Q&A with Russ Garcia: The Reinvented Electromechanical Switch and Bringing New Tech to Market

Russ Garcia (CEO, Menlo Microsystems) has 30 years of experience in the electronic systems and semiconductor industries. He recently told us about Irvine, CA-based Menlo Micro’s innovative Digital-Micro-Switch (DMS) platform and shared his thoughts on how the company’s solution can improve a wide variety of technologies ranging from communications networks to electric vehicles.

C. J. Abate: Menlo Microsystems launched in 2016 as a spin-out from General Electric. What is Digital-Micro-Switch technology?
 
Russ Garcia: Menlo Micro’s Digital-Micro-Switch platform is the reinvention of the most basic electronic function, the switch. It is a game changer for those who design electronic systems with a market opportunity of more than $20 billion. It has the potential to serve multiple industries, including: next-generation 5G mobile networks, industrial IoT markets, battery management, energy management, enterprise building management, home automation, electric vehicles, and medical instrumentation.
 
The electromechanical switch hasn’t experienced much change in the past 150 years, and many of the applications we are revolutionizing have seen little innovation in the last 25 years. Menlo Micro’s innovations have come to market by developing unique materials, designs and processing techniques to build an enhanced electronic switch that can handle high-temperature, high-stress conditions for products that require decades of useful life. The new switch operates up to 1000× faster than a typical mechanical switch with 1000× longer lifetime. It can handle hundreds of watts of power and is built in a structure smaller than a human hair. 
 
C. J.: How do Menlo devices compare to traditional electromechanical relays? What are the advantages of the Digital-Micro-Switch platform?
 
Russ: Driven by the extreme operating conditions required by General Electric's industrial businesses, the GE Global Research team was led to look at the micro-mechanical switch from an entirely different perspective. That different approach led to a deep understanding of failure modes, and in turn, the development of a unique set of patented metal alloys and processing techniques that enable reliable operation and extremely good electrical performance — primarily resulting in very low contact resistance.

With the core technology development completed and qualified for production in GE systems, the Menlo Micro team is bringing high-performance switch products to multiple end markets, with a goal of revolutionizing the way electronic systems are designed. Some of the key attributes of the Menlo Micro switch technology include size, speed, power handling, power efficiency, and reliability.

Size: Board space and weight are at a premium in many applications. Traditional mechanical switches take up lots of space, have limited number of channels, and in some cases need to be manually assembled. Menlo Micro switching elements are smaller than the width of a human hair and are architected to be scalable, depending on the power ratings required. All switches are manufactured using automated wafer-level processes and tools. They are so small we can fit hundreds of them in a space smaller than 10 mm².

Speed: Making mechanical structures small also means you can make them move fast. A typical mechanical switch might operate in a few milliseconds, whereas Menlo Micro switches can operate 1000× faster, in only a few microseconds. This can have enormous implications on systems that were previously limited in performance by how fast they could reconfigure, or open and close critical circuits.

Power Handling: This is an area where Menlo Micro completely throws conventional wisdom out the window. When faced with the prospect of handling higher power levels, most people think bigger. More mass, more metal, larger air gaps between conductors. We took a different approach. We make everything smaller and move the electrical contacts closer and closer together. Our miniaturized switches and scalable architecture allows us to handle hundreds of volts and tens of amps without arcing. 

Power Efficiency: In an increasing number of systems, power is getting more and more expensive. When you're working off a battery, every 0.1 dB and every microamp counts. Both RF and AC/DC losses need to be balanced with amplification and in some cases with extra power supplies. This is where the Menlo Micro technology really shines. We can scale our switches to have ultra-low losses, from 1 Ω down to a few milliohms. And not only that, but our electrostatic-driven actuator means that a single switch only needs a few picoamperes (pA) to function.  

Reliability:  When you are developing products to meet the needs of businesses that serve markets like healthcare, aviation, and other mission-critical industrial applications, reliability is not an afterthought; it's the primary design criteria. In the end, that's why we are here. Our mechanical switching device has lifetimes more than 1000× longer than traditional mechanical switches; not millions of cycles, but tens of billions of cycles without degrading performance. Even more important than the performance demonstrated to date, is the deep understanding in material science, reliability, and failure analysis that enables us to model and predict failures so we can push the technology even further.
 
