Category Archives: Newsworthy

RF MEMS Switches for 5G Networks

For high-power RF designs like 5G networks, Menlo Micro has added an RF MEMS switch that contains an integrated driver circuit for a charge pump. The RF MEMS switch operates from DC to 6 GHz.

The new RF switch from Menlo Micro is one of a family of SP4T or single-pole/four-throw, DC-t0-6 GHz switch, and is meant for 5G infrastructure, measurement, and testing equipment involving high-power RF switching applications. Menlo Micro is using its own Ideal Switch technology for the high integration MM5140 SP4T switch. The technology gives the new switch power handling capability up to 25 W, an ultra-low insertion loss, and the highest linearity in the industry. The MM5140 SP4T switch easily outperforms all types of traditional solid-state switches and electromechanical relays.

The MM5140 SP4T switch performs RF operations at high power levels over a wide temperature range of -40 °C to +85 °C, delivering superb linearity from DC to 6 GHz. 5G RF applications demand significant reductions in distortion, which the switch’s IP3 of 95 dBm provides conveniently.

Menlo Micro has custom designed a built-in high-voltage charge pump or driver circuit and integrated it into the LGA package of the MM5140 SP4T switch. The charge pump circuit has both GPIO and SPI digital interfaces so that any test system or host processor can keep control over it.

Although the new module has the existing MM5130 at heart, it also has the CMOS charge pump driver ASIC, driver circuitry, and other peripheral passive components in its 5.2 X 4.2 mm package.

As the MM5140 SP4T switch is a single-pole four-throw device, the voltage must route over to each of the four gate lines. This requires the presence of either a MOSFET drive circuit or a dedicated multiplexer IC. Along with the integrated charge pump and the driver circuitry, the MM5140 SP4T switch saves board area and bill of materials.

The integrated passive components include a large capacitor that the charge pump requires for handling the high voltage that drives the MEMS. This helps reduce the BOM for passive components.

The difference between the MM5130 and the MM5140 is their operational speed. The MM5130 is a design meant to operate at higher frequencies, such as the microwave band. The design of the MM5140 is meant for a sub-6 GHz application. The MM5140 comes in an LGA package rather than the WLCSP of MM5130. That makes it easier for customers to design their boards, as the LGA package has a bigger pitch.

Moreover, Menlo Micro has eliminated some external components for the MM5140 design reduces its complexity. This helps in simplifying RF front-end development including receivers and transmitters, beamforming antennas, and RF filters. These are necessary for radar systems and advanced radio architectures.

5G base stations typically use RF/microwave solid-state switches and RF electromagnetic relays that the MM5140 SP4T switch can replace. The replacement offers significant improvements over the competing technologies, especially in the integrated capability, BOM count reduction, and real-estate savings on the board. Moreover, the MM5140 SP4T switch exhibits far better reliability over the other competing technologies.

Wi-Fi 5.0 to Wi-Fi 7.0

Both on smartphones and in living rooms, the audio & video streaming revolution is producing an insatiable demand for speed and bandwidth. To satisfy this demand, in the early 2010s, we had the Wi-Fi 5. However, this lasted only for a decade or so, because by then, consumers had bidirectional video applications such as Webex, WhatsApp, and other social media uploads like TikTok. These had begun to alter not only the consumer landscape but also that of the enterprise.

That led to the catapulting of Wi-Fi 6 to the arena for better management of the huge traffic of streamlining wireless transmissions. This was followed by Wi-Fi 6E which literally extended the benefits of its predecessor with the availability of the 6 GHz band. The pandemic of Covid-19 in 2020 was the moment for Wi-Fi 6 and Wi-Fi 6E, as is evident from the 1+ billion chips of Wi-Fi 6 and Wi-Fi 6E that Broadcom shipped in the past three years.

And still, the demand for higher bandwidth and speed continues only to increase. A recent study has shown that consumer spending on games has increased by 40%. This involves not only devices operating at higher speed, but also the use of newer technology like AR or augmented reality and VR or virtual reaility headsets as new gaming devices. While these devices demand unprecedented levels of immersion while playing, they also call for deterministic and reliable wireless data.

So, we are now moving towards Wi-Fi 7. It has the ability to incorporate 320-MHz channels into the 6 GHz band and employ the 4096-QAM modulation technique, thereby effectively doubling the channel bandwidth. Additionally, it employs better technologies for lowering latency and bolstering determinism. These include AFC or automatic frequency coordination and MLO or multi-link operation.

