Wearable devices, which first burst onto the market as fitness monitors and first-generation smart watches, have seen serious innovation in the last couple of years. This exciting new category of consumer electronics now includes wearable cameras, smart glasses, smart apparel, and smart accessories.
Usability and design are critical to the success of wearable applications. At its core, a wearable device brings together a processing unit, memory device, sensor(s), and one or more chipsets for communication (Bluetooth, WiFi, etc.). A niche wearable device combines these basic elements in unique ways. As seen with recent wearable launches, if the fit and form are bulky, the product will not take off. To address this issue, Micron is developing memory specifically targeted at the wearable market to facilitate a broad range of sleeker wearable applications to meet user demands.
The wearable market is growing and is expected to generate ~$50B in hardware revenues by 2019 according to a report by Juniper Research (September 2014), and global wearable shipments are projected to reach 45–50 million units in 2015 alone according to a June 17, 2015, Digitimes article. Given the size and scalability of this market, Micron is working with a broad range of chipset vendors (CSVs) and original equipment manufacturers (OEMs), from start-ups to industry leaders, to address memory requirements.
Wearable Application Memory Requirements
In a diverse segment such as this, the end application in most cases drives the design decision around memory. Some of the early low-end fitness monitors and watches were able to satisfy their memory requirements with memory embedded inside a microcontroller unit (MCU). Today, OEMs are packing more attractive features into their devices to differentiate their products and meet customer expectations. This is driving the need for additional external memory, such as Serial Flash (NOR and NAND), PSRAM, and multichip packages (MCPs), which combine RAM and Flash into one package.
While Serial NOR/NAND Flash can meet the memory requirements for low-end wearables, the higher end of the market (cameras and glasses) requires more managed Flash and Mobile DRAM to meet the needs of powerful video/audio processors and colorful displays, and the need for storage (photos and videos).
Fitness bands have been around for a while; however, size, power, and complexity have prevented wider adoption of the technology. Every new generation of fitness bands offers more functionality and better design while shrinking in size and energy consumption—a necessary trend to enable mass market adoption of these devices. An ideal memory solution will include a simple interface, lower pin count, lower power consumption, and adequate security.
Micron’s SPI NOR Flash memory, which is available in densities of 16Mb to 512Mb and in extremely thin CSP packages (0.4mm thickness), can operate at 1.8V, and offers fast boot times, is the primary solution for the current generation of fitness devices.
Micron’s newer SPI NAND Flash memory (1Gