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

MDD series: Dual density modular connector

The MDD series has a similar structure to MHD, but focuses more on a dual density layout, which means achieving a higher density of signal contacts within the same housing size. Its technical characteristics, materials, environment, and electrical parameters are basically the same as MHD, with the main differences reflected in:

3.1 Module Configuration

The MDD series provides a view of the socket mating surface, showcasing dual or even multiple rows of micro contact layouts. Typical configurations include 100 core, 200 core, etc.

3.2 Termination method

Same termination code system as MHD series:

Used for through-hole welding on 10/11/30/31/96, etc

44 grade for SMT

3.3 Guiding device

The MDD series guide component models are highly compatible with MHD, including:

Public polarization vertical installation: 111

Mother polarization vertical installation: 121122

Mother non polarized vertical installation: 126

Mother full polarization vertical/horizontal: 130133

Power supply/high current guidance: 190 (female, vertical), 191 (male, horizontal)

3.4 Board Preparation Details

The MDD series also provides drilling layout diagrams for 100 and 200 cores, emphasizing the correspondence between the contact positions of straight, 90 °, and SMT end connections and the PCB aperture.

MDP series: dedicated high-density connectors

The MDP series is positioned as a dedicated high-density connector, suitable for applications that require extremely high contact density and have strict space constraints. Its technical characteristics are consistent with MHD/MDD, but emphasize more on:

4.1 Simplified ordering code

The MDP series only offers a 200 core configuration, with MDP as the coding series and a fixed layout of 200. The component polarity only supports 1.9 (male, MIL tin plated) and 2.8 (female, MIL tin plated), and the termination methods include 10/31/44/96. The guiding methods include 114 (male non polarized vertical), 125 (male non polarized horizontal), 122 (female polarized vertical), and 134 (female polarized horizontal).

4.2 Dimensions and Guidance

The MDP series provides external dimension drawings of plugs and sockets, clearly indicating:

The socket end can be paired with a male non polarized guide (such as 125)

The plug end can be paired with a female polarization guide (such as 122)

Surface mount end connections adopt non aligned PCB design (reference number 44)

4.3 Board preparation details

The catalog provides a complete drilling layout diagram of 200 core MDP, including the position matrix of the contact pieces under the straight end connection and surface mount end connection.

Product Line Overview and Application Suggestions

Smiths Connectors has built a complete product matrix covering standard high-density, ultimate dual density, and dedicated high-density applications through three major series: MHD, MDD, and MDP. All series are based on Hyperbolic hyperboloid contact technology, ensuring long-term reliability under high insertion and extraction times, strong vibration impact, wide temperature range, and strict electrical requirements.

5.1 Selection Suggestions

MHD series: Suitable for complex systems that require mixed configuration of signals, power supplies, coaxial or high-frequency contacts, such as military aviation electronic equipment, radar systems, and base station backboards.

MDD series: suitable for pure signal or low-power applications with extremely high PCB area requirements, such as portable testing equipment and high-density acquisition cards.

MDP series: suitable for standardized 200 core high-density interconnects, such as aerospace computer modules and internal stacking of medical imaging systems.

5.2 Design Considerations

When preparing the board, it is necessary to refer to the drilling layout diagram corresponding to the number of contacts, especially when mixing configurations, it is necessary to contact the technical department for accurate layout.

The selection of guide components should consider the insertion and removal direction (vertical/horizontal), polarization requirements, and whether a dedicated guide for power/high-frequency contacts is needed.

For applications that require more than 5000 insertions and removals, Hyperboloid technology can still support higher numbers, but it is recommended to consult the original factory life curve.

When assembling high-frequency contacts, attention should be paid to the length of cable stripping and the matching of crimping tools.

5.3 Other Smiths Connectors product lines

In addition to MHD/MDD/MDP, Smiths Connectors also offers:

Modular/rectangular connector: supports mixed signal, power, coaxial, fiber optic, and pneumatic modules.

Circular connector: M12/M23/M40/M58, metal/plastic casing, push-pull locking.

Spring probe connector: Z-axis compliant, high lifespan, suitable for board testing and blind insertion.

Fiber optic connector: ARINC 801 standard, extended beam and floating fiber optic terminal.

Filter connector: EMI/RFI filter, transient protection, RoHS compatible.