About Circuit Cellar Staff

Circuit Cellar's editorial team comprises professional engineers, technical editors, and digital media specialists. You can reach the Editorial Department at editorial@circuitcellar.com, @circuitcellar, and facebook.com/circuitcellar

Rad-Hard MCU Family Meets Space Needs

A new microcontroller that combines specified radiation performance with low-cost development associated with Commercial Off-The-Shelf (COTS) devices is now available from Microchip Technology. Developing radiation-hardened systems for space applications has a history of long lead times and high costs to achieve the highest level of reliability for multi-year missions in a harsh environment. Today, space and other critical aerospace applications require faster development and reduced costs.

The ATmegaS64M1 is the second 8-bit megaAVR MCU from Microchip that uses a development approach called COTS-to-radiation-tolerant. This approach takes a proven automotive-qualified device, the ATmega64M1 in this case, and creates pinout compatible versions in both high-reliability plastic and space-grade ceramic packages. The devices are designed to meet radiation tolerances with the following targeted performances:

  • Fully immune from Single-Event Latchup (SEL) up to 62 MeV.cm²/mg
  • No Single-Event Functional Interrupts (SEFI) which secure memory integrity
  • Accumulated Total Ionizing Dose (TID) between 20 to 50 Krad(Si)
  • Single Event Upset (SEU) characterization for all functional blocks

The new device joins the ATmegaS128, a radiation-tolerant MCU that has already been designed into several critical space missions including a Mars exploration plus a megaconstellation of several hundred Low Earth Orbit (LEO) satellites.

The ATmega64M1 COTS device, along with its full development toolchain including development kits and code configurator, can be used to begin development of hardware, firmware and software. When the final system is ready for the prototype phase or production, the COTS device can be replaced with a pin-out compatible, radiation-tolerant version in a 32-lead ceramic package (QFP32) with the same functionality as the original device. This leads to significant cost savings while also reducing development time and risk.

The ATmegaS64M1 meets the high operating temperature range of -55°C to +125°C. It is the first COTS-to-radiation-tolerant MCU to combine a Controller Area Network (CAN) bus, Digital-to-Analog Converter (DAC) and motor control capabilities. These features make it ideal for a variety of subsystems like remote terminal controllers and data handling functions for satellites, constellations, launchers or critical avionic applications.

To ease the design process and accelerate time to market, Microchip offers the STK 600 complete development board for the ATmegaS64M1, giving designers a quick start to develop code with advanced features for prototyping and testing new designs. The device is supported by Atmel Studio Integrated Development Environment (IDE) for developing, debugging and software libraries.

Microchip Technology | www.microchip.com

Designing a Home Cleaning Robot (Part 2)

Part 2: Mechanical Design

Continuing with this four-part article series about building a home cleaning robot, Nishant and Jesudasan discuss the mechanical aspects of the design.

By Nishant Mittal and Jesudasan Moses
Cypress Semiconductor

In part one (Circuit Cellar 329, December 2017) of this home cleaning robot article series, I discussed the introduction to the concepts of cleaning robots and the crucial design elements that are part of a skeleton design. Apart from that I discussed various selection criteria of the components. In this part, with the help of my colleague Jesudasan Moses, I’ll explore the mechanical aspects of the design. This includes selecting materials, aligning all the components on base, designing the pulleys for optimal performance, selecting motors and so on. The mechanical design for such a system can be very challenging because it’s a moving system and that adds complexity to the process. While this part is focused on mechanical issues and making the base ready, all this paves the way for when we add the “brains” into the system in part three.

DESIGN ELEMENTS

Figure 1 shows the block diagram of the mechanical design for this project. The overall structure of this design requires a base that is strong, but not too heavy. Using a metal base isn’t a good option for this type of system because it would increase the overall weight. Such an increase might mean that a higher torque motor would be required. The next elements are the motors and wheels. We chose to include motors only in the back. Using a front motor would probably be an overdesign for such a system. If you examine professionally designed home cleaning robots—like those I covered in part one—all of them had only the back motors for movement.

Figure 1
Mechanical arrangement of the home cleaning robot

On the front side of the unit, only rollers are added. This gives the system a complete 360-degree freedom of movement. The most important parts of the system are the cleaner and the roller. These are placed toward the center of the system and are controlled using an arrangement of motors and pulleys. In the front of the system, side brushes are added that again are controlled using motors. Now let’s look at the selection of each of the design elements.

Selection of the base shape: The base shape selection is very important because it defines how efficiently your home cleaning robot can clean at corners. A circular base shape is the most recommended option. A circular base enables the robot to move around corners and thereby cover each and every part of the house. That said, for a hobby project like this one, a rectangular base means no advanced tools are needed to cut and shape the base. With that in mind, we chose to use an acrylic material in a square shape for the base.

Motor selection: For our design, we opted for two movement motors on the back of the unit and another motor at the back for the roller pulley. On the front, there are two more motors to move the side brushes. We’ll save the more technical discussion about motor selection in part three. Choice of motor size depends upon the total weight that the front and back need to handle. The total weight should be equalized, otherwise the system won’t remain stable when the robot is moving fast. The placement of the two movement motors should be aligned to their center of axis. That ensures that when the robot is moving straight, it won’t divert its direction. It’s also important to buy those two motors from the same vendor to make sure they share the same mechanical properties.

Wheel Selection: It’s very important to decide on the net height of the system early on. Wheel selection is the deciding factor for the net height. .

Read the full article in the January 330 issue of Circuit Cellar

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!
Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

Mouser Inks Distribution Deal with Onion

Mouser Electronics has signed a global distribution agreement with Onion, a global provider of integrated wireless microprocessor modules and IoT development kits. Through the agreement, Mouser will distribute the Omega2+ device, kits, and accessories, ideal for applications such as home automation, coding education, Wi-Fi media servers, robotics and networking.

The Onion product line, available from Mouser Electronics, revolves around the Omega2+, (shown) an easy-to-use, expandable IoT computer packed with built-in Wi-Fi connectivity, a MicroSD card slot, and a powerful 580 MHz MIPS processor. Though just a fraction of the size of other single board computers, the Omega2+ is a full computer with a Linux operating system, 128 MB of DDR2 memory and 32 MB of flash storage. The device also offers 15 general-purpose inputs and outputs (GPIO), two PWM and two UART interfaces.

Mouser also now stocks a variety of docks and expansion boards, which provide additional functionality to the Omega2+ board. The Expansion Dock powers the Omega2+ and breaks out the GPIOs. The dock also allows engineers to expand their Omega2+ with expansion modules like OLED, relay, and servo. Additionally, engineers can use the Arduino Dock R2 and add the Omega2+ to existing Arduino-based projects. The Arduino Dock R2 is a full Arduino Uno that allows the Omega2 to control the Arduino’s ATmega microcontroller through a serial connection.

The Omega2 Starter Kit and Omega2 Maker Kit both include an Omega2+ board, expansion dock, breadboard, and a variety of components to help engineers quickly get started building circuits. The Maker Kit includes the same components as the Starter Kit and adds two servos, a DC motor, H-bridge chip, buzzer and three expansion boards.

Mouser Electronics | www.mouser.com/onion

Tuesday’s Newsletter: IoT Tech Focus

Coming to your inbox tomorrow: Circuit Cellar’s IoT Technology Focus newsletter. Tomorrow’s newsletter covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your IoT Technology Focus newsletter issue tomorrow.

Not a Circuit Cellar Newsletter subscriber?
Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Embedded Boards.(1/23 Wednesday) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

January has a 5th Tuesday, so we’re bringing you a bonus newsletter:
Displays and Graphics. (1/30) Display technology is where the user interacts with today’s modern embedded electronic devices This newsletter content examines the latest technology and product developments in displays along with the graphics ICs that drive those displays.

Analog & Power. (2/6) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (2/13) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Skylake-Based SBC Runs on 15 Watts

VersaLogic has released the Condor—a high-performance embedded computer that measures only 95 mm x 95 mm x 37 mm and is built around Intel’s 6th generation “Skylake” Core processor. The Condor provides up to six times the processing power of Intel’s Bay Trail processors, while keeping power consumption as low as 15 Watts.The Condor’s on-board TPM security chip can lock out unauthorized hardware and software access. It provides a secure “Root of Trust.” Additional security is provided through built-in AES (Advanced Encryption Standard) instructions.

PR_EPU-4460_HICondor is the latest addition to VersaLogic’s line of EPU (Embedded Processing Unit) format computers. EPUs are designed around COM Express form factors, but are complete board-level computers. They provide all the future flexibility of separate CPU and I/O modules, and are delivered as complete fully assembled and tested units (including heat plate), ready to bolt into a system.

On-board I/O includes two Gbit Ethernet ports with network boot capability, two USB 3.0 ports, four USB 2.0 host ports and two serial ports. One SATA III interface supports high-capacity rotating or solid-state drives. Eight digital I/O lines, I2C and SPI are also available. Two Mini PCIe sockets (one with mSATA capabilities) provide flexible solid-state drive (SSD) options. Systems can be easily enhanced by leveraging the Mini PCIe sockets with plug-in Wi-Fi modems, GPS receivers, MIL-STD-1553, Ethernet, Firewire and other mini cards.

The Condor is designed and tested for industrial temperature (-40° to +85°C) operation and meets MIL-STD-202G specifications to withstand high impact and vibration. For additional reliability, the Condor includes on-board power conditioning which accepts an input of 8 to 30 volts to greatly simplify system power supply design. For additional protection, the conditioner includes Reverse Voltage Protection (RVP) and Over Voltage Protection (OVP) functions.

The Condor, part number VL-EPU-4460, is in stock now. OEM quantity pricing for starts at $1,304 for the Core i3 model with 8 GB RAM.

Versalogic | www.versalogic.com

Voltage Regulator Has Low Quiescent Current

Diodes Incorporated has introduced the AP7381. Operating from a wide input voltage spanning 3.3 V to 40 V, this positive voltage regulator offers ultra-low quiescent current and high accuracy, making it well-suited for use in a variety of applications ranging from USB and portable devices to energy meters and home automation.

MFG_AP7381_SOT89The AP7381 is offered with fixed output voltages of 3.3 V or 5 V to power standard logic device supplies and I/O levels and can operate from an input voltage between 3.3 V and 40 V, which covers most common system power rails. The device provides excellent line and load regulation and features a low dropout voltage of typically 1,000 mV for a 3.3 V output device operating at an output current of 100 mA. An internal voltage reference ensures output accuracy at room temperature is maintained within ±2%.

A low quiescent current of just 2.5 µA minimizes standby power in low-power systems and extends the life of battery-operated products. The AP7381 has a built-in current limit and an over-temperature protection (OTP) function and also features over-current protection, provided by an internal current limit circuit. The AP7381 is available in a SOT89 package (on tape and reel) and in a TO92 package (ammo packed).

Diodes Incorporated | www.diodes.com

Technology and Test Solutions for 5G

Next-Gen Communications

As carriers worldwide prepare for 5G communications, chip suppliers and test equipment vendors are evolving their products to meet the challenges of the 5G era.

By Jeff Child, Editor-in-Chief

The technologies that are enabling 5G communications are creating new challenges for embedded system developers. Faster mobile broadband data rates, massive amounts of machine-to-machine network interfacing and daunting low latency constraints all add to the complexity of 5G system design. Feeding those needs, chip vendors over the past 12 months have been releasing building blocks like modem chips and wideband mixers supporting 5G. And test equipment vendors are keeping pace with test gear designed to work with 5G technology.

With standards expected to reach finalization around 2020, 5G isn’t here yet, But efforts worldwide are laying the groundwork to deploy it. For its part, the Global mobile Suppliers Association (GSA) released a report in October 2017 entitled “Evolution from LTE to 5G.” According to the report, there is a frenzy of testing of 5G technology and concepts worldwide. The GSA has identified 103 operators in 49 countries that are investing in 5G technology in the form of demos, lab trials or field tests that are either under way or planned. Operators are sharing their intentions in terms of launch timetables for 5G, or prestandards 5G. The earliest launch dates currently planned are by operators in Italy and the US. Those early launches are necessarily limited in scope to either specific applications, or in limited geographic areas where they will function as extended commercial trials. Figure 1 shows the countries and the current planned dates for the earliest 5G launches in those countries.

FIGURE 1
Here is a map of pre-standards and standards-based 5G network plans announced. It shows the countries and current planned dates for the earliest 5G launches in those countries. (Source: Global mobile Suppliers Association (GSA)).

THE BIG PLAYERS

Intel and Qualcomm have been the big players to watch for 5G enabling technologies. In October 2017, Qualcomm Technologies, a subsidiary of Qualcomm, hit a significant milestone successfully achieving a 5G data connection on a 5G modem chipset for mobile devices. The Qualcomm Snapdragon X50 5G modem chipset achieved speeds and a data connection in the 28 GHz mmWave radio frequency band. The solution is expected to accelerate the delivery of 5G new radio (5G NR) enabled mobile devices to consumers. Along with the chip set demo Qualcomm Technologies previewed its first 5G smartphone reference design for the testing and optimization of 5G technology within the power and form-factor constraints of a smartphone.

The 5G data connection demonstration showed the chip set achieving Gigabit/s download speeds, using several 100 MHz 5G carriers and demonstrated a data connection in the 28 GHz millimeter wave (mmWave) spectrum. In addition to the Snapdragon X50 5G modem chipset, the demonstration also used the SDR051 mmWave RF transceiver IC. The demonstration made use of Keysight Technologies’ new 5G Protocol R&D Toolset and UXM 5G Wireless Test Platform. Qualcomm Technologies was the first company to announce a 5G modem chipset in 2016. The Snapdragon X50 5G NR modem family is expected to support commercial launches of 5G smartphones and networks in the first half of 2019. …

Read the full article in the January 330 issue of Circuit Cellar

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!
Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

DesignCon Registration is open! Get your free pass today!

Get your FREE pass, and join 5,000 industry pros in Silicon Valley.

The Nation’s Largest Event for Chip, Board & Systems Design Engineers Returns!

DesignCon is back January 30–February 1. Register for your free expo pass to join 5,000 of your peers in Silicon Valley.

PLUS! The DesignCon conference — created entirely by engineers for engineers — is once again fully loaded with can’t-miss industry insights.

Use promo code KCK when you register to save 20% on All-Access conference pass!

Register Now

DesignCon c/o UBM
2901 28th St.
Santa Monica, CA 90405
http://designcon.com/

Qseven Card Sports Renesas RZ/G1M

iWave has announced a System-On-Module (SOM) based on Renesas RZ/G1M embedded processr. RZ/G1M SOM is Qseven R2.0 compatible industrial grade CPU module. Called the iW-RainboW-G20M, this SOM module supports 1 GB DDR3 RAM, 4 GB eMMC Flash and 2 MB SPI NOR Flash. Expandable memory is optional. The module also includes on SOM Gigabit Ethernet PHY, Micro SD slot and USB HUB.

renesas-rz-g1-mpu-embedded-boardRenesas’s RZG1M processor supports dual cortex A15 core operating at 1.5 GHz core and includes 64-bit DDR3 interface at 800 MHz. These features provide higher performance for applications such as image processing of multiple video streams and video sensing. The high-speed on-chip integrated USB 3.0, PCIe, Gbit Ethernet and SATA peripherals allows easy expansion of functionality without the need for external components. The RZ/G1M processor supports full HD hardware encode and decode processing up to 1,080 at 60 frames/s, dual display and three channel video input ports. The built-in PowerVR SGX544MP2 Graphics core at 520 MHz allows the user to develop highly effective user interfaces.

