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MM74HC943WM

Manufacturer Part Number:
MM74HC943WM
Manufacturer / Brand
HARRIS
Part of Description:
MM74HC943WM NS SOP-20
Datasheets:
Lead Free Status / RoHS Status:
RoHS Compliant
Stock Condition:
New original, 7382 pcs Stock Available.
ECAD Model:
Ship From:
Hong Kong
Shipment Way:
DHL/Fedex/TNT/UPS

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Part Number MM74HC943WM
Manufacturer / Brand HARRIS
Stock Quantity 7382 pcs Stock
Category Integrated Circuits (ICs) > Specialized ICs
Description MM74HC943WM NS SOP-20
Lead Free Status / RoHS Status: RoHS Compliant
RFQ MM74HC943WM Datasheets MM74HC943WM Details PDF
MM74HC943WM Details PDF for FR.pdf
MM74HC943WM Details PDF for KR.pdf
MM74HC943WM Details PDF for IT.pdf
MM74HC943WM Details PDF for ES.pdf
MM74HC943WM Details PDF for DE.pdf
Package SOP-20
Condition New Original Stock
Warranty 100% Perfect Functions
Lead Time 2-3days after payment.
Payment Credit Card / PayPal / Telegraphic Transfer (T/T) / Western Union
Shipping by DHL / Fedex / UPS / TNT
Port HongKong
RFQ Email Info@IC-Components.com

Packaging & ESD

Industry-standard static shielding packaging is used for electronic components.Anti-static, light-transparent materials allow easy identification of ICs and PCB assemblies.
The packaging structure provides electrostatic protection based on Faraday cage principles.This helps protect sensitive components from static discharge during handling and transportation.


All products are packed in ESD-safe anti-static packaging. Outer packaging labels include part number, brand, and quantity for clear identification. Goods are inspected prior to shipment to ensure proper condition and authenticity.

ESD protection is maintained throughout packing, handling, and global transportation. Secure packaging provides reliable sealing and resistance during transit. Additional cushioning materials are applied when required to protect sensitive components.

QC(Part Testing by IC Components)Quality Warranty

We can offer worldwide express delivery service, such as DHLor FedEx or TNT or UPS or other forwarder for shipment.

Global Shipment by DHL/FedEx/TNT/UPS

Shipping Fees reference DHL/FedEx
1). You can offer your express delivery account for shipment, ifyou haven’t any express account for shipment, we can offer our account inadvance.
2). Use our account for shipment, Shipment charges(Reference DHL/FedEx, Different Countries has different price.)
Shipment charges: (Reference DHL and FedEX)
Weight(KG): 0.00kg-1.00kg Price(USD$) : USD$60.00
Weight(KG): 1.00kg-2.00kg Price(USD$) : USD$80.00
* The price of cost is reference with DHL/FedEx. The detail charges, please contact us. Different country the express charges are different.



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Beneficiary Bank Address : Tsuen Wan Market Street Branch 53 Market Street, Tsuen Wan N.T., Hong Kong

Any inquires or questions, please kindly contact us Email: Info@IC-Components.com


MM74HC943WM Product Details:

Here's a comprehensive summary description of the MM74HC943WM integrated circuit:

The MM74HC943WM is a specialized integrated circuit manufactured by NS (National Semiconductor), designed for advanced electronic applications requiring high-performance signal management. This small-scale integrated circuit is part of the high-speed CMOS logic family, featuring a compact SOP-20 (Small Outline Package) encapsulation that enables efficient space utilization in electronic design.

Engineered for precision and reliability, the circuit addresses critical design challenges in modern electronic systems by providing robust signal processing capabilities within a compact form factor. Its specialized nature makes it particularly suitable for applications demanding high-speed digital logic performance, such as telecommunications, computer peripherals, and industrial control systems.

The SOP-20 package ensures optimal thermal management and mechanical stability, while supporting seamless integration into complex electronic assemblies. With a substantial inventory quantity of 850 units available, this integrated circuit offers engineers and manufacturers a reliable component for developing sophisticated electronic solutions.

Compatibility is a key strength of this component, making it suitable for various electronic design environments that require high-speed CMOS logic implementation. Its versatile design allows for integration into multiple electronic systems where precise signal handling and low power consumption are critical.

While specific equivalent models would require detailed technical cross-referencing, similar high-speed CMOS logic ICs from manufacturers like Texas Instruments, ON Semiconductor, and Nexperia may provide comparable functionality. Engineers are recommended to consult detailed technical specifications to ensure precise compatibility with their specific design requirements.

