Revolutionary MEMS switch handles 200V, 10A

March 19, 2018 // By Julien Happich
Californian startup Menlo Micro is commercializing a 200V/10A Digital-Micro-Switch (DMS) MEMS-based smart power relay that it says can revolutionize the power industry.

Until now, says the GE spinout, many industries have had to live with the tradeoffs of solid-state controls, including high-leakage currents, lack of air gap and complicated thermal management, or electromechanical solutions that are slow, bulky and expensive. 

For its 200V/10A DMS smart power relay, Menlo has combined over 200 micromechanical high-voltage switches, with fully integrated protection and controls, and designed it into a Smart Power Relay evaluation board. The credit-card-sized board is capable of carrying 10A of DC current, without the need of a heat sink.

Typically, these switches are 3-terminal devices operating in the 25W to 50W range. For the Smart Power Relay, Menlo has created a fully isolated 4-terminal architecture, complete with advanced features such as over-current protection. 

In an interview with eeNews Europe, Menlo Micro's Senior Vice President of Products Chris Giovanniello gave us a glimpse of the future.

As the company is using the same proprietary materials and processes across all its lines of switches (RF and power), it can make different products with exactly the same mask, only using a different number of switches (through step replication), explained Giovanniello. Describing the MEMS switches as mechanical transistors, he said those could be used as elementary blocks to design power switches.

"For the power relay, we simply stack more of those mechanical transistors, which allows us to push 10A through it" Giovanniello said. "The more metal, the more contacts, it can scale nicely to massive arrays" he said, adding that power relays could easily be built to handle 20, 50, 80 or even over 100 Amps.

The DMS Power Relay architecture boasts an 80 to 90 percent reduction in volume and weight over electromechanical relays. Each metal-to-metal contact is smaller than a human hair, and when combined in massive arrays, can provide extremely low on-state losses (<10mohm) in a very small package, eliminating the need for large, heavy heat sinks. This will enable entirely new form factors for power electronics designers.

The new relays offer a 1000x improvement in switching speed over traditional electromechanical relays and can be integrated into traditional semiconductor packages (like System-in-Package or Multi-Chip-Modules) while retaining the galvanic isolation properties of traditional mechanical relays.