The RZ/G1M SOM is supported Linux 3.10 LTSI with Android BSP support to come. To enable quick prototyping of RZG1M SOM, iWave systems supports RZ/G1M development kit with comprehensive peripheral support. This will help customers to save up to 60% of new product development cycle using the RZ-G1M MPU.

iWave Systems Technologies | www.iwavesystems.com

Tuesday’s Newsletter: Microcontroller Watch

Coming to your inbox tomorrow: Circuit Cellar’s Microcontroller Watch newsletter. Tomorrow’s newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your Microcontroller Watch newsletter issue tomorrow.

Not a Circuit Cellar Newsletter subscriber?
Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

IoT Technology Focus. (1/16) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Embedded Boards.(1/23) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

January has a 5th Tuesday, so we’re bringing you a bonus newsletter:

Displays and Graphics. (1/30) Display technology is where the user interacts with today’s modern embedded electronic devices This newsletter content examines the latest technology and product developments in displays along with the graphics ICs that drive those displays.

3.5″ Board Designed Rugged Environments

AAEON has launched the GENE-SKU6 W1, a 3.5-inch subcompact board with the specifications needed to handle harsh, unstable conditions. When hardware is used for outdoor, factory automation, or in-vehicle applications, you can’t always be sure that its DC input will remain stable. Because businesses can’t afford for their systems to shut down, they need computers that can withstand power fluctuations and keep on running. With that in mind, the GENE-SKU6 W1 has a DC input range of 9 to  36 VDC, so it takes power drops and spikes in its stride and continues operating.

pgal_160922_8bg2utThis rugged subcompact board also has a WiTAS 1 wide-temperature rating, meaning it’s guaranteed to run smoothly in environments as cold as -20°C and as hot as 70°C. This capability is achieved through intelligent design, low-power components and an effective heatsink. Those design features enable the GENE-SKU6 W1 to function as a reliable, fanless solution.

The board’s features include support for 4K resolution and independent DP, DVI, and LVDS display outputs. It has Mini-card and mSATA slots, four USB 3.0 and two USB 2.0 ports, four COM ports and an additional BIO interface enabling board-to-board connection.

AAEON | www.aaeon.com

Op Amp Features Ultra-High Precision

Texas Instruments (TI) has introduced an op amp that combines ultra-high precision with low supply current. The LPV821 zero-drift, nanopower op amp enables engineers to attain the highest DC precision, while consuming 60% less power than competitive zero-drift devices, according to TI. The LPV821 is designed for use in precision applications such as wireless sensing nodes, home and factory automation equipment, and portable electronics.

LS-First-Page

The LPV821 is a single-channel, nanopower, zero-drift operational amplifier for “Always ON” sensing applications in wireless and wired equipment where low input offset is required. With the combination of low initial offset, low offset drift, and 8 kHz of bandwidth from 650 nA of quiescent current, the LPV821 is the industry’s lowest power zero-drift amplifier that can be used for end equipment that monitor current consumption, temperature, gas, or strain gauges.

The LPV821 zero-drift op amp uses a proprietary auto-calibration technique to simultaneously provide low offset voltage (10 μV, maximum) and minimal drift over time and temperature. In addition to having low offset and ultra-low quiescent current, the LPV821 amplifier has pico-amp bias currents which reduce errors commonly introduced in applications monitoring sensors with high output impedance and amplifier configurations with megaohm feedback resistors.

Engineers can pair the LPV821 op amp with the TLV3691 nanopower comparator or ADS7142 nanopower analog-to-digital converter (ADC) to program a threshold that will automatically wake up a microcontroller (MCU) such as the CC1310 SimpleLink Sub-1 GHz MCU, further reducing system power consumption.

Designers can download the TINA-TI SPICE model to simulate their designs and predict circuit behavior when using the LPV821 op amp. Engineers can also jump-start gas-sensing system designs using the LPV821 op amp with the Always-On Low-Power Gas Sensing with 10+ Year Coin Cell Battery Life Reference Design and Micropower Electrochemical Gas Sensor Amplifier Reference Design.

Pre-production samples of the LPV821 op amp are now available through the TI store and authorized distributors in a 5-pin small-outline transistor (SOT-23) package. Pricing starts at $0.80 in 1,000-unit quantities.

Texas Instruments | www.ti.com

LF Resonator Filter

Frequency Measurements

In Ed’s November article he described how an Arduino-based tester automatically measures a resonator’s frequency response to produce data defining its electrical parameters. Here, he examines the results of those measurements and delves into variable series capacitance as measurement aid.

