Smiths Connectors MHD/MDD/MDP CONNECTOR SERIES PCB High Density Connectors

Smiths Connectors MHD/MDD/MDP series high-density PCB connectors

In modern electronic systems, with the continuous improvement of functional integration, the demand for signal and power interconnection on PCBs (printed circuit boards) is becoming increasingly complex. High density, high reliability, and miniaturization have become the core challenges in connector design. Smiths Connectors, with its innovative Hyperbolic contact technology, has launched three series of high-density PCB connectors: MHD, MDD, and MDP, which are widely used in fields such as aerospace, military, industrial control, communication equipment, and medical electronics that require high reliability. This article is based on the original content of the official product catalog "MHD Catalog - (A4)", systematically organizing and deeply analyzing the technical characteristics, structural configuration, material selection, electrical performance, and application advantages of these three connectors, providing authoritative and professional technical references for engineering designers.

Hyperbolic Contact Technology: Core Advantages

The core technology foundation of the MHD, MDD, and MDP series is Smiths Connectors' proprietary Hypertec (Hyperbolic Contact) hyperboloid contact technology. This technology arranges the metal wires inside the contact sleeve in a hyperbolic trajectory to form an elastic wire contact structure around the pin. Compared with traditional leaf springs or point contact methods, the Hyperboloid structure has the following significant advantages:

1. Low insertion and extraction force

By precisely controlling the angle between the pin and the metal wire inside the sleeve, extremely low insertion and extraction resistance can be achieved. The metal wire is smoothly deflected during pin insertion, forming a linear contact that ensures contact pressure and reduces insertion and removal forces.

2. Ultra long contact life

The wiping action of the Hyperboloid structure is extremely gentle, greatly reducing mechanical wear on the contact surface. This series of connectors can support up to 100000 insertion and extraction cycles with almost no performance degradation, significantly better than traditional connectors.

3. Extremely low contact resistance

Due to the formation of multiple linear contact paths between the metal wire and the pin, the actual contact area is much larger than that of point or line contact designs. At the same time, the wiping action can continuously remove surface oxide layers or pollutants, keeping the contact interface clean. The measured signal contact resistance is ≤ 12 m Ω, and the power contact resistance is ≤ 2 m Ω, which is about half of the traditional design.

4. Higher current carrying capacity

The Hyperbolic structure can optimize current carrying capacity by adjusting the number, diameter, and angle of metal wires. The contact area is distributed on a larger surface, allowing the current carried by the unit metal wire to be safely doubled. The rated current of the signal contact is 3A, and the power contact can reach 15A.

5. Impact and vibration resistance performance

The metal wire is lightweight and has low inertia, and can follow the displacement of the pin in real-time in impact or vibration environments, maintaining continuous contact. The contact area is evenly distributed 360 ° around the pin, and the three-dimensional symmetrical structure ensures uninterrupted electrical connection under any directional disturbance.

6. Applicability of high-density interconnect systems

Due to the lack of additional hardware to overcome insertion and extraction forces, the MHD/MDD/MDP series can significantly reduce the size and weight of subsystem designs, making it particularly suitable for high-density inter board interconnect applications.

MHD series: high-density modular connectors

2.1 Overview of Technical Characteristics

The MHD series is a flagship product for high-density PCB applications, supporting mixed configurations of signal, power, coaxial, and high-frequency contacts.

Materials and Coatings

Insulator: Diallyl phthalate (DAP), flame retardant grade UL94 V-0

Frame: Aluminum alloy

Contact: Copper alloy

Guiding element: brass+nickel or stainless steel

Contact coating: nickel base+gold surface

environmental performance

Working temperature range: -55 ° C to+125 ° C

Contact anti exit safety distance: static 2.0 mm, dynamic 1.80 mm

Standard insertion and extraction times: 5000 times

Pull out force of single contact: ≤ 0.5 N

Special contact: Compliant with NFC 93569 standard

Electrical performance

Contact resistance: signal ≤ 12 m Ω, power supply ≤ 2 m Ω

Rated current: signal 3A, power supply 15A

Insulation resistance:>10 ⁴ M Ω

Rated voltage: 200V

Voltage resistance: 800V

Signal contact diameter: 0.50 mm

Diameter of power contact: 2.00 mm

Coaxial impedance: 50 Ω

2.2 Ordering Code Rules

The MHD series adopts a five bit encoding structure:

Series: MHD

Layout: such as 052, 5HA, 100, 1HB, 200, etc

Components - Polarity - Coating:

1.5: Male plug, MIL coating

2.4: Female socket, MIL coating

1.9: Male plug, MIL tin plated

2.8: Female socket, MIL tin plated