Wi-Fi 7 comes with spectrum flexibility spanning three bands. However, the critical role is played by the incorporation of 320 MHz channels into the 6GHz band for doubling the speed. For boosting the coverage and the overall network performance, there is the 4096-QAM technique that plays a crucial role.

Wi-Fi 7 can rapidly aggregate channels in congested, high-density networks. This is due to its MLO or multi-link operation that significantly improves its deterministic performance. By rapidly switching traffic among several channels, Wi-Fi 7 can drive greater capacity, thereby facilitating commercial-grade QoS or quality of service in its networks.

Another technology that Wi-Fi 7 utilizes is AFC or automatic frequency coordination. This technique allocates optimum spectrum, thereby enabling high-power access points and extending the 6 GHz range outdoors and indoors. According to Broadcom, its Wi-Fi 7 designs with AFC are capable of 63 times greater transmitting power. This helps not only to extend the range but also the coverage of the 6 GHz band in use.

Therefore, with its immense focus on speed, latency, and determinism, Wi-Fi 7 has entered our lives and is here to stay. According to the forecast of industry technology analysts, revenue from Wi-Fi 7 will supersede that from any other Wi-Fi technology so far in the next five years.

What are Stacked 3D ICs?

Just like any big city, electronics is evolving with great rapidity, such that both are running out of open space. The net result is a growth in the vertical direction. For a city, vertical growth promises more apartments, office space, and people per square mile. For electronics, there is the slowing of Moore’s law and the adoption of new advanced technology. That means chip developers cannot increase density and speed from shrinking processes and smaller transistors. Although they can increase the die capacity, this suffers from longer signal delays that reduce yield. That limits the expansion in X-Y directions, which means the only option remaining is building upwards.

Among the many established forms of vertical integration, there are 2.5D ICs, flip-chip technology, inter-die connectivity with wire bonding, and stacked packages. However, all these suffer from constraints that limit their value. Three-dimensional integrated circuits or 3-D ICs offer the highest density and speed.

Three-dimensional ICs are monolithic 3-D SoCs built on multiple active silicon layers. These layers use vertical interconnections between the different layers. So far, this is an emerging technology and has not been widely deployed. Furthermore, there are stacked 3-D ICs with multiple dies that manufacturers have stacked, aligned, and bonded into a single package. They use TSVs or through silicon vias, and a hybrid bonding technique to complete the inter-die communication. Stacked 3-D ICs are now commercially available, offering an option for larger dies or migration to leading-edge nodes that are very expensive.

Stacked 3-D ICs offer an ideal option for applications requiring more transistors in a given footprint. For instance, a mobile SoC requires high transistor densities but has limits on its footprint and height. Another example is cache memory chips. Manufacturers usually stack them on top of or below the processor to increase their bandwidth. This makes stacked 3-D ICs a natural choice for applications that are on the limits of a single die.

Vertical stacking offers a smaller footprint with faster interconnections compared to multiple packaged chips. Rather than a single large die, splitting it into several smaller dies provides a better yield. For the manufacturer, there is flexibility in stacking heterogeneous dies, as they can intermix various manufacturing processes and nodes. Moreover, it is possible to reuse existing chips without redesigning them or incorporating them into a single die. This offers a substantial reduction in risk and cost.

Although there are numerous benefits and opportunities from the use of stacked 3-D ICs, they also introduce new challenges. The architecture of 3-D silicone systems needs a more holistic approach, taking into account the third dimension. It is not sufficient to think of 3-D ICs only in terms of 2-D chips stacked on top of each other. Although it is necessary to optimize power, performance, and area in the familiar three-way approach,  the optimization must be in every cubic millimeter rather than in every square millimeter. All tradeoff decisions must take into account the vertical dimension also. This requires making the tradeoffs across all design stages, including IP, architecture, chip packaging, implementation, and system analysis.

The Battery of the Future — Sodium Ion

Currently, Lithium-ion batteries rule the roost. However, there are several disadvantages to this technology. The first is that Lithium is not an abundant material. Compared to this, Sodium is one of the most abundantly available materials on the earth, therefore it is cheap. That makes it the most prime promising candidate for new battery technology. So far, however, the limited performance of Sodium-ion batteries has not allowed them a large-scale integration into the industry.

