In the present digital age, the general populace is ever reliant on a mix of electronic products to get by each day – products that pack a host of electronic components that connect, communicate and ‘collaborate’. From smartphones to servers, air-conditioners to automobiles, these products necessitate the use of interconnects, antennas, sensors, capacitive switches and more. But that’s not all. Manufacturers of these devices require performance requirements and specifications to be met that include reliability, user safety, usability and the list goes on. The features, functions and ‘Fitness’ of electronic interconnects used in their respective applications pivot significantly on their manufacturer’s design experience, quality and manufacturing technologies. This article discusses some characteristics and capabilities of one of Molex’s most successful and best-selling family of interconnects – the Fit Power Connector family.
Global shifts in a digitally transformed world drive the need for more ‘power’
In recent years, the world has faced unprecedented challenges, leading to disruptions affecting the global supply chain and their tributary operations in logistics, sourcing and manufacturing. Revisions to work-from-home policies implemented across regions in response to the global pandemic led manufacturers, distributors and suppliers to redraw their supply chain map and reshuffle original production plans and output. The urgent need for medical breathing and monitoring apparatus created unprecedented demand for electronic components and connectors used to power up these machines. Having a comprehensive product portfolio to meet different industry application needs gives companies like Molex good market positioning as a global supplier of power interconnects.
Taking a forward-looking perspective, it is obvious how quickly the advancements in Big Data, Edge Computing, Artificial Intelligence (AI), and Next-Generation Radio Access Networks (RAN) technologies transformed the entire technology ecosphere. Technology service providers in the telco industry are relentlessly evolving to capture value by seeking out game-changing use cases for their products and applications - as are their competing cloud-solution providers. The global race for the cutting-edge 6G technology has led industry experts all over the world to discuss the development and vision of 6G, with focus on how 6G, as the super infrastructure of the future digital world, can achieve the ultimate blend of performance, connectivity, computing, intelligence and security. The call for a unified 6G innovation system to be established presents tremendous opportunity for power products supporting 6G.
Regardless of the growing variety of applications AI and digital transformations of sorts have brought about, one thing remains the same - power interconnect solutions are central and critical to the need for power, more power and higher power. The growing dependance on an uninterrupted supply chain for power products is intertwined with Molex’s launch of new product innovations, enhancements and extensions to its Fit Power connector families. Industry-proven reliability, protection and ease of use – whether in servers, switches or distributed power supplies or HVAC cooling systems - are exemplary testaments to Molex’s success in expanding this family of connectors over the decades, bringing value to the customers using them.
As electronic devices become smarter, their design challenges increase
The demand for more and ‘smarter’ electronic devices brought transformations to practically every aspect of our lives. Several years from the pandemic, we see changes implemented to improve public health and hygiene. Typical examples include facility management with elevated hygiene and sanitation standards. Traditional soap dispensers gave way to hands-free, contactless versions that dispense liquid soap based on sensor detections. Sensor-based faucets and hand-towel dispensers are used in schools, commercial buildings and shopping malls and these require power to run. The gradual reopening of more businesses accompanied the surge in investments made in products such as Infra-red thermal scanners as well as thermometers for temperature monitoring in airport checkpoints and hospitals during the pandemic years.
The home energy storage market is rapidly evolving, driven by a surge in demand for safe and efficient energy solutions. This growth emphasizes the need for addressing increased power requirements along with robust thermal management. Designers face the challenge of optimizing for power within the constrained spaces of residential settings, requiring innovative approaches to printed circuit board (PCB) space utilization and connectivity design.
The impact of these shifts resonates with the core of product manufacturing that involved many aspects of engineering design, whether seen or unseen. Design engineers were challenged with connectivity issues associated with power, which depending on the application, could include crosstalk or EMI/RFI, terminal back-outs, cross-mating errors and connector detachment, to name a few.