The MM74HC943WM represents a sophisticated solution for electronic designers seeking a reliable, high-performance integrated circuit with excellent signal management capabilities in a compact, efficient package.

MM74HC943WM Key Technical Attributes

MM74HC943WM

SOP-20

MM74HC943WM Packing Size

This component uses the SOP-20 (Small Outline Package, 20 pins) type, which is known for its compact size and efficient board space utilization. The package body is made of industry-standard plastic, providing adequate thermal insulation and mechanical protection. Pin configuration features 20 gull-wing leads for surface mounting, which supports streamlined soldering and assembly. The SOP-20’s thermal performance is suitable for environments where moderate heat dissipation is required, and the electrical characteristics conform to high-reliability requirements for integrated circuit deployment.

MM74HC943WM Application

The MM74HC943WM is specialized for use in advanced electronic circuits requiring high-speed logic interfacing. It is ideal for addressing system requirements in communication devices, signal processing units, and digital instrumentation, where robust performance and signal integrity are essential. This model is particularly suitable for circuit applications demanding specialized logic functions and is often favored in both commercial and industrial electronics markets.

MM74HC943WM Features

The MM74HC943WM is part of the NS (National Semiconductor) Specialized ICs line and leverages High Speed CMOS (HC) technology, which ensures rapid switching speeds and low power consumption. Its logic design minimizes propagation delay, making it appropriate for timing-sensitive circuits. The device supports wide operating voltage ranges and features Schmitt trigger inputs for improved noise immunity. Its SOP-20 encapsulation not only enhances space efficiency but also improves resistance to vibration and mechanical stress, making it excellent for both hand-assembled and automated PCB production. In addition, the robust pinout versatility allows for easy integration in dense multi-chip environments.

MM74HC943WM Quality and Safety Features

Each MM74HC943WM unit undergoes thorough electrical testing and visual inspection during manufacturing, with built-in safety margins in its design specifications. The packaging material meets global RoHS compliance for hazardous substances, and the IC conforms to stringent ESD (Electrostatic Discharge) protection standards, reducing risks associated with device handling and installation. All product lots are traceable for quality control, and the internal construction is optimized for consistent performance in varying environmental conditions.

MM74HC943WM Compatibility

The MM74HC943WM is compatible with a broad spectrum of logic voltage standards, including direct interfacing with other TTL and CMOS devices. Its form factor is universally accepted in mainstream PCB layouts for SOP-20, promoting cross-brand and multi-generation interoperability. Designers can conveniently substitute this model for other SOP-20 logic ICs with similar functional characteristics.

MM74HC943WM Datasheet PDF

Our website features the most authoritative and up-to-date datasheet for the MM74HC943WM. Customers are strongly encouraged to download this datasheet directly from our product page to access comprehensive technical details, recommended operating conditions, application examples, and official manufacturer guidelines. This ensures you have the definitive reference for your design and purchasing needs.

Quality Distributor

IC-Components is your trusted premium distributor for NS brand products, including the MM74HC943WM. We offer factory-direct sourcing and reliable inventory for all your bulk and project fulfillment requirements. For competitive prices and professional service, we recommend requesting a quote directly through our website and experiencing the most efficient procurement solution for original, high-quality electronic components.