By Ed Nisley

Quartz resonators—also known as “crystals”—normally set the frequency of a clock oscillator circuit to a precise value, but they can also become filters passing analog signals. Because resonators have an extremely high Q, the filters have a very narrow bandwidth and require precise center-frequency tuning. The Arduino-based tester I described in my November 2017 article (Circuit Cellar 328) automatically measures a resonator’s frequency response to produce the data defining its electrical parameters for use as either an ordinary oscillator or a filter isolating the 60 kHz WWVB signal from the surrounding RF clutter.

In this article, I’ll describe the results of those measurements, explain a tester modification to measure the resonator’s response with a variable series capacitance, then show what a resonator filter does to the 60 kHz WWVB preamplifier’s response.

Resonator Frequencies

Over the course of a few months, I bought two lots of 25 quartz tuning fork resonators from eBay, measured all 50 resonators, then converted the data into the histograms in Figure 1. The blue bars show the series resonant frequencies form a reasonably smooth distribution around 59996.1 Hz, 4 Hz below the nominal 60 kHz. A 24 pF series capacitance shifted the resonances upward by 1.7 Hz to produce a similar distribution of the red bars around 59997.8 Hz, showing the resonators behave as expected.

FIGURE 1
The blue bars summarize the series
resonant frequencies of fifty tuning
fork resonators. Inserting a 24-pF
series capacitor shifts the resonant
frequencies upward by about 1.7 Hz.

In contrast, refer to the magnetic sensitivity histograms of the Hall effect sensors in my May 2015 article (Circuit Cellar 298). Those eBay parts apparently came from production-line reject bins, because I got only the parts with responses far from their nominal value. My experience suggests you should not expect cheap electronic parts bought from eBay to meet their specifications and you must measure what you get.

The resonator responses cluster below 60.000 kHz, because they’re intended to be built into oscillator circuits with specific values of external capacitances to set the final frequency. For example, most digital oscillators use a Pierce topology with the resonator connected as a feedback element for a CMOS inverter biased into its linear range and a capacitor from each resonator lead to ground. Those oscillators operate near the resonator’s parallel resonance frequency, with the final frequency pulled slightly higher by the load capacitors. …

Read the full article in the January 330 issue of Circuit Cellar

Don’t miss out on upcoming issues of Circuit Cellar. Subscribe today!
Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

Wearables Drive Demand for Extreme Low Power Solutions

Wearables-Issue-329Wearable devices put extreme demands on the embedded electronics that make them work. Devices spanning across the consumer, fitness and medical markets all need a mix of low-power, low-cost and high-speed processing.


 

 

MCUs & Analog ICs Meet Needs

By Jeff Child, Editor-in-Chief

Designers of new wearable, connected devices are struggling to extend battery life for next-generation products, while at the same time increasing functionality and performance in smaller form factors. These devices include a variety of products such as smartwatches, physical activity monitors, heart rate monitors, smart headphones and more. The microcontrollers embedded in these devices must blend extreme low power with high integration. Meanwhile, analog and power solutions for wearables must likewise be highly integrated while serving up low quiescent currents.

Modern wearable electronic devices all share some common requirements. They have an extremely low budget for power consumption,. They tend not to be suited for replaceable batteries and therefore must be rechargeable. They also usually require some kind of wireless connectivity. To meet those needs chip vendors—primarily from the microcontroller and analog markets—keep advancing solutions that consume extremely low levels of power and manage that power. This technology vendors are tasked to keep up with a wearable device market that IDC forecasts will experience a compound annual growth rate (CAGR) of 18.4% in 2020.

MCU and BLE Combo

Following all those trends at once is Cypress Semiconductor’s PSoC 6 BLE. In September the company made its public release of the PSoC 6 BLE Pioneer Kit and PSoC Creator Integrated Design Environment (IDE) software version 4.2 that enable designers to begin developing with the PSoC 6. The PSoC 6 BLE is has built-in Bluetooth Low Energy (BLE) wireless connectivity and integrated hardware-based security.

According to Cypress, the company had more than 2,500 embedded engineer customers registering for the PSoC 6 BLE early adopter program in just a few months. Early adopters are using the flexible dual-core architecture of PSoC 6, using the ARM Cortex-M4 core as a host processor and the Cortex-M0+ core to manage peripheral functions such as capacitive sensing, BLE connectivity and sensor aggregation. Early adopter applications include wearables, personal medical devices, wireless speakers and more. Designers are also using the built-in security features in PSoC 6 to help guard against unwanted access to data.

The PSoC BLE Pioneer Kit features a PSoC 63 MCU with BLE connectivity (Photo 1). The kit enables development of modern touch and gesture-based interfaces that are robust and reliable with a linear slider, touch buttons and proximity sensors based on the latest generation of Cypress’ CapSense capacitive-sensing technology. Designers can also use the board to add USB Power Delivery (PD) with its Cypress EZ-PD CCG3 USB-C controller. The development kit also includes a 2.7-inch E-ink Display Shield add-on board (CY8CKIT-028-EPD) with thermistor, digital mic and 9-axes motion sensor.

