Official Blog of Silicon Labs

      • The Fastest Isolated Current Sense Amplifier for the World’s Harshest Conditions

        lethawicker | 08/243/2015 | 04:08 PM

        8920blog_1.pngThere’s a problem with the way we measure current in high-voltage systems. While inverters and high-power systems need current information to maintain safe operating conditions, improve system efficiency, and respond quickly to load changes; measuring current on a high-voltage rail can be a real challenge. Sensors have to be electrically isolated from the system controller, sensors have long delays limiting response time, accuracy over temperature ranges is difficult to maintain, and systems are noisy.



        How does the Si8920 isolated amplifier solve for these challenges? Let’s take a look:




        Sensors have to be electrically isolated from the system controller

        Robust galvanic isolation keeps the controller safe even with working voltages up to 1200 V

        Sensors have long delays limiting response time

        Low signal delay means the controller can respond quickly with bandwidth of up to 750kHZ and response times with an unprecedented 0.75 µs signal delay

        Accuracy over temperature ranges is difficult to maintain

        Tiny offset (1 µV/°C) and gain drift insures accuracy over an entire temperature range of -40 to 125°C

        Systems are noisy

        Excellent transient noise immunity, with more than 25 years of field operation expected


        In contrast with traditional amplifiers, the Si8920 is the industry’s fastest isolated current sense 8920blog_2.pngamplifier. It provides precise current shunt measurement for power control systems, including motor drivers and inverters.


        Ideal use cases for the Si8920 include industrial motor drivers, solar inverters, high-voltage power systems, uninterruptible power supplies (UPS) and electric/hybrid-electric (EV/HEV) vehicle systems.


        Here’s an example of an AC Motor Drive that uses the Si8920 to measure current both on the high-voltage DC Link (+), as well as on the legs of the motor.



        For more information on the Si8920, visit our website.

      • The USB and Battery Power Balancing Act

        lethawicker | 08/238/2015 | 03:36 PM

        When designing a portable device, you want to maximize interoperability and user friendliness, so you want to choose an interface like USB. And when you incorporate USB, you also make your gadgets host-agnostic. It doesn’t matter whether your users connect to a PC, an iPhone, or an Android tablet. Therefore, when you want to connect all of these extra gadgets via USB to your battery-powered go-to mobile devices, what was never a concern in the original USB specification – power consumption – suddenly becomes a top priority when choosing a USB-based solution.


        You don’t want to waste the precious battery life of a tablet or laptop just to communicate with the on-board peripherals. And you don’t want to design a simple add-on application for a smart phone that quickly drains its battery.


        By choosing the right USB-enabled hardware, you will be able to develop your device with a much smaller energy footprint since a universal M2M interface allows you to exclude almost all external components.


        USB and the IoT

        In general, only the host can initiate transfers. Even if there is no communication, the host sends keep-alive messages to the device every millisecond. If the device has data available, it will reply. In this active mode, the device has up to 100 mA of power, and the host expects the device to provide an immediate response to any request. When the host stops sending these keep-alive messages for 3 ms, the device should enter a suspend state and immediately reduce its current draw below 3 mA.


        In the suspend state, most of the device can be switched off, and usually we can switch off the most power-hungry parts of the PHY. Even though a 3 mA suspend current should be easily achievable by any modern MCU, there is no reason to keep it that high. MCUs with well-thought-out energy modes, like the Silicon Labs EFM32 Happy Gecko MCU, should be able to achieve less than 3 µA in this mode, including the current draw of the PHY.


        However, in active mode, when inspecting the USB communication of a regular keyboard device, active mode is still not very active; most of the time, the device is just waiting for the host to send data. However, whenever the host requests a response from the device, the response must be immediate; that is why most implementations keep the USB peripheral running at 48 MHz at all times to allow sufficient response time. In this particular example, the lines are idle for 97 percent of the time, even though we are enumerated and active.


        A USB implementation that decides when the clock is needed and for how long is uniquely optimized for battery-powered applications. Silicon Labs now has two patents pending for designs to make the USB interface truly usable in today’s battery-powered IoT world. Energy-efficient communications, even in active mode, are enabled by using crystal-less USB oscillators and by disabling the power-hungry part of USB connectivity between packets, as shown in Figure 3. This innovative approach greatly reduces system-level power consumption and creates a truly universal M2M interface offering exceptional energy efficiency.