Finding connectors with the right ‘Fit’ can help overcome product design challenges
Across industries, regardless of application, electrical disruptions caused by mechanical disconnects during mission-critical operations can be a serious problem. Whether the disruption is in the supply of current to power sources of hospitals or high-speed train control panels, the reliability of the interconnects used is crucial. Molex’s Fit series of connectors helps eliminate disruptions caused by terminal back-outs or improperly positioned electrical contacts within the connector system. Products such as Nano-Fit, Micro-Fit / Micro-Fit+, Ultra-Fit, Mini-Fit and Mega-Fit connectors provide Terminal Position Assurance (TPA) features that ensure terminals are fully seated in the housing, reducing terminal back-out. If the main retention feature fails, the terminal is retained, which improves assembly quality, avoiding rework and saves costs. This is a simple but significant feature in power interconnects. Smart factories that deploy hundreds of robotic arms to weld, assemble or inspect vehicle parts can little afford power-related disruptions throughout the vehicle processing line. The cost of disruptions to operations of this nature is infinitely higher than the collective price of all connectors put together in the making of power supplies used in smart factories. Molex’s enhanced TPA design of Fit connectors supports high mating cycles in highly automated assembly operations. This feature favors connector assembly processes which are heavily manual. Fit Power connectors with added TPAs minimize operator fatigue as well as human errors involved in manual connection of connectors to cable assemblies.
Design engineers designing higher current applications often need a good mix of connectors with a broad range of current ratings to match various current requirements of an application. Added to this may be the need to pack more electronics into tighter physical spaces within the application as well. Finding the right fit is easy with Molex’s Fit family of power connectors as there are common features across different families (such as isolated contacts, low mating force locking latches etc.) and these families feature a wide range of current ratings. The Micro-Fit+ for example, offers current as low as 1 Amp while a Mega-Fit connector supports current as high as 30 Amps per contact. Nano-Fit, Micro-Fit, and Mini-Fit power connectors provide design engineers with fully protected header terminals.
In regions such as Europe, where electrical safety standards need to be met, Molex offers Fit connectors that use V-0/Glow Wire combination resin which reduces material and labor costs. The Micro-Fit+ Connector System is one such family. This glow wire capable wire-to-wire and wire-to-board system features a 3.00mm pitch, supports current ratings of up to 13.0 A and offers superior design options for flexibility and efficient assembly. The Mega-Fit as well as the Mini-Fit Versa connector families offer new UL 94 V-0, Glow Wire Combination housing material for applications that require to pass Glow-Wire Test requirements.
Several products within the Fit family also feature polarized housings in different colors and tangless terminals. The Ultra-Fit Power Connectors deliver color-coding and keying options that eliminate same-circuit-size mis-mating and offer the tangless feature that allows the terminal locking mechanism to be incorporated into the receptacle housing. Nano-Fit, the smallest, fully-isolated headers in the market that deliver up to 69% more PCB space in the x-axis than competing connectors, offer multiple mechanical keying and color-coded options. Same-circuit, multiple-connector use with virtually no chance of cross-mating and color-coding visual indication of proper mating connector enables faster assembly with this family. The Mini-Fit Versa family offers five color options for quick connector identification and ease of assembly.
As with any process, misalignment is a common problem but can be prevented. Molex’s Fit Power connectors include polarization and keying features that virtually eliminate misalignment problems, significantly reducing the errors that result in improper installation. Furthermore, Molex Fit series connectors support multiple contact points, providing various critical contact points between terminal and mating contact points. Compared to contact systems with fewer or only two paths, multiple current paths offer significant advantages of improved electrical contact and end-product reliability.
Another outstanding feature of Molex’s Fit family of connectors is its support for tangless terminals. This feature protects the terminals of manufacturers and cable harness assembly teams during the packaging and assembly insertion processes. It saves both time and money by reducing failures associated with electrical terminal lock wings. Molex Fit series connectors also support reflow-capable headers, which reduce processing requirements and costs. Reflow soldering is reliable and effective for leads and pads of all pitches, enabling the production of very high-quality circuit boards.
Infographic: Micro-Fit versus other Fit family connector assembly dimensions
Overview of Fit family products
Molex’s Fit family of power connectors includes Nano-Fit, Micro-Fit, Micro-Fit+, Ultra-Fit, Mini-Fit, Mini-Fit Sigma, Mini-Fit Sigma Sealed, Mini-Fit Max and Mega-Fit.
