on the clock’s high level.

Both Q and $\overline{Q}$ outputs are provided per latch for flexible logic architectures.

Double diode input protection guards against damaging electrostatic discharge and excessive voltages.

Wide supply voltage range, supporting operation from 3.0 Vdc to 18 Vdc, enables adaptability in different circuit environments.

Capable of driving two low-power TTL loads or one low-power Schottky TTL load over its full rated temperature range.

The MC14042BDG is Pb-Free and RoHS compliant, aligning with environmental and safety standards.

For automotive and specialized applications, devices with the NLV prefix are available and qualified to AEC–Q100/PPAP standards.

Electrical Specifications and Usage Guidelines for the MC14042BDG

The MC14042BDG is designed for consistent operation across a range of voltages and environmental conditions. Maximum ratings protect the device’s reliability, with careful attention required to avoid stress outside specified limits, such as overvoltage or excess temperature. Input and output voltages must always be within the device’s supply rails ($V_{SS}$ ≤ $V_{in}$/$V_{out}$ ≤ $V_{DD}$) to maintain proper functionality. As with all CMOS logic devices, unused inputs should be connected to defined logic levels (either $V_{SS}$ or $V_{DD}$) to prevent erratic behavior.

The device incorporates static protection circuitry; nevertheless, robust ESD handling practice is recommended during board assembly and installation. For temperature management, the “D/DW” package rating specifies a thermal derating factor of -7.0 mW/°C from 65°C to 125°C, which should be considered in high-density or high-temperature applications.

MC14042BDG Switching Behavior and Timing Evaluation

Switching characteristics of the MC14042BDG are determined by the interaction of clock input, polarity selection, and output timing. The device provides formulas to estimate supply current as a function of capacitive load, supply voltage, and operating frequency:

$$

\mathsf{I}_{\mathsf{T}}(\mathsf{C}_{\mathsf{L}}) = \mathsf{I}_{\mathsf{T}}(50~\mathsf{pF}) + (\mathsf{C}_{\mathsf{L}} - 50)~\mathsf{Vfk}

$$

where $I_T$ is in $\mu$A per package, $C_L$ (in pF) is the output load capacitance, $V$ is $(V_{DD} - V_{SS})$ in volts, $f$ is input frequency in kHz, and $k=0.004$.

The MC14042BDG’s AC performance is characterized using standardized test circuits and timing diagrams, making it suitable for use in moderate-speed logic chains and synchronous control systems. For timing design, reference diagrams for both "data to output" and "clock to output" transitions provide clear guidance for system-level integration. As with all CMOS latches, actual switching performance may vary with supply voltage, temperature, and load conditions; design engineers should verify timing against their specific use case requirements.

Physical Specifications and Package Information for the MC14042BDG

The MC14042BDG is delivered in a 16-lead SOIC package, with nominal dimensions of 9.90 mm × 3.90 mm × 1.37 mm and a 1.27 mm pin pitch. The mechanical specification adheres to ASME Y14.5M, 2018 standard for tolerancing and dimensioning. This compact, surface-mount package is well suited for dense PCB layouts, automated pick-and-place manufacturing, and thermal management in modern electronic designs. Mold protrusion and dam-bar allowances are accounted for in the package specification, ensuring reliable solder mounting and electrical connection.

For designers working with reflow soldering or other automated processes, onsemi provides guidance on Pb-Free strategies and soldering details in their reference documentation, promoting best practices in long-term reliability and process yield.

MC14042BDG Identification Marks and Labeling Instructions

For accurate component identification, the MC14042BDG features a standard marking diagram that encodes device type code, assembly location, wafer lot, manufacturing year/week, and Pb-Free indicator. This structured marking enables traceability for quality assurance and supply chain management. When inspecting incoming components or performing failure analysis, engineers can use the marking to cross-reference production lot details with supplier documentation. Some package variants may display the Pb-Free indicator as either “G” or a microdot.

Alternative and Substitute Options for the MC14042BDG

When considering alternatives or replacements for the MC14042BDG, engineers should prioritize compatibility in functionality, electrical characteristics, and mechanical footprint. Equivalent models should be quad D-type transparent latches with similar supply voltage, output drive capacity, and SOIC-16 packaging. Manufacturers like Texas Instruments, Nexperia, and other major CMOS logic providers offer compatible devices, such as their respective CD4042B or 74HC/HCT4042 series. Selection should be validated against required parameters including clock polarity control, output configuration (Q/$\overline{Q}$), and required qualification standards (e.g., automotive AEC–Q100).

Conclusion

: Engineering Value of MC14042BDG Quad Transparent Latch

The onsemi MC14042BDG delivers robust, versatile quad transparent latch functionality in a compact SOIC-16 package, optimized for demanding digital logic applications spanning industrial, automotive, and consumer domains. With its buffered inputs, flexible clock polarity control, wide operating voltage range, and proven environmental compliance, the MC14042BDG stands as a reliable choice for new board designs and maintenance of existing systems. Careful attention to electrical, timing, and mechanical considerations will ensure its successful integration into a variety of digital architectures. The availability of equivalent models further supports long-term design resilience and procurement flexibility for product selection engineers and sourcing professionals.