        Low-energy USB should be implemented in a way that is completely transparent to developers and to end users. What will be noticeable is significantly reduced power consumption through low-energy modes (LEM), as shown in Figure 4. When this technology is combined with other space- and cost-saving features such as crystal-less USB implementations and clock recovery, developers can realize a truly ultra-low-power universal M2M interface without the need for additional external components.




        EFM32 Happy Gecko—the USB MCU for the Future of the IoT

        When examining the evolution of the USB interface, it’s clear that the next step is to make USB the universal and power-friendly solution for battery-powered devices. MCUs like Silicon Labs EFM32 Happy Gecko make the minute decisions necessary to reduce power consumption dramatically, enabling USB to penetrate markets where it has not yet succeeded to its fullest potential. 

      • Add USB Easy as 1-2-3

        lethawicker | 08/236/2015 | 09:22 AM

        Sometimes we forget to add USB to our designs, or we need USB to access the design more efficiently from our development platform.


        Don’t worry. It’s easy to drop-in USB connectivity to any design—old or new—with the fixed-function CP210x MCU family from Silicon Labs. In fact, you can do it in just three quick steps.


        Step 1 – Connect CP210x EVK to your Windows PC and your Launch Windows driver installer to walk through the wizard to set the driver name and configurations.




        Step 2 – Install the driver on the target device and reboot Windows to recognize it. No additional code writing necessary. 


        This is the set up.  There are two wires that go from my UART ports on the device to the TX and RX ports of the Silicon Labs CP2102 device.  Then the USB goes to the host computer where the terminal is viewed.


        USB 123


        Step 3 – Once the drivers are in place and the device is recognized, open a com port and, USB-am! start sending and receiving USB data.


        com port


        Learn more at the Silicon Labs CP210x Page

        CP210x devices


        Download AN721 for more detailed instructions

        AN721, adding USB walkthrough



        Buy the CP210x EVK to get started

        Evaluation kit



        Customize the USB driver

        Custom driver info


        Feel free to share your thoughts in the comments!

      • Who Shrunk My Sleepy Bee?

        lethawicker | 08/231/2015 | 04:06 PM

        Sleepy Bee

        When we say we’ve made the Sleepy Bee, the most energy-friendly of our Bee family of 8-bit MCUs, smaller, we’re not kidding. It now measures a miniscule 1.72 X 1.66 mm2. The best part of this shrink-ray process is that we’ve preserved the best features:


        • 12 robust capacitive touch channels to add touch sensing to even the most space-constrained environments
        • Ultra low-power consumption achieving a touch detection of ~1 µA
        • A full library of Capacitive Sense features and algorithms in Simplicity Studio
        • Fast wake up at 2 µs
        • Precision clocking to optimize for system and power requirements

        SB1 or SB2—which is Right for You?


        The Sleepy Bee is packaged in two form factors—the SB1 and the SB2. What’s the difference? Let’s take a look.


        The SB1 is great for applications that require:

        • Low power,
        • A small package
        • Robust capacitive sensing

        Some examples include set-top boxes, earphones, instrumentation panels, and keypads.


        The SB2 shines in applications that require:

        • Low power with a low standby current
        • Larger flash capacity for more complex processing
        • An ideal solution to go-between a sensor and a radio

        Examples of applications where you might want an SB2 include hand-held medical devices, remote controls, toys, or product tags.


        The bottom line is that no matter how small we’ve made the Sleepy Bee, you still get an MCU without compromise. Get a starter kit at our website and find out for yourself.


        Sleepy Bee Starter Kit

      • Bluetooth Certification Hassles? We’ve Got It Handled.

        lethawicker | 08/229/2015 | 08:05 AM

        Bluetooth® Smart is a hot ticket in the world of IoT development. Hop straight into the fast lane for developing new solutions with Silicon Labs’ new BGM111 Module. The BGM111 Module super-charges your development with best-in-class integration, flexibility, energy-efficiency and tool-chain support. And when you get to the point where you want to use a System-on-a-Chip (SoC) instead of a module? You’ve got the advantage of an easy upgrade path that makes big headaches into routine changes.