Table: Core specifications of 5 main Fit Power Connector families
NANO-FIT
The smallest fully isolated header in the market, this Wire-to-Wire and Wire-to-Board connector provides a small package that eases space constraints, allowing up to 69% more space in the x-axis than competing connectors. Supporting up to 8.0 A of current, Nano-Fit offers fully protected header terminals, a compact structure and various functional options to ensure correct installation and highly reliable connections in limited spaces. The small-pitch size color coding/keying options ensure correct mating and terminal position assurance (TPA) to reduce terminal back-out. SMT versions of Nano-Fit connectors enable the use of multi-layer PCBs by eliminating the need for through hole drilling while freeing up real estate on space-constricted PCBs. The product potentially reduces costs by enabling use of smaller PCBs with fewer drilled holes.
Nano-Fit Receptacle Housing, TPA Capable, 2.50mm Pitch, Dual Row, 16 Circuits, Black, Glow-Wire Capable (Part No. 105308-1216)
MICRO-FIT
This 3.00mm pitch family of connectors come in a wide range of circuit sizes and cable lengths and support operating temperatures up to 125°C, making Micro-Fit an excellent connectivity solution for power applications - whether in board-to-board, wire-to-board or wire-to-wire configurations. Supporting up to 10.5 A of current, Micro-Fit is available in SMT, press-fit or surface-mount compatible versions, providing design flexibility and options to meet diverse application needs.
Micro-Fit sub-family variants include: Micro-Fit 3.0 Blind-Mate Interface (BMI), Micro-Fit TPA, Micro-Fit 3.0 CPI (Compliant Pin) and Micro-Fit 3.0 RMF (Reduced Mating Force) Terminals.
From left, the above picture shows a Micro-Fit BMI Right Angle, Press-Fit Header (Part No. 447640601) mating with a Micro-Fit BMI Right Angle, Surface Mount Compatible Receptacle (Part No. 444280801)
MICRO-FIT+
The Micro-Fit+ Connector System is a 3.00mm pitch, glow wire capable wire-to-board and wire-to-wire system which offers a higher-current rating of up to 13.0 A and offers reflow options for reduced labor costs, time and resources. The Micro-Fit+ series connects high-current circuits in space-constrained applications with multiple functional options. Based on its unique design, and compared to the standard Micro-Fit 3.0 connectors, the Micro-Fit+ connector’s 40% lower mating force allows for design flexibility, ease of work and reduced operator fatigue during assembly while enhancing assembly efficiency.
An extended family, the Micro-Fit+ Versa Connectors offers a variety of design options which includes polarization and four colors with different keying per color to avoid mis-mating. The product is designed to enhance operational safety and efficient assembly.
New part extensions – the Micro-Fit+ PCIe Connectors offer full PCIe CEM (Card Electromechanical) specification compliance in a compact, space-saving design with hybrid power and signal integration. The Micro-Fit+ PCIe 12V-2x6 Auxiliary Connector System is a CEM (card electromechanical) hybrid solution supporting next-gen PCIe 5.0 and 6.0 applications. This connector and cable offering integrates 12x9.5 A-capable power pins and 4x sideband signal pins in a compact, space-saving design. The latest product family enhancement is 675 W add-in card ready; engineered to dependably handle high power for advanced computing and data processing applications.
ULTRA-FIT
This 3.50mm pitch connector features 17% smaller footprint over similar power connectors, providing PCB space savings with optimized current density. This allows the connector to fit smaller packaging without sacrificing current-carrying capabilities of up to 14.0 A. Multi-color cable configurations with Ultra-Fit TPA Connectors are available off-the-shelf to support development and production programs. Other hallmarks of this family include multiple mechanically keyed color-coded options which allow same-circuit, multiple-connector use with virtually no chance of cross-mating. Ultra-Fit connector’s terminal interface has six independent points of contact (split-box terminal design) providing redundant, secondary current paths for long-term performance and electrical reliability. Ultra-Fit is available in wire-to-wire and wire-to-board configurations. Molex also offers a variant family - the Ultra-Fit Tangless Connectors to meet the need for increased terminal retention.