C. J.: Tell us a bit about each of the products in your portfolio: HV switch products, RF switching products, RF tuning products, and power relay products.
 

Russ: The MM7100 is a high-voltage SPST switch (Figure 1). The MM7100 was the first Menlo Microsystems product in production. It has been shipping into GE’s MRI applications and over 100,000 of these switches have been shipped to date.

The MM7100 provides ultra-low on-state resistance and high off-state isolation, with greater than 3 billion switching cycles guaranteed at +85°C. Because of its long lifetime, extremely low current consumption, and small form factor, the MM7100 is an ideal solution for replacing electromechanical relays, as well as pin diode switches where size, weight, power, and thermal management are critical system-level design parameters.
 

The MM5120 is a high-power RF/microwave switch. Our DMS technology enables 25 W or more of RF power switching in a very small SMT package (Figure 2). The MM5120 provides ultra-low insertion loss and superior linearity from 12 GHz down to DC, with greater than 3 billion switching cycles guaranteed at elevated +85°C temperatures. An integrated analog gate controller allows the user the option to provide the required high-voltage gate signal externally or to generate it internally. The MM5120 is an ideal solution for replacing bulky and less reliable RF electromechanical relays, as well as RF/microwave solid-state switches where linearity and insertion loss are critical parameters.
 

The MM3100 device is a high power six-channel SPST for DC and wideband RF/microwave switch applications (Figure 3). The MM3100 is capable of switching greater than 25 W of RF power. It has six switch channels — each providing ultra-low on-state insertion loss and high off-state isolation from DC to 3 GHz with greater than 3 billion switching cycles at elevated +85°C temperatures. Each channel is individually controlled by a standard Serial Peripheral Interface (SPI) synchronous bus. An external +5 VDC logic supply and high voltage +77 VDC bias source is required for operation of the internal switch driver. 
 
The MM1200 device is a six-channel SPST Micro Relay. It is intended for power and signal switching applications in both DC and AC circuits. This device has very low on-state contact resistance, is capable of up to 1.0 A of current handling per channel and high off-state isolation with greater than 3 billion switching cycles at elevated +85°C temperatures. Each switch is normally open (NO) and individually controlled by a serial peripheral interface (SPI) bus. An external +5 VDC logic supply and high voltage +77 VDC bias source is required for operation of the internal switch driver.
 
C. J.: How are your switches currently being used?
 
Russ: Our Digital-Micro-Switch products are highly versatile and can be used in different configurations for multiple applications. Initially, our MM7100 and MM3100 products are being used to replace high-voltage PIN diodes in end products such as MRI machines and military radios. Our MM1200 is being used to replace reed relays electromechanical relays in test and measurement equipment. In almost all cases, our customers are trying to reduce the overall size, weight, and power consumption of the system they are designing, so the extremely low power and ultra-small form factors that we are providing with the DMS technology are very attractive in those situations. These devices scale like semiconductor devices but have electrical performance characteristics of high-performance ohmic contact switches. Subsequently, they address high-power, high-frequency, high-reliability applications, while also scaling to enable high-frequency performance at lower powers for more cost-sensitive applications.
 
C. J.: What’s your business model? Do you license your technology?
 
Russ: We primarily design and manufacture both standard and custom switches and relays for numerous vertical markets and applications. We do have a licensing model for various fields of use for which we do not intend to participate with products directly. One example of that is the consumer mobile handset market where the DMS technology enables millimeter Wave performance at cost structures rivaling SoI switch technology that is used in those applications today.
 

C. J.: What are the technical specifications for the Smart Power Relay evaluation board?
 
Russ: Menlo Microsystems has developed a Power Relay Prototype Platform that uses digital micro switches in a scalable, parallel configuration to handle larger currents. The positive temperature coefficient of the DMS technology enables paralleling devices with stable current sharing between devices (Figure 4).
 
The rest of this interview will appear in Elektor Business Edition issue 4/2018, which will be published in July 2018.