DIN 41612: Not Just for Telecom Anymore
Available for decades, DIN 41612 connectors are well known to almost every design engineer. DIN was originally developed as a backplane interconnect solution for the telecom market, where it became an industry standard. Today, a considerable portion of DIN connectors are still consumed by telecom, but they are rarely designed into new platforms; yet DIN remains an important part of the connector world, and new products and extensions are introduced on a regular basis.
DIN’s decline in the telecom market has everything to do with speed. DIN’s maximum data rate of 622 Mb/s no longer supports the requirements of the newest telecom platforms, where speeds are measured in Gb/s, and the DIN utilized in that market tend to be in support of legacy platforms. Ongoing innovation in DIN is being driven by a number of other markets, where it continues to be an important interconnect building block, including industrial automation, medical, military, aviation/aerospace, and test and measurement.
DIN’s proliferation beyond the telecom world can be attributed to a few factors, most important of which is its adoption as part of the VMEBus standard, also known as Eurocard. Over time, this architecture has found broad acceptance in several markets and applications well beyond computing, where it began. Eurocard’s continued popularity is somewhat of a testament to how well thought out and versatile the building practice is. As DIN’s popularity grew with that of VMEBus, the design community embraced it as a solid interconnect in its own right, providing sufficient density and data transmission capability for most applications. Because of this, DIN 41612 usage hasn’t been restricted to platforms incorporating VMEBus. In these newer markets, DIN is just as likely to be found in a non-VMEBus platform as it is in one that uses the packaging standard.
Trends in DIN 41612 tend to mirror those of the electronics industry as a whole. First there is density, to offer more functionality in a smaller package. While the basic interface of DIN is dictated by the standard, connector manufacturers have worked around this to develop other solutions to optimize space. For example, HARTING recently introduced its Type 3C female cable connector housing, a compact unit designed for use with very small printed circuit boards or assemblies to provide more I/O capability in the same amount of panel space. Some suppliers have also improved packaging density by incorporating additional functionality into the connectors themselves, going beyond standard signal and power to offer optional RF coax contacts or fiber optic interfaces built into the connectors.
The need for lower-cost solutions is a growing trend as well, and suppliers attempt to satisfy customer requirements in a number of ways. First, they redesign their products to optimize manufacturing cost. As DIN has been in production for quite some time, it is common that some tooling has reached the end of its useful service. Since new molds, dies, and assembly equipment must be produced anyway, it creates an opportunity for improvements in component design as well as the manufacturing process. Decreasing the machine time required to build a component, whether it be in stamping, molding, or assembly, results in lower manufacturing costs that can be passed along to customers.
In the telecom world, most DIN is used for connecting daughtercards to backplanes. The new markets in which DIN has found acceptance, however, require much more versatility and functionality from an interconnect. For example, industrial automation topography tends to be less centralized, utilizing multiple devices and requiring higher levels of I/O capability, as well as other packaging challenges. Connector manufacturers have responded by developing DIN product extensions and solutions to meet such challenges. Regardless of what connection might be required, someone has likely tooled it up in DIN 41612.
A quick survey of manufacturers’ offerings shows availability of products for configurations such as mezzanine and extender cards, as well as options for cable termination, in addition to traditional backplane-to-daughtercard right-angle configurations. DIN can be found with pin counts as low as three and as high as 160. Some configurations are also available in reverse gender and most are offered in various board terminations types (press-fit, solder, crimp, etc.). With such a range of choices in DIN, design engineers can more or less standardize on one connector type, lowering the number of unique part numbers across their platforms. Reduced supply chain complexity means lower cost.
Another area being addressed by manufacturers in terms of cost reduction is board processing. DIN is now available from several connector suppliers configured for thru-hole reflow termination (also known as pin-in-paste). This technology allows larger components, such as DIN connectors, to be processed along with traditional surface-mount components. Connectors are applied to the printed circuit board by a pick-and-place machine, then passed through a reflow oven. This provides significant cost savings in programs that require separate wave solder or press-fit operations for terminating connectors to the PCB by eliminating this extra manufacturing step.
Safety and Robustness
Many of the current applications for DIN require a level of safety and security beyond what was originally envisioned for the product. For example, a cable plugged into the wrong port or backing out of a port on an aircraft flight control system could have grave consequences. Manufacturers offer improvements through various families of accessories, including devices for retention, such as thumb screws and metal latches, as well as those meant to prevent plugging into the wrong connection, such as coding keys.
While DIN 41612 may be one of the older connector designs in existence, it continues to be widely used in the electronics industry. Ongoing innovation for the product is driven not by telecom, but by several other markets. These are markets with a broad spectrum of interconnect requirements that connector manufacturers are readily supporting, making DIN 41612 a highly functional and cost-effective solution that will remain a key component for the foreseeable future.
By Sean Riley, Consultant