        BGMAbout that Bluetooth Smart pre-certification--the BGM111 Module comes pre-loaded with a compliant Bluegiga Bluetooth 4.1 software stack and profiles, with field-upgradable capability to Bluetooth 4.2 and beyond. Why build your own software stacks and put them through Bluetooth certification when you can let us do it for you?



        In fact, Silicon Labs’ wireless SDK gives you the flexibility to use either a host or fully standalone operations through our easy-to-use Bluegiga BGScript™ scripting language. If you are familiar with BASIC-like syntax, you’re good to go with BGScript, and you’ll be creating Bluetooth applications quickly and without using external MCUs to run the application logic. If you’re thinking that doing all the code execution on the module will reduce your cost and board space while speeding time to market, you’d be right. What’s more, Silicon Labs provides an extensive library of application profiles and examples.


        Find out how to get your development into the fast lane by getting a starter kit at



      • Vote for us and choose your own adventure at SXSW 2016!

        lethawicker | 08/223/2015 | 02:20 PM

        We have not one, not two, but FOUR fantastic panels you can vote for in the 2016 SXSW® PanelPicker®. Here’s how to vote—it’s easy!


        First, you need to create a PanelPicker account and log in to vote. Now that you’re logged in, you can search for Silicon Labs to find our panels. Or, take the easy route and just click the links below.


        Breakfast from a Browser: It’s Morning in the IoT
        Speaker: Greg Fyke



        Aiming Low: Low-Power MCUs for the IoT
        Speaker: Greg Hodgson


        Step Right Up: Design the Next Winning Wearable
        Speaker: Ross Sabolcik


        Which Wireless? Choosing the Right Protocol
        Speaker: Eric Garlepp



        Thanks for voting! Let’s get some serious silicon on the floor at SXSW 2016!

      • 21st Century Packet Networks Need Advanced Network Synchronization Solutions

        lethawicker | 08/222/2015 | 04:25 PM

        Mobile traffic is increasing at an exponential rate due to the popularity of data-intensive services such as video streaming. To expand coverage and increase capacity, network operators are increasingly deploying small cells and pico cells as a solution of choice. These small form factor base stations can be deployed between larger macro base stations to enable network densification in congested, high-traffic urban environments. Cost is critically important given the number of small cells and pico cells that need to be deployed. It is important to note that equipment cost is not the only concern. Low-cost, low-power base stations require cost-effective network synchronization. While conventional synchronization solutions tend to rely on expensive, rigid architectures, recent advancements in digital phase-locked-loop (PLL) technology are now available that greatly minimize the cost and complexity of frequency, time and phase synchronization over packet networks.


        There are three main methods for delivering synchronization over packet networks. The first is Synchronous Ethernet (SyncE), which provides frequency synchronization using physical-layer-based timing. SyncE is defined by the Internet Telecommunication Union Telecommunication Standards Sector (ITU-T) G.8261, G.8262 and G.8264. The second approach involves packet-based timing using IEEE 1588-2008 Precision Time Protocol (PTP)), as defined by ITU-T G.8265. IEEE 1588-2008 PTP provides frequency, time and phase synchronization. Finally, global navigation satellite systems (GNSS) can be used to provide time and phase synchronization.


        Conventional network synchronizer clocks ICs that support synchronization over packet networks rely on chip architectures that borrow heavily from legacy Stratum 3/3E clock IC implementations used in wired networks, which are not optimized for size, power or performance. This trend toward complexity and over-integration runs counter to the wireless industry’s need for simple, low-cost, low-power network synchronization.




        Next-generation network synchronizer solutions like Silicon Labs’ Si5348 clock can be used in low-cost, low-power packet network synchronization applications. The Si5348 clock delivers a solution that is 50 percent smaller, 35 percent lower power, and 80 percent lower jitter than conventional synchronizers. These benefits enable hardware designers to simplify the adoption of packet network synchronization without compromising system-level performance. The Si5348 architecture leverages Silicon Labs’ fourth-generation DSPLL® technology to deliver outstanding jitter performance in a solution that is compliant with IEEE 1588, SyncE and Stratum 3 clocking requirements, enabling the device to be used in a wide variety of timing card and line card clock architectures. The Si5348 clock has been designed to easily interoperate with IEEE 1588 software running on an external host processor, further simplifying system integration.