Photo 1 The PSoC BLE Pioneer Kit features a PSoC 63 MCU with BLE connectivity. The kit enables development of modern touch and gesture-based interfaces that are robust and reliable with a linear slider, touch buttons and proximity sensors based using Cypress’ CapSense capacitive-sensing technology.

Photo 1
The PSoC BLE Pioneer Kit features a PSoC 63 MCU with BLE connectivity. The kit enables development of modern touch and gesture-based interfaces that are robust and reliable with a linear slider, touch buttons and proximity sensors based using Cypress’ CapSense capacitive-sensing technology.

Deep Sleep Current Levels

Extreme low power was also the theme behind Microchip Technology’s PIC32MX1/2 XLP family that the company announced in June. The 33-bit PIC32MX1/2 XLP offers current PIC32MX system developers an easy migration path to achieve higher performance at much lower power. It enables both increased functions and longer battery life in portable applications. According to Microchip, the new MCU family increases performance in small pin-count devices with little code rework for existing customers.

Microchip’s XLP technology is designed for wearable technology, wireless sensor networks and other smart connected devices and offers low current operating modes for Run and Sleep, where extreme low-power applications spend 90% to 99% of their time. XLP technology will enable Sleep and Deep Sleep shutdown states on the PIC32MX1/2 XLP devices, enabling Deep Sleep currents down to 673 nA. The devices offer over 40% more performance than the existing PIC32MX1/2 portfolio while reducing average currents by 50%. Figure 1 shows an XLP MCU used in a health/fitness wearable application.

WearablesFigure1

Figure 1 Shown here is a Microchip XLP MCU used in a health and fitness wearable application.

The PIC32MX1/2 XLP family is available in a range of memory configurations with 128/256 kB flash and 32/64 kB of RAM in packages ranging from 28- to 44-pins. They also include a diverse set of peripherals at a low cost including I2S for digital audio, 116 DMIPS performance for executing audio and advanced control applications, a 10-bit, 1 Msps, 13-channel ADC and serial communications peripherals. The PIC32MX2 series also supports USB-device, host and OTG functionality.

In addition to the hardware peripheral features, the series is supported by Microchip’s MPLAB Harmony Software Development Framework, which simplifies development cycles by integrating the license, resale and support of Microchip and third-party middleware, drivers, libraries and RTOSes. Specifically, Microchip’s readily available software packages such as Bluetooth audio development suites, audio equalizer filter libraries, decoders (including AAC, MP3, SBC), sample rate conversion libraries and USB stacks will reduce the development time of wearable device applications.

Transactions with Wearables

Among the new features of some wearable devices is the ability to do contactless transactions. Today’s consumers have become quite comfortable with making secure transactions using their smart devices. As a result, traditional card manufacturers want to extend their offerings into contactless wearable products for uses such as payments, ticketing and access control. These can be difficult to implement within tight size and cost constraints, because conventional separate NFC-radio and security chips demand extra space and complicate design. In addition, wearable form factors tend to need small antennas that can restrict communication performance.

Supporting those capabilities in wearables, ST Microelectronics in October unveiled its technology for easy and secure contactless transactions using electronic wristbands or fashionwear like watches or jewelry. The ST53G System-in-Package solution combines the company’s expertise in Near Field Communication (NFC) and secure-transaction chips. ST’s new ST53G System-in-Package combines a miniaturized and enhanced NFC radio with a secure banking chip in one compact 4 mm x 4 mm module (Figure 2). The company’s proprietary boosted-NFC technology enables wearables with small antennas to deliver a great user experience when interacting with card readers over typical contactless distances.

Figure 2 ST’s ST53G System-in-Package combines a miniaturized and enhanced NFC radio with a secure banking chip in one compact 4 mm x 4 mm module.

Figure 2
ST’s ST53G System-in-Package combines a miniaturized and enhanced NFC radio with a secure banking chip in one compact 4 mm x 4 mm module.

The simplicity of this all-in-one module helps card enables embedded developers to quickly design functional and attractive wearables that can range from fashion items to one-time devices like event wristbands. ST offers an extensive development ecosystem, including radio-tuning tools and pre-defined antenna configurations. The ST53G meets all relevant card-industry standards, including EMVCo compliance, ISO/IEC-14443 NFC card emulation, and MIFARE ticketing specifications. The ST53G can host ready-to-use STPay smartcard operating systems and optional VISA/ Mastercard/JCB-certified banking applications pre-loaded on the secure microcontroller.

Embedded Security for Wearables

The secure banking chip contained in the ST53G System-in-Package leverages ST’s proven ST31G480 secure microcontroller that is based on the ARM SC000 SecurCore processor. It features a secure architecture with a NESCRYPT coprocessor for public-key cryptography and hardware accelerators for algorithms like AES and triple-DES. Extensive anti-tamper protection including an active shield, environmental monitoring, a unique serial number for each die and protection against numerous other attacks are also built-in. These features complement software-based security running on the SC000 core to ensure the strongest possible protection for users’ credentials.