Ultra-Fit Tangless Receptacle Housing, 3.50mm Pitch, Dual Row, 16 Circuits, Black, Glow-Wire Capable (Part No. 1722583116)
MINI-FIT
Like the Micro-Fit family of connectors, Mini-Fit connectors withstand operating temperatures up to +125°C. Mini-Fit connectors offer double crimping tools, and are available in board-to-board, wire-to-board and wire-to-wire configurations. This 4.20mm pitch connector system delivers 13.0 A of current and supports through-hole and SMT PCB terminations. Molex offers 2-8 circuits solutions for single-row, 2-36 circuits for dual-row designs and supports wire gauge (AWG) of 16-28.
Extended families of Mini-Fit connectors include Mini-Fit BMI, Mini-Fit Versa, Mini-Fit HCS, Mini-Fit Jr., Mini-Fit Sr., Mini-Fit TPA2 and Mini-Fit+ PCIe 5.0 Products.
Dedicated Connectors for Power Applications from Molex | Arrow.com – Mini-Fit
MINI-FIT SIGMA
Mini-Fit Sigma Connectors offer a slim profile and mate with existing Mini-Fit headers, allowing for space savings without changing the bill of materials. These receptacles also include Terminal Position Assurance (TPA) for secure and stable connections to avoid terminal backout issues and provide Glow Wire compatible options to meet the European standard for electrical requirements. Mini-Fit Sigma Connectors overcome many challenges printed circuit board (PCB) designers encounter and provide excellent features for reliability.
Mini-Fit Sigma Sealed Wire-to-Wire Connectors utilize traditional Mini-Fit TPA2 terminals and wire gauges while providing protection from moisture, foam and dust debris ingress. The connector features include panel-mount ears (with recommended panel cut-outs for 0.89mm to 3.00mm thick panels) to provide housing safety and stability. The product includes a rubber seal cap and integral seal cap support on the housing and comes complete with keying and polarization features to ensure accurate mating to standard Mini-Fit 4.2 power connectors. Market applications include home appliances, consumer and commercial systems such as HVACs, air duct machines and industrial automation equipment.
From left to right: The above picture shows the Mini-Fit Sigma Sealed Power Connector system with crimp terminals, rubber cap, TPA feature, panel-mount connector housing with panel-mount ears, keying and polarization features, and panel cut-out.
MINI-FIT MAX
Mini-Fit Max series connectors support end-to-end stacking and offer higher power per unit length and area compared to other mid-range power connectors. This connector offers four independent points of contact providing redundant secondary current paths for long-term electrical performance and reliability. Mini-Fit MAX crimps feature a tangless design to ensure terminal safety during packaging and assembly insertion. The 4.20mm pitch connector supports up to 20.5 A of current and is available in both single- and dual-row configurations. Design versatility, design option availability and durable features make these connectors ideal for both power and signal applications.
Dedicated Connectors for Power Applications from Molex | Arrow.com – Mini-Fit MAX
MEGA-FIT
Power-application customers faced with choosing between headers with exposed terminals that leave connectors susceptible to damage, or large, fully isolated headers that take up too much space would look to Mega-Fit Connectors as a solution. Available in single-row wire-to-board or dual-row wire-to-wire and wire-to-board configuration, Mega-Fit’s compact design offers engineers space-savings with fully protected header terminals all housed in a small package. Mega-Fit delivers up to 30.0 A of current per circuit and is available with new housing material that meets V0 and glow-wire European standards, new latch design that provides superior retention when mated to the header with low-mating force, and new locking latch with grip steps for superior mating retention. Mega-Fit’s internal receptacle locking mechanism supports tangless locking terminal with low insertion force.
Series 245136 Overmolded Mega-Fit-to-Mega-Fit Cable Assemblies
Conclusion
Molex connectors are a major force in power delivery and distribution on a global scale, offering a vast array of wire-to-wire, wire-to-board and board-to-board configurations. Billions of Fit Family Power Connectors have shipped worldwide. Molex is still breaking new ground by packing even more power into less space and making connectors easier to assemble and secure. Our engineers work round the clock to design and manufacture Fit Power Connectors that not only increase our customers’ assembly efficiency but add value to the very systems that use them. As for Molex, the brand is not just about what we do, but rather, how we do it. It’s what sets us apart as we elevate the Power of our connections to improve our world. We’re Creating Connections for Life.