        The Si5348 clock has three ultra-low-jitter DSPLLs with <130 fs RMS jitter performance. Each DSPLL can be used as a SyncE PLL or as an IEEE 1588 Digitally-Controlled Oscillator (DCO), enabling the Si5348 to be used in multiple IEEE 1588 system topologies, including as a Telecom Grand Master (T-GM), Telecom Boundary Clock (T-BC) or Telecom Slave Clock (T-TSC). In DCO mode, the Si5348 supports low jitter clock steering with ultra-high frequency tuning resolution, providing greater performance than conventional DAC-based solutions.


        The Si5348 clock enables hardware designers to implement a “clock-tree-on-a-chip” solution for SyncE, IEEE 1588 and general-purpose frequency translation. Find out more about the Si5348 on our website.


      • And the Your IoT Contest Winners Are...

        lethawicker | 08/215/2015 | 12:32 PM

        We were privileged to receive dozens of brilliant entries for the Silicon Labs and Digi-Key Your IoT contest. The creativity and invention on show were absolutely amazing. From the top fifteen (determined by your vote), our judges Peter vanCorenland and Skip Ashton chose the following three winners:


        Device Radio—IoT as It Should Be!

        Christian Klemetsson designed this industrial automation solution to connect the real world to applications through virtual wires.


        Apple HomeKit SmartHome and Wellness IoT Development Platform

        Hoang Nhu developed a platform for extending the IoT through all parts of the home, from medication reminders to Smart Power plugs.

        Snappy Modular Robotics for STEM Education

        Snappy Modular Robotics, designed by Ekawahyu Susilo, is a simple, magnetic development platform for STEM education projects, from classroom learning to science fairs.




        Join us in congratulating our three winners, and expect to learn a lot more about their projects as they use their $10,000 in Silicon Labs Components supplied through Digi-Key to bring these ideas to reality.



      • UV Sensors Protect from Harmful Sun Exposure

        lethawicker | 07/210/2015 | 03:27 PM

        Being 6th might not seem like something to make a big fuss about, but when it comes to common types of cancer, melanoma of the skin and its 6th place ranking is something worth considering. Skin cancer can occur anywhere on the body, but it is most common in skin that is often exposed to sunlight. Don’t believe us? Check out this video.



        It's fairly easy to protect yourself from the warming but potentially lethal rays from the sun. Wearing sunscreen or protective clothing helps block UV radiation, but how do you know how much ultraviolet rays you have been exposed to or when excessive levels are reached? Passive and disposable bracelets and portable measuring devices exist today. Because of their disposable nature and lack of user-friendliness, these temporary solutions are not something you would carry with you all day, every day.


        UVsensor1.pngOn the other side of the coin, companies like Basis, Fitbit, Garmin, Misfit and lately Apple provide durable fitness trackers and smart wearables and watches. Traditionally, these devices do a great job at tracking steps and heart rate and even blood oxygen levels. However, they have lagged behind when it comes to including UV exposure to the list of metrics they track.  


        These manufacturers now have the ability to include tiny sensors that measure UV exposure, and actively warn the user of dangerous levels and too much time spent in the sun. Silicon Labs’ Si1132/4x sensor family is the industry’s first single-chip, digital UV index sensor IC solution designed to track UV sun exposure. In addition it supports heart/pulse rate and blood oximetry, and provides proximity/gesture control for smartphone and wearable computing products.


        Silicon Labs’ Si1132/4x UV sensors have won the prestigious EE Times and EDN UBM ACE Award for 2015. We hope to start seeing UV sensing added to the standard measurements of every wearable device, so that no one is ever caught by surprise by their UV exposure again.


        So remember, whether you are playing on the beach or in sunny mountains, make sure you protect yourself and your skin, and check out our award-winning UV sensor


      • Meet the 15 Finalists for the Your IoT Contest!

        lethawicker | 07/209/2015 | 09:55 AM


        We’ll announce the three winners on August 3rd, but until then check out our fifteen finalists. These finalists were determined by number of votes from the community. There are some brilliant ideas here, so make sure to take a look and root for your favorite.


        Check back on August 3rd to find out which three IoT projects will win $10,000 in Silicon Labs components from Silicon Labs and Digi-Key.