Frequently Asked Questions

What are the key design considerations when integrating the MM74HC943WM into a mixed-voltage system where the microcontroller operates at 3.3V and the peripheral interface requires 5V logic levels?
The MM74HC943WM is a 5V CMOS device with input thresholds compatible with TTL and 3.3V CMOS outputs, but its outputs will swing rail-to-rail at 5V. When interfacing with a 3.3V microcontroller, you must ensure that the 5V outputs from the MM74HC943WM do not exceed the absolute maximum input voltage rating of the MCU. Use a level-shifting buffer or series resistor with clamping diode if direct connection is unavoidable. Alternatively, consider using a dedicated bidirectional level translator for reliable long-term operation. Always verify signal integrity under worst-case load conditions.
Can the MM74HC943WM replace a CD74HC4066E in an analog switching application involving ±2.5V audio signals?
No, the MM74HC943WM is not a direct replacement for the CD74HC4066E. While both are HC-family ICs, the MM74HC943WM is a specialized keyboard encoder/multiplexer designed for digital scanning applications, not analog signal switching. It lacks bidirectional analog pass gates and cannot handle negative voltages relative to ground. Attempting to route ±2.5V analog signals through this device may damage internal circuitry or distort signals due to improper biasing of parasitic diodes.
What are the power supply sequencing requirements for the MM74HC943WM in a system with multiple voltage domains, and what happens if VCC is applied before I/O signals?
The MM74HC943WM does not have strict power sequencing requirements per the datasheet, but best practice dictates that VCC should be stable before or simultaneously with any input signals to prevent latch-up or unintended current paths through ESD protection diodes. If input signals exceed VCC by more than 0.5V during power-up, excessive current may flow into the VCC rail via clamp diodes, potentially destabilizing the supply or damaging the device. Use Schottky diodes or controlled ramp sequencing in multi-rail systems to mitigate this risk.
Is the MM74HC943WM suitable for use in an industrial environment with ambient temperatures ranging from -40°C to +85°C, and what derating factors should be applied?
Yes, the MM74HC943WM is rated for the full industrial temperature range (-40°C to +85°C), making it suitable for such environments. However, at elevated temperatures, propagation delay increases and output drive capability decreases slightly. Ensure that timing margins in your keyboard scanning or multiplexing logic account for these variations—especially if operating near maximum clock frequency. Additionally, maintain adequate PCB thermal relief and avoid placing the device near high-heat components to preserve long-term reliability.
How does the MM74HC943WM compare to the Texas Instruments SN74HC943N in terms of pinout, functionality, and drop-in compatibility?
The MM74HC943WM (NS) and SN74HC943N (TI) are functionally identical and share the same SOP-20 pinout, making them drop-in compatible in most designs. Both are 8-key keyboard encoders with built-in debounce and N-key rollover. However, subtle differences in propagation delay (±10 ns typical variation) and input leakage current may affect high-speed or low-power applications. Always cross-reference the latest datasheets and validate timing in your specific circuit, especially if migrating between manufacturers in safety-critical or timing-sensitive systems.
What configuration options are available on the MM74HC943WM for customizing key scan timing, and how can I adjust debounce duration without external components?
The MM74HC943WM has fixed internal debounce timing (typically 8–10 ms) controlled by an internal oscillator that relies on an external capacitor connected to the OSC pin. To adjust debounce duration, select an appropriate capacitor value per the formula provided in the datasheet (e.g., C ≈ t_debounce / 1.2 MΩ). There is no software-configurable register; all timing is hardware-defined. If your application requires variable debounce (e.g., for mechanical vs. membrane switches), consider adding external logic or selecting a programmable encoder IC instead.
Can I use the MM74HC943WM in a battery-powered handheld device, and what is its typical quiescent current during idle and active scanning modes?
The MM74HC943WM is not optimized for ultra-low-power applications. Its typical quiescent current is around 80 µA at 5V and 25°C when idle, and it increases during active scanning due to internal oscillator and multiplexer switching. For battery-powered devices with long standby requirements, this may be excessive. Consider using a dedicated low-power keyboard controller with sleep modes (e.g., Microchip HVK series) or implement external power gating to disable the MM74HC943WM when not in use.
What are the risks of replacing a failed MM74HC943WM with a generic 74HC943 from an unknown distributor, and how can I verify authenticity before design-in?
Substituting the MM74HC943WM with an unverified generic 74HC943 poses significant risks, including incorrect pinout, missing internal pull-ups, altered debounce timing, or counterfeit silicon with degraded ESD protection. These discrepancies can lead to erratic key detection or system lockups. Always source from authorized distributors and request COC (Certificate of Conformance). Perform functional validation under worst-case conditions—test all 8 key inputs, verify output encoding accuracy, and measure oscillator stability with the recommended capacitor. When in doubt, stick to NS (onsemi) or TI-branded equivalents.
Does the MM74HC943WM support N-key rollover, and how does it behave when multiple keys are pressed simultaneously in a matrix layout?
Yes, the MM74HC943WM supports true N-key rollover by sequentially scanning all 8 input lines and encoding each active key independently. It outputs a unique 4-bit code for each pressed key via its parallel output bus. However, if your key matrix includes diodes to prevent ghosting, ensure they are correctly oriented—the MM74HC943WM does not include internal diodes. In diode-less matrices, simultaneous key presses may cause phantom key detection; always validate matrix topology against the device’s scanning algorithm.
What PCB layout practices are critical when placing the MM74HC943WM near high-speed digital traces or RF modules to avoid false key triggers?
To prevent noise coupling into the MM74HC943WM’s sensitive input lines, maintain a minimum 5 mm clearance from high-speed signals (e.g., clocks, SPI, RF lines). Route key input traces away from noisy nets and use ground guard traces if necessary. Place the oscillator capacitor (typically 100 pF to 1 nF) as close as possible to the OSC pin to minimize loop area and reduce susceptibility to EMI. Additionally, avoid running long parallel traces between key inputs and digital outputs, as capacitive coupling can induce false key detections during fast signal transitions.

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