The contactless IC is the STS3922 RF booster, which uses active-load modulation (ALM) to maximize transaction range and omnidirectional radio performance in card-emulation mode. This enables wearable devices to be easy to use—with equal or better device-to-reader positioning tolerance than conventional contactless smartcards—even though a smaller antenna is used. Using ST53G contributes to final device cost optimization because small antennas can be etched onto the PCB at almost zero additional cost. In some cases, a challenging metallic case can itself be used as part of the RF antenna.

Automatic power and gain control, configurable sensitivity, and configurable signal/reader-field phase difference ensure consistent communication over all ranges. These enhance smooth interoperability with different types of readers and terminals including various transportation ticketing systems. The STS3922 has a dedicated secure-MCU wake-up output. That feature enables the ST53G System-in-Package to maximize battery life by powering down when not in use.

Power Regulation for Wearables

Designing today’s wearable devices requires not just low power on the MCU side. They also require sophisticated analog IC solutions that help regulate power and extend battery life as much as possible. Along those lines, Maxim Integrated in March announced its the MAX17222 nanoPower boost regulator with what the company claims is the industry’s highest efficiency and lowest quiescent current (IQ) of only 300 nA (Figure 3). The 0.4V to 5.5V input, 1.8V to 5V output boost regulator with 500 mA input current limit reduces solution size by up to 50% compared to similar products and offers 95% peak efficiency to minimize heat dissipation.

Figure 3 The MAX17222 boost regulator offers a low quiescent current of 300 nA, 0.4V to 5.5V input, 1.8V to 5V output and 500 mA input current limit.

Figure 3
The MAX17222 boost regulator offers a low quiescent current of 300 nA, 0.4V to 5.5V input, 1.8V to 5V output and 500 mA input current limit.

Aside from very low quiescent current, the MAX17222 also minimizes heat dissipation and shutdown current. In True Shutdown mode, the minuscule current draw of 0.5 nA virtually stops battery drain to provide the longest battery life and eliminate the need for external disconnect switches. The MAX17222 is internally compensated and requires only a single configuration resistor and small output filter for a full power solution. For ease of use, the boost regulator comes in tiny, density-optimized 0.88 mm x 1.4 mm 6-bump WLP and 2 mm x 2 mm 6-pin standard µDFN packages. It operates over a -40°C to +85°C temperature range.

Health monitoring wearable devices have their own particular analog design challenges. Targeting such needs, Analog Devices offers a low power, next-generation biopotential analog front end (AFE) which enables smaller, lighter and less obtrusive cardiac monitoring devices with longer battery life. The AD8233 AFE is a fully integrated, single-lead electrocardiogram (ECG) front end designed in one compact, easy-to-use component. Typically, developers need to design ECG front ends from individual components, which can add incremental cost and design time.

Health Monitoring Solution

The highly integrated, out-of-the-box AD8233 AFE eliminates these unnecessary costs and extra time, helping developers get products to market more quickly. Additionally, the device’s 2.0 mm × 1.7 mm size enables the design of wearable health devices that are smaller, lighter and easier to wear. Bulky, heavy and obtrusive monitors can be unpleasant for patients to wear and may even interfere with their everyday lives. Longer battery life is another crucial attribute for cardiac monitors and is vital to ensure continuous monitoring that provides accurate data without the interruption of a recharge or battery replacement. The AD8233 AFE’s low microamp-range power consumption results in greatly extended battery life.

Along with its small size, the single-supply (1.7 V to 3.5 V) AD8233 features extremely low quiescent current of 50 μA (typical); lead on/off detection even while in shutdown mode (less than 1 μA); and 80-dB common-mode rejection ratio (DC to 60 Hz). Electrical noise, a critical specification for cardiac-monitoring devices, is below 10 μV from 0.5 to 40 Hz. The AD8233 also allows for highly flexible filter configurations which are essential to consistent, confident operation in an inherently harsh electrical environment under a range of use cases. These configuarations include a two-pole adjustable high-pass filter, a three-pole adjustable low-pass filter with adjustable gain and an RFI filter. For ease-of-use and flexibility, it also includes an integrated right leg drive (RLD) amplifier with shutdown plus an uncommitted op amp. Analog Devices also offers an evaluation board, reference design, web based filter design tool and Spice model to facilitate design-in and speed time to market.

The AD8233CB-EBZ evaluation board contains an AD8233 heart rate monitor (HRM) front end conveniently mounted with the necessary components for initial evaluation in fitness applications (Photo 2). Inputs, outputs, supplies and leads off detection terminals are routed to test pins to simplify connectivity. Switches and jumpers are available for setting the input bias voltage, shutdown (SDN), right leg drive shutdown (RLD SDN), fast restore (FR) and AC/DC leads off detection mode. The AD8233CB-EBZ evaluation board is a 4-layer board with components mounted on the primary side only. Rubber feet are available on the secondary side for mechanical stability. The layout diagrams are provided as a visual aid and reference design.

Photo 2 The AD8233CB-EBZ evaluation board contains an AD8233 heart rate monitor (HRM) front end conveniently mounted with the necessary components for initial evaluation in fitness applications.

Photo 2
The AD8233CB-EBZ evaluation board contains an AD8233 heart rate monitor (HRM) front end conveniently mounted with the necessary components for initial evaluation in fitness applications.

Wireless Connectivity

Seamless wireless connectivity has pretty much become a given for today’s wearable devices. With that in mind, Cypress Semiconductor in September announced a new combo solution that delivers ultra-low power Wi-Fi and Bluetooth connectivity to extend battery life for wearables and portable audio applications. The new Cypress CYW43012 solution prolongs battery life by leveraging 28 nm process technology to cut power consumption up to 70% in receive mode and up to 80% in sleep mode when compared to current solutions. The solution is IEEE 802.11a/b/g/n-compliant and 802.11ac-friendly, meaning it is interoperable with 802.11ac access points using standard modes. This enables it to offer higher throughput and better energy efficiency, along with the enhanced security and coverage of 802.11ac Wi-Fi networks.

The CYW43012 combo chip’s advanced coexistence engine enables optimal combined performance for dual-band 2.4- and 5-GHz Wi-Fi and dual-mode Bluetooth/BLE 5.0 applications simultaneously. The CYW43012 solution is supported in Cypress’ all-inclusive, turnkey, WICED Studio IoT development platform, which streamlines the integration of wireless technologies for developers. According to Cypress, battery life is a key differentiator for connected devices like wearables. Users demand a great connected experience for longer without having to recharge.

The Cypress WICED Studio IoT development platform features an integrated and interoperable wireless software development kit (SDK). The SDK includes broadly deployed and rigorously tested Wi-Fi and Bluetooth protocol stacks, as well as simplified application programming interfaces that free developers from needing to learn complex wireless technologies. In line with the IoT trend toward dual-mode connectivity, the SDK supports Cypress’ Wi-Fi and Bluetooth combination solutions and its Bluetooth and Bluetooth Low Energy devices. The SDK enables cloud connectivity in minutes with its libraries that integrate popular cloud services such as Amazon Web Services, IBM Bluemix, Alibaba Cloud and Microsoft Azure, along with services from private cloud partners. WICED also supports iCloud remote access for Wi-Fi-based accessories that support Apple HomeKit, which enables hub-independent platforms that connect directly to Siri voice control and the Apple Home app remotely.

Cypress’ WICED Studio connectivity suite actually is MCU-agnostic and provides support for a variety of third-party MCUs to address the needs of complex IoT applications. The platform also enables cost-efficient solutions for simple IoT applications by integrating MCU functionality into the connectivity device. Wi-Fi and Bluetooth protocol stacks can run transparently on a host MCU or in embedded mode, allowing for architectures with common firmware.

As consumers push for more capabilities in their wearable products, they won’t tolerate any reduction in battery life. Along the way, wireless connectivity and embedded security will have to be supported. These conflicting trends will continue to challenge MCU and analog IC vendors to come up with more integrated solutions at ever lower power consumption levels.

RESOURCES
Analog Devices | www.analog.com
Cypress Semiconductor | www.cypress.com
Microchip | www.microchip.com
ST Microelectronics | www.st.com
Maxim Integrated | www.maximintegrated.com

Dotdot Spec to Run on Thread’s IP Network

The Zigbee Alliance and Thread Group have announced the availability of the Dotdot specification over Thread’s IP network. This enables developers to confidently use an established, open and interoperable IoT language over a low-power wireless IP network. This is expected to help unify the fragmented connected device industry and unlock new markets.

Dotdot is the Zigbee Alliance’s universal language for the IoT, making it possible for smart objects to work together on any network. Thread is the Thread Group’s open, IPv6-based, low-power, secure and future-proof mesh networking technology for IoT products. These two organizations have come together to deliver a mature, scalable solution for IoT interoperability that isn’t confined to single-vendor ecosystems or technologies.

Dotdot-over-Thread-no-sub-01The early Internet faced the same challenges as today’s IoT. Currently, connected devices can struggle to deliver a seamless experience because they speak different languages (or in technical terms, use different “application layers”). For the internet, the industry solved this problem with open, universal protocols over IP. Dotdot’s common device language over Thread’s IP network extends this same proven approach to the Internet of Things. With Dotdot over Thread, product and platform vendors can ensure the high-quality, interoperable user experiences needed to drive growth, while IP allows vendors to maintain a direct connection to their device.

It’s important to note that Dotdot over Thread is not another new standard. Dotdot enables the open, mature, and already widely adopted application layer at the heart of Zigbee to work across Thread’s IP network. It uses the same network technology fundamental to the internet. For product managers, new standards represent risk. Dotdot and Thread are backed by global, industry-leading companies and represent two of the most robust, widely deployed, and well-supported connectivity and interoperability technologies, driving billions of products and networks already in homes and offices.

The Dotdot specification is available today to Zigbee Alliance members. Additional resources, including the Dotdot Commissioning Application, will be available in Summer 2018, along with the opening of the Dotdot Certification program from the Zigbee Alliance. Thread launched its 1.1 specification and opened its certification program in February 2017. The Zigbee Alliance and Thread Group now share a number of common authorized test service providers, and are working with them to ensure an efficient, seamless certification process for Dotdot over Thread adopters. More information on this program will be announced soon.

The Zigbee Alliance | www.zigbee.org

Thread Group | www.threadgroup.org