Low-Power MCUs Extend Battery Life for Wearables

Maxim Integrated Products has introduced the ultra-low power MAX32660 and MAX32652 microcontrollers. These MCUs are based on the ARM Cortex-M4 with FPU processor and provide designers the means to develop advanced applications under restrictive power constraints. Maxim’s family of DARWIN MCUs combine its wearable-grade power technology with the biggest embedded memories in their class and advanced embedded security.

Memory, size, power consumption, and processing power are critical features for engineers designing more complex algorithms for smarter IoT applications. According to Maxim, existing solutions today offer two extremes—they either have decent power consumption but limited processing and memory capabilities, or they have higher power consumption with more powerful processors and more memory.
The MAX32660 (shown) offers designers access to enough memory to run some advanced algorithms and manage sensors (256 KB flash and 96 KB SRAM). They also offer excellent power performance (down to 50µW/MHz), small size (1.6 mm x 1.6 mm in WLP package) and a cost-effective price point. Engineers can now build more intelligent sensors and systems that are smaller and lower in cost, while also providing a longer battery life.

As IoT devices become more intelligent, they start requiring more memory and additional embedded processors which can each be very expensive and power hungry. The MAX32652 offers an alternative for designers who can benefit from the low power consumption of an embedded microcontroller with the capabilities of a higher powered applications processor.

With 3 MB flash and 1 MB SRAM integrated on-chip and running up to 120 MHz, the MAX32652 offers a highly-integrated solution for IoT devices that strive to do more processing and provide more intelligence. Integrated high-speed peripherals such as high-speed USB 2.0, secure digital (SD) card controller, a thin-film transistor (TFT) display, and a complete security engine position the MAX32652 as the low-power brain for advanced IoT devices. With the added capability to run from external memories over HyperBus or XcellaBus, the MAX32652 can be designed to do even more tomorrow, providing designers a future-proof memory architecture and anticipating the increasing demands of smart devices.

The MAX32660 and MAX32652 are both available at Maxim’s website and select authorized distributors. MAX32660EVKIT# and MAX32652EVKIT# evaluation kits are also both available at Maxim’s website.

Maxim Integrated | www.maximintegrated.com

Power Management ICs Reduce Charge Times

Texas Instruments (TI) has introduced several new power management chips that enable designers to boost efficiency and shrink power supply and charger solution sizes for personal electronics and handheld industrial equipment. Operating at up to 1 MHz, TI’s new chipset combines the UCC28780 active clamp flyback controller and the UCC24612 synchronous rectifier controller to help cut the size of power supplies in AC/DC adapters and USB Power Delivery chargers in half. For battery-powered electronics that need maximum charging efficiency in a small solution size, TI also offers the bq25910. It is a 6-A three-level buck battery charger enables up to a 60% smaller-solution footprint in smartphones, tablets and electronic point-of-sale devices.

Designed to work with both gallium nitride (GaN) and silicon (Si) FETs, the UCC28780’s advanced and adaptive features enable the active clamp flyback topology to meet modern efficiency standards. With multimode control that changes the operation based on input and output conditions, pairing the UCC28780 with the UCC24612 can achieve and maintain high efficiency at full and light loads.

The chipset delivers efficient operation at up to 1 MHz, enabling a size reduction of 50% and higher power density than solutions today. Multimode control enables efficiency up to 95 percent at full loads and standby power of less than 40 mW, exceeding Code of Conduct (CoC) Tier 2 and U.S. Department of Energy (DoE) Level VI efficiency standards. For designs above 75 W, engineers can also pair the chipset with a new six-pin power-factor correction (PFC) controller, the UCC28056, which is optimized for light-load efficiency and low standby power consumption to achieve compliance with mandatory International Electrotechnical Commission (IEC)-61000-3-2 AC current harmonic limit regulations. Using features such as adaptive zero voltage switching (ZVS) control, engineers can easily design their systems with a combination of resistor settings and controller auto-tuning.

Leveraging an innovative three-level power-conversion technology, the bq25910 enables up to 50 percent faster charging compared to conventional architectures by dramatically reducing thermal loss. With integrated MOFSETs and lossless current sensing, the bq25910 reduces printed circuit board (PCB) space and allows designers to use small 0.33-µH inductors, saving even more space. The bq25910 enables 95 percent charging efficiency, which could take a standard smartphone battery from empty to 70 percent charged in less than 30 minutes. A differential battery-voltage sense line enables fast charging by bypassing parasitic resistance in the PCB for more accurate voltage measurements, even if the battery is placed away from the charger in the system.

Texas Instruments | www.ti.com

 

Power Alternatives for Commercial Drones

330 Power Drones for Web

Solution Options Expand

The amount of power a commercial drone can draw on has a direct impact on how long it can stay flying as well as on what tasks it can perform. But each kind of power source has its tradeoff.

By Jeff Child, Editor-in-Chief

Because extending flight times is a major priority for drone applications, drone system designers are constantly on the lookout for ways to improve the power performance of their products. For smaller, consumer “recreational” style drones, batteries are the obvious power source. But when you get into larger commercial drone designs, there’s a growing set of alternatives. Tethered drone power solutions, solar power technology, fuel cells and advanced battery chemistries are all power alternatives that are on the table for today’s commercial drones.

According to market research firm Drone Industry Insights, the majority of today’s commercial drones use batteries as a power source. As Lithium-polymer (LiPo) and Lithium-ion (Li-ion) batteries have become smaller with lower costs, they’ve been widely adopted for drone use. The advancements in LiPo and Li-ion battery technologies have been driven mainly by the mobile phone industry, according to Drone Industry Insights.

Batteries Still Leading

The market research firm points to infrastructure as the main advantage of batteries. They can be charged anywhere. While Li-Po and Li-Ion are the most common battery technologies for drones, other chemistries are emerging. Lithium Thionyl Chloride batteries (Li-SOCl2) promises a 2x higher energy density per kg compared to LiPo batteries. And Lithium-Air-batteries (Li-air) promise to be almost 7x higher. However, those options aren’t widely available and are expensive. Meanwhile, Lithium-Sulfur-batteries (Li-S) is a possible successor to Li-ion thanks to their higher energy density and the lower costs of using sulfur, according to Drone Industry Insights.

Photo 1 The Graphene Drone FPV Race series LiPo batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions

Photo 1
The Graphene Drone FPV Race series LiPo batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions

Meanwhile battery vendors continue to roll out new battery products to serve the growing consumer drone market. As an example, in June 2017 battery manufacturer Venom released its new Graphene Drone FPV Race series LiPo batteries. The batteries were engineered for the extreme demands of today’s first person view (FPV) drone racing pilots (Photo 1). The new batteries provide lower internal resistance and less voltage sag under load than standard LiPo batteries. As a result, the battery packs stay cooler under extreme conditions. The Graphene FPV Race series Li-ion batteries are 5C fast charge capable, allowing you to charge up to five times faster. All of the company’s Drone FPV Race packs include its patented UNI 2.0 plug system (Patent no. 8,491,341). The system uses a true Amass XT60 connector that attaches to the included Deans and EC3 adapter.

Chip vendors from the analog IC and microcontroller markets offer resources to help embedded system designers with their drone power systems. Texas Instruments (TI), for example, offers two circuit-based subsystem reference designs that help manufacturers add flight time and extend battery life to quadcopters and other non-military consumer and industrial drones.  …

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

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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.

Massage Vest Uses PIC32

330 Freeman Lead Image

Controlled with an iOS App

These Cornell graduates designed a low-cost massage vest that pairs seamlessly with a custom iOS app. Using the Microchip PIC32 for its brains, the massage vest has sixteen vibration motors that the user can control to create the best massage possible.

By Harry Freeman, Megan Leszczynski and Gargi Ratnaparkhi

As technology continues to make its way into every aspect of our lives, we are increasingly bombarded with more information and given more tools to organize our busy days. For our final project in the Digital Design Using Microcontrollers class at Cornell University, we sought to build technology to help us slow down, enjoy the moment and appreciate our senses. With that in mind, we built a low-cost massage vest that pairs seamlessly with a custom iOS app. The massage vest embeds 16 vibration motors and users can control the vest to create the most comfortable and soothing massage possible. The user first provides their input through the iOS app, which allows for multiple input modes—including custom or preset. The iOS app communicates to a PIC32 microcontroller via a Bluetooth Low Energy (BLE) module and ultimately the PIC32 turns on the vibration motors to complete the user’s requests. A block diagram is shown in Figure 1. Throughout the massage, users can update their settings to adjust to their desires. The complete massage vest costs less than $100—competitive with mass produced massage vests.
330 Freeman Fig 1 for web
Massage vests have historically been used for both pleasure and therapeutic purposes. Several known iOS-controlled massage vests include the iMusic BodyRhythm from iCess Labs and the i-Massager from E-Tek—both presented at the Consumer Electronics Show (CES) in 2013. The former syncs a massage to music for the user’s enjoyment, while the latter provides Transcutaneous Electrical Nerve Stimulation (TENS) as a certified medical device to relieve chronic pain. A group of Cornell students also won an Innovation Award in 2013 from the Cornell University School of Electrical and Computer Engineering for a massage vest called the Sonic Destressing Vest. The Sonic Destressing vest claimed to reduce the serum cortisol levels of its users, potentially reducing the risk of heart disease and depression—among many other chronic issues related to high serum cortisol levels. Those three vests motivated us to build a multi-purpose massage vest that could be extended to provide the particular features of those vests if desired—serving an existing base of users.

This article describes the details of how our massage vest worked so you can build one for yourself. First, we’ll discuss the hardware design that creates the comforting experience the user has with the vest. This will be followed by a discussion of the software that integrates the components together and provides a friendly user interface. Finally, we will conclude with testing and results. …

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

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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.

Integrated Precision Solution for Batteries

Analog Devices has introduced a precision integrated analog front end, controller, and pulse-width modulator (PWM) for battery testing and formation capable of increasing system accuracy and efficiency in lithium-ion battery formation and grading. Compared to conventional technology, the new AD8452 provides 50% more channels in the same amount of space, adding capacity and increasing battery production throughput. The AD8452 uses switching technology that recycles the energy from the battery while discharging and delivers 10 times more accuracy than conventional switching solutions.

AD8452The higher accuracy allows for more uniform cells within battery packs and contributes to longer living batteries in applications such as electric vehicles. It also enhances the safety of manufacturing processes by providing better detection and monitoring to help prevent over and undercharging which can lead to battery failures. The AD8452 delivers bill of material (BoM) cost savings of up to 50% for charging/discharging boards and potential system cost savings of approximately 20%. System simulating demonstration boards will be available and can enable lower R&D engineering cost and shorter time to market for test equipment manufacturers.

AD8452 Features

  • Enables energy recycling battery formation/grading for systems of 20 Ahours or less with up to 95% power efficiency
  • Industry leading precise measurement of current and voltage better than 0.02% over 10⁰C temperature change
  • Solution size 70% smaller than previous product generation

Analog Devices | www.analog.com

January Circuit Cellar: Sneak Preview

The January issue of Circuit Cellar magazine is coming soon. And it’s got a robust selection of embedded electronics articles for you. Here’s a sneak peak.

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Here’s a sneak preview of January 2018 Circuit Cellar:

 

                                     IMPROVING EMBEDDED SYSTEM DESIGNS

Special Feature: Powering Commercial Drones
The amount of power a commercial drone can draw on has a direct effect on how long it can stay flying as well as on what tasks it can perform. Circuit Cellar Chief Editor Jeff Child examines solar cells, fuel cells and other technology options for powering commercial drones.

CC 330 CoverFPGA Design: A Fresh Take
Although FPGAs are well established technology, many embedded systems developers—particularly those used the microcontroller realm—have never used them before. In this article, Faiz Rahman takes a fresh look a FPGAs for those new to designing them into their embedded systems.

Product Focus: COM Express boards
COM Express boards provide a complete computing core that can be upgraded when needed, leaving the application-specific I/O on the baseboard. This brand new Product Focus section updates readers on this technology and provides a product album of representative COM Express products.

TESTING, TESTING, 1, 2, 3

LF Resonator Filter
In Ed Nisley’s November column he described how an Arduino-based tester automatically measures a resonator’s frequency response to produce data defining its electrical parameters. This time he examines the resultsand explains a tester modification to measure the resonator’s response with a variable series capacitance.

Technology Spotlight: 5G Technology and Testing
The technologies that are enabling 5G communications are creating new challenges for embedded system developers. Circuit Cellar Chief Editor Jeff Child explores the latest digital and analog ICs aimed at 5G and at the test equipment designed to work with 5G technology.

                                     MICROCONTROLLERS IN EVERYTHING

MCU-based Platform Stabilizer
Using an Inertial Measurement Unit (IMU), two 180-degree rotation servos and a Microchip PCI MCU, three Cornell students implemented a microcontroller-based platform stabilizer. Learn how they used a pre-programmed sensor fusion algorithm and I2C to get the most out of their design.

Designing a Home Cleaning Robot (Part 2)
Continuing on with this four-part article series about building a home cleaning robot, Nishant Mittal this time discusses the mechanical aspect of the design. The robot is based on Cypress Semiconductor’s PSoC microcontroller.

Massage Vest Uses PIC32 MCU
Microcontrollers are being used for all kinds of things these days. Learn how three Cornell graduates designed a low-cost massage vest that pairs seamlessly with a custom iOS app. Using the Microchip PIC32 for its brains, the massage vest has sixteen vibration motors that the user can control to create the best massage possible.

AND MORE FROM OUR EXPERT COLUMNISTS:

Five Fault Injection Attacks
Colin O’Flynn returns to the topic of fault injection security attacks. To kick off 2018, he summarizes information about five different fault injection attack stories from 2017—attacks you should be thinking about as an embedded designer.

Money Sorting Machines (Part 2)
In part 1, Jeff Bachiochi delved into the interesting world of money sort machines and their evolution. In part 2, he discusses more details about his coin sorting project. He then looks at a typical bill validator implementation used in vending systems.

Overstress Protection
Last month George Novacek reviewed the causes and results of electrical overstress (EOS). Picking up where that left off, in this article he looks at how to prevent EOS/ESD induced damage—starting with choosing properly rated components.

Wearables Drive Low Power Demands

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MCUs & Analog ICs Meet Needs

Wearable 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.

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.

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.

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.  …

Read the full article in the December 329 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.

Flexible Printed Batteries Target IoT Devices

Semtech and Imprint Energy have announced a collaboration to accelerate the widespread deployment of IoT devices. Imprint Energy will design and produce ultrathin, flexible printed batteries that are especially designed to power IoT devices integrated with Semtech’s LoRa devices and wireless RF technology (LoRa Technology). LoRa Technology, with its long-range, low-power capabilities, is regarded by many as the defacto platform for building low-power wide area networks (LPWAN).

ImprintTo help accelerate a next generation of battery technology, Semtech has invested in Imprint Energy. The companies are working closely to target applications that have the potential to create entirely new markets. The Imprint Energy battery enables new applications which have a thin and small form factor and due to the integrated manufacturing process, the batteries are low cost to produce, making high volume deployments feasible.

A key benefit of the Imprint Energy battery technology is the ability to be printed using multiple types of conventional high-volume printing equipment; this enables quick integration by traditional electronic manufacturers in their existing production lines. Test production runs are currently being processed and the resulting batteries are being used in applications prototypes to validate assumptions and engage early adopters.

Imprint Energy | www.imprintenergy.com

Semtech | www.semtech.com

Buck Converter Extends Battery Life of USB Type-C Gear

Maxim Integrated Products has announced the MAX77756, a 24 V, 500 mA, low quiescent current (IQ) buck converter. The product targets developers of multi-cell, USB Type-C products in need high current, dual inputs and I2C support. USB Type-C products must generate an always-on 3.3 V rail to detect USB insertions. Products utilizing the Power Delivery (PD) voltage range (5 V to 20 V) can generate an always-on (1.8 V /3.3 V /5.0 V) digital supply MAX77756_EVKit_imagerail for the port controller using the MAX77756 step-down converter. In addition, the MAX77756 has a 2 0 μA quiescent current that extends battery life by reducing idle power consumption. To simplify the system design, the MAX77756 has a dual input ideal diode ORing circuit that allows the chip to power from the external USB source if the battery is empty.

Multi-cell battery-operated devices—such as ultrabooks, laptops, tablets, drones and home automation appliances—can easily evolve to Type-C with PD using the flexible MAX77756 power supply. The MAX77756 has a unique combination of wide input voltage range, low quiescent current, higher current load, dual input, and I2C for flexibility and programmability. There is also a default power mode if customers do not want to use the I2C bus. The MAX77756 is a robust IC with short-circuit and thermal protection, 8ms internal soft-start to minimize inrush current, proven current-mode control architecture, and up to 26V input voltage standoff.

Key Advantages

  • Low quiescent current: 1.5 μA Buck and 20 μA MUX for always-on operation
  • High efficiency: Up to 92% with integrated power MUX
  • Small solution size: 2.33mm x 1.42mm 15-bump WLP; no external Schottky array needed
  • Wide input voltage: Operates on full VBUS range (5 V – 20 V) and VBATT (2S, 3S, 4S Li+)

MAX77756 is available from stock and priced at $0.65 (10,000+)..An evaluation board MAX77756EVKIT# (see photo) is available from stock and priced at $70

Maxim Integrated Products | www.maximintegrated.com