Wearables Drive Low Power Demands

320 Wearablese Lead Image for Web

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

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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

Integrated Precision Solution Aids Battery Manufacturing

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

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