PNNL, or the Pacific Northwest National Laboratory, of the Department of Energy, is about to turn the tides in favor of Sodium-ion technology. They are in the process of developing a Sodium-ion battery that has excelled in laboratory tests for extended longevity. By ingeniously changing the ingredients of the liquid core of the battery, they have been able to overcome the performance issues that have plagued this technology so far. They have described their findings in the journal Nature Energy, and it is a promising recipe for a battery type that may one day replace Lithium-ion.

According to the lead author of the team at PNNL, they have shown in principle that Sodium-ion battery technology can be long-lasting and environmentally friendly. And all this is due to the use of the right salt for the electrolyte.

Batteries require an electrolyte that helps in keeping the energy flowing. By dissolving salts in a solvent, the electrolyte forms charged ions that flow between the two electrodes. As time passes, the charged ions and electrochemical reactions helping to keep the energy flowing get slower, and the battery is unable to recharge anymore. In the present Sodium-ion battery technologies, this process was happening much faster than in Lithium-ion batteries of similar construction.

A battery loses its ability to charge itself through repeated cycles of charging and discharging. The new battery technology developed by PNNL can hold its ability to be charged far longer than the present Sodium-ion batteries can.

The team at PNNL approached the problem by first removing the liquid solution and the salt solution in it and replacing it with a new electrolyte recipe. Laboratory tests proved the design to be durable, being able to hold up to 90 percent of its cell capacity even after 300 cycles of charges and discharges. This is significantly higher than the present chemistry of Sodium-ion batteries available today.

The present chemistry of the Sodium-ion batteries causes the dissolution of the protective film on the anode or the negative electrode over time. The film allows Sodium ions to pass through while preserving the life of the battery, and therefore, quite significantly critical. The PNNL technology protects this film by stabilizing it. Additionally, the new electrolyte places an ultra-thin protective layer on the cathode or positive electrode, thereby helping to further contribute to the stability of the entire unit.

The new electrolyte that PNNL has developed for the Sodium-ion batteries is a natural fire-extinguishing solution. It also remains non-changing with temperature excursions, making the battery operable at high temperatures. The key to this feature is the ultra-thin protection layer the electrolyte forms on the anode. Once formed, the thin layer remains a durable cover, allowing the long cycle life of the battery.

SD-Card Level Translator with Smaller Footprint

Interfacing SD-Cards with their host computers almost always requires a voltage-level translator. This is because most of these memory cards operate at signal levels between 1.7 and 3.6 VDC, while their hosts operate with nominal supply levels varying from 1.1 to 1.95 VDC. Until now, bidirectional level translators for SD 3.0 memory cards were WLCSP devices with 20 bumps or solder balls. The new translator for SD 3.0 memory cards, from Nexperia, is a WLCSP device with 16 bumps. Its footprint is 40% smaller than the 20-bump types. The new device, NXS0506UP, supports multiple data and clock transfer rates for signaling levels that the SD 3.0 standard specifies. Moreover, this includes the SDR104 mode for ultra-high speeds.

While shifting the voltage levels between the memory card and the I/O lines of the host device, the new translator operates at clock frequencies of up to 208 MHz and handles data rates up to 104 Mbps. To automatically detect whether data and control signals should move from the host to the memory card (card write mode) or from the memory card to the host (card read mode), the device uses its integrated auto-directional control.

Apart from the auto-directional control, Nexperia has substantially reduced the BOM cost of their NXS0506UP device by integrating the pull-up and pull-down resistors. These resistors are essential in establishing the voltage levels at the chip IO lines, and discrete resistors push up the BOM cost. In addition, the input/output driver stages of the device have inbuilt EMI filters that help to reduce interference. Moreover, Nexperia has provided robust ESD protection, according to the IEC 61000-4-2 standard, on all the side pins of the memory card. While the 16-bump WLCSP has a physical measurement of just 1.45 x 1.45 x 0.45 mm, its operating temperature ranges from -40 °C to +85 °C.

The NXS0506UP SD card voltage level translator is useful for consumer devices like automotive systems, medical devices, notebook PCs, digital cameras, and smartphones. The SD 3.0 standard compatible level translator is a bidirectional dual supply device with auto-direction control. Nexperia has designed the card for interfacing cards operating from 1.7 to 3.6 VDC levels to hosts with a nominal supply voltage between 1.1 to 1.95 VDC. Apart from the SD 3.0 standard, the device also supports the SDR12, SDR25, DDR50, SDR50, SDR104, and the SD 2.0 standards at default speeds of 25 MHz and high speeds of 50 MHz. The device offers built-in protection from ESD and EMI conforming to the IEC 61000-4-2, level 4 standard.

There are several benefits to using the NXS0506UP SD card voltage level translator. The primary benefit is it supports a maximum clock rate of 208 MHz. It translates voltage levels for default and high-speed modes. It has auto-direction sensing for data and controls. The power consumption is low, while the device integrates pull-up and pull-down resistors. The integrated EMI filter suppresses higher harmonics at digital IOs. Buffers at the IO lines help to keep ESD stresses away with the zero-clamping concept. The 16-bump WLCSP package offers a pitch of 0.35 mm.

Advantages of Additive Manufacturing

Additive manufacturing, like those from 3-D printers, allows businesses to develop functional prototypes quickly and cost-effectively. They may require these products for testing or for running a limited production line, allowing quick modifications when necessary. This is possible because these printers allow effortless electronic transport of computer models and designs. There are many benefits of additive manufacturing.

Designs most often require modifications and redesign. With additive manufacturing, designers have the freedom to design and innovate. They can test their designs quickly. This is one of the most important aspects of making innovative designs. Designers can follow the creative freedom in the production process without thinking about time and or cost penalties. This offers substantial benefits over the traditional methods of manufacturing and machining. For instance, over 60% of designs undergoing tooling and machining also undergo modifications while in production. This quickly builds up an increase in cost and delays. With additive manufacturing, the movement away from static design gives engineers the ability to try multiple versions or iterations simultaneously while accruing minimal additional costs.

The freedom to design and innovate on the fly without incurring penalties offers designers significant rewards like better quality products, compressed production schedules, more product designs, and more products, all leading to greater revenue generation. Regular traditional methods of manufacturing and production are subtractive processes that remove unwanted material to achieve the final design. On the other hand, additive manufacturing can build the same part by adding only the required material.

One of the greatest benefits of additive manufacturing is streamlining the traditional methods of manufacturing and production. Compressing the traditional methods also means a significant reduction in environmental footprints. Taking into account the mining process for steel and its retooling process during traditional manufacturing, it is obvious that additive manufacturing is a sustainable alternative.

Traditional manufacturing requires tremendous amounts of energy, while additive manufacturing requires only a relatively small amount. Additionally, waste products from traditional manufacturing require subsequent disposal. Additive manufacturing produces very little waste, as the process uses only the needed materials. An additional advantage of additive manufacturing is it can produce lightweight components for vehicles and aircraft, which further mitigates harmful fuel emissions.

For instance, with additive manufacturing, it is possible to build solid parts with semi-hollow honeycomb interiors. Such structures offer an excellent strength-to-weight ratio, which is equivalent to or better than the original solid part. These components can be as much as 60% lighter than the original parts that traditional subtractive manufacturing methods can produce. This can have a tremendous impact on fuel consumption and the costs of the final design.

Using additive manufacturing also reduces the risk involved and increases predictability, resulting in improving the bottom line of a company. As the manufacturer can try new designs and test prototypes quickly, digital additive manufacturing modifies the earlier unpredictable methods of production and turns them into predictable ones.

Most manufacturers use additive manufacturing as a bridge between technologies. They use additive technology to quickly reach a stable design that traditional manufacturing can then take over for meeting higher volumes of production.

New Requirements for Miniature Motors

Innovations in the field of robotics are resulting in the emergence of smarter and smaller robotic designs. Sensor technologies and vision systems use robotic applications in warehousing, medical, process automation, and security fields. Disruptive technologies are creating newer opportunities for solving unique challenges with miniature motors. These include the robotic market for efficient and safe navigation through warehouses, predictable control of surgical tools, and the necessary endurance for completing lengthy security missions.

With industries transitioning to applications requiring collaborative robotics, they need systems that are more compact, dexterous, and mobile. Tasks that earlier required handling by human hands are driving the need for miniaturized motors for mimicking both the capability and size of the hands that accomplished the work.

For instance, multiple jointed solutions representing the torso, elbow, arm, wrist, etc. require small, power-dense motors for reducing the overall weight and size. Such compact solutions not only improve usability but also improves autonomy and safety, resulting in faster reaction times due to lower inertia. Therefore, robotic grippers, exoskeleton, prosthetic arms, and humanoid robots require small, high-power density motors. Power density is the amount of power a motor generates per unit of its volume. A motor that generates greater amounts of power in a small package, has a higher power density. This is an important factor when there is a space constraint, or where a high level of output is necessary when a limited space.

Manufacturers can miniaturize motors with high power densities. Alternately, they can increase the capability of current designs. Both options are critical in reducing the space that motion elements occupy. High efficiency is necessary to obtain the maximum power possible from a given design. Here, BLDC or brushless DC motors and slot-less motor designs in combination with efficient planetary gearboxes can offer powerful solutions in small packages. Brushless solutions are flexible enough for engineering them to meet customer requirements like long and skinny designs, or short, flat, low-profile configurations.

Smooth operation and dynamic response can result in these miniature motors being dexterous and agile. Slot-less BLDC motors achieve this by eliminating detent torque, thereby providing precise dynamic motion with their lower inertia. Applications requiring high dynamics, such as pick-and-place systems and delta robots, must be able to accelerate/decelerate quickly and constantly. Coreless DC motors and stepper motors with disc magnets are suitable for applications requiring critical characteristics like high acceleration as they have very low inertia.

Ironless brushed DC motors with their high efficiency, are the best choice for battery-powered mobile applications to extend their operational life between charges. Several robotic applications now run on battery power, thereby requiring motors with high efficiency for longer running times. Other applications require high torque at low speeds, and it is possible to achieve this by matching the motor with a high-efficiency gearbox.

Some applications that are inhospitable to humans may need robot systems capable of enduring difficult environmental conditions. This may include tremendous vibration and shock. With proper motor construction, it is possible to improve their reliability and durability when operating under such conditions.

Mobile Screen Over Your Eyes

It is no longer necessary to hold a mobile with the hands. How? Thanks to AR or Artificial Reality eyeglasses, it is now possible to transfer the screen of the mobile device to the lens of a pair of eyeglasses. Although this technology was around for a while, the glasses were rather cumbersome and bulky.

Now, Trilite Technologies of Vienna, Australia, has a newer approach to AR glasses that make them look and feel just like normal glasses. According to their CEO, Dr. Peter Weigand, so far, there have been three types of light engine technologies.

The first was the LCoS technology. This is a panel-based technology, and it requires optics with illumination. It is necessary to have a nice, homogeneous, and smooth illumination, and a waveguide must carry the input image. This is not a very efficient technique, and it has a number of optical elements, making it bulky.

The other was the MicroLED display technology. This is semiconductor-based and far superior to a reflective display as it emits its own light. However, it is still a challenge to make the display visible in outdoor applications. And, the two-dimensional display does not scale up when moving to higher FOV or Fields of View and higher resolutions.

The third was the Laser beam scanner technology. This has the highest level of miniaturization. Typically, it has an RGB laser module with three separately mounted lasers as the red, blue, and green light sources. Optics follows the laser module to merge the three beams of lasers into a single ray. A set of MEMS mirrors follows, generating the image scans for the eyeglass display. Two mirrors are necessary, one for the X- and the other for the Y-axis.

According to Weigand, the latest generation of these scanners uses a single MEMS mirror that can move in both x and y-direction. This two-dimensional mirror helps to achieve a lighter and smaller product.

Electronics create the image for display by modulating the lasers. Coupling the image to an optical waveguide allows it to be sent to the display. For this, the laser scanner uses relay optics, a rather large optical element. Coupling the laser beam scanner into the input coupler of the waveguide directly, allows the display engine to be made to a small size. The entire arrangement contains the collimating optics, the MEMS mirrors, and the three lasers.

Trilite Technologies is able to make very small scanners because of its design philosophy. They have designed their scanner such that software rather than hardware handles many of the scanning functions. The other significant contribution to the small size comes from using a single two-axis MEMS mirror rather than one mirror for each axis.

The waveguide contains the optical input coupler as an integral part. This coupler has a pattern of microstructure gratings on its surface, allowing light to enter. The output side, where the light emerges from the waveguide, also has a similar structure. The waveguide conveys the image to the lens and, at the same time, combines the incoming with the generated digital light, allowing the user to see both the digital image and the real-world scene through the eyeglass lens.

Optical Microphone Watches Sound

A research team from Carnegie Mellon University has claimed to have developed an optical microphone or camera system that can monitor sound vibrations very precisely. The precision is so high that the camera can capture separate audio of individual guitars playing simultaneously. That allows the camera to reconstruct the music faithfully and accurately from a single instrument even when it is playing in an orchestra or band.

Even using the most directed and high-powered microphones it is not possible to totally eliminate neighboring sounds, effects of acoustics, and ambient noise when capturing audio. The research team has used a novel approach. They used two cameras along with a laser beam. This allows them to sense the high-speed but low-amplitude vibrations from the surface of the instrument. The team uses these vibrations for reconstructing sound. The unique arrangement allows them to isolate the audio and capture it without a microphone and with no interference.

The team claims to have invented a new way of seeing sound. The camera system is innovative, represents a new device for imaging, and makes it possible to see things that are not visible ordinarily to the naked eye. The team has successfully completed several demonstrations for showcasing the effectiveness of sensing vibrations and reconstructing sound faithfully and with quality.

During their demonstrations, the team was able to successfully capture isolated audio from separate guitars that were playing together, and the audio of individual speakers that were playing assorted music at the same time. For instance, they analyzed vibrations from a tuning fork. They also captured the vibrations on a bag of burritos placed near a speaker thereby capturing the sound from the speaker.

The team significantly improves the work done earlier for capturing sound by computer vision. Where earlier researchers used high-speed cameras for producing a high-quality recording, the present researchers used ordinary cameras costing only a fraction. The dual-camera is necessary for capturing vibrations from moving objects, such as the movements of the instrument when the musician is playing it, while at the same time, sensing individual sounds from many other points.

The team claims they have improved the optical microphone to make it more usable and practical. They claim to have improved the quality while reducing the expenses.

According to the team, the system operates with two types of shutters—a global shutter and a rolling shutter. An algorithm analyzes the difference in speckle patterns between the two streams of video. It converts the differences into vibrations for the reconstruction of the sound.

A speckle pattern is a result that coherent light or laser generates after its reflection off a rough surface. By aiming a laser beam at the vibrating surface, the team created the speckle pattern. This speckle pattern changes with the changes on the surface as it vibrates. The rolling shutter rapidly scans the speckle pattern from top to bottom and produces the image by stacking rows of pixels one on top of the other. At the same time, a global shutter captures the entire speckle pattern in a single instance.

Comparing Polyimide Flex Heaters and Silicone Rubber Heaters

Commercial, industrial, military, and aerospace applications use flexible heaters to deliver particular amounts of heat to specific places. The heaters serve multiple purposes, starting from warming food in cafeterias, drying the condensation on aerospace control panels, to controlling temperatures in medical equipment.

These tiny heaters are unique in the sense they are flexible. It is possible to bend them without compromising their heating operations. As flex heaters are very thin, they can squeeze into inter-component space without dislodging. However, the types of materials that make up these heaters impose certain limitations. These are temperature limitations, and the limitation on how much they can bend. Understanding these limitations is necessary for creating designs suitable for the application.

Flexible heaters are typically made from two types of materials—Polyimide and silicone rubber. The thickness of the materials used defines the amount the heater can safely bend without damage. Polyimide flex heaters with etched foil heating elements can be as thin as 0.0007 inches. This thickness allows Polyimide flex heaters to bend around multiple curves within the application.

In contrast, silicone rubber flexible heaters, with etched foil elements, can only go down to a thickness of 0.03 inches. Those with wire-wound elements can at best be 0.056 inches thin. Therefore, although the heater with etched foil elements can have a bend limitation of 1.5 inches, those with the wire-wound elements can bend still less.

Therefore, applications with curved and bent surfaces prefer using Polyimide flex heaters, and those with flat surfaces can do with either Polyimide or silicone rubber.

The range of temperatures offered by a flexible heater depends on the elements and the types of materials it uses. The application defines the temperature desired from the flex heater, depending on the ability of the system to remove the heat and disperse it away from the heater. The heat transfer is important to prevent the heater from overheating and malfunctioning.

Silicone heaters have an operating range of -70 °F (-56.66 °C) to +400 °F (204.44 °C). This makes them ideal for medium to higher temperature applications. However, they tend to fail if the environment cools below the minimum temperature.

On the other hand, Polyimide flex heaters can operate between -320 °F (-195.55 °C) and +392 °F (+200 °C). This makes Polyimide flex heaters suitable for applications working in very low temperatures, such as in spacecraft and satellites. They can help keep electronics functioning in such low temperatures.

Apart from the outer silicone rubber or the Polyimide covering, there are other structures also that add to the overall thickness. These are the solder tabs, wire connections, and other electronics that must connect to the heater.

Both silicone and Polyimide flex heaters with etched foil elements can have a maximum size of 10 X 70 inches. Their size cannot be larger as the heat produced will not be uniform. On the other hand, wire-wound elements can be as big as 36 X 144 inches. However, the wire-wound elements are strictly for silicone heaters, and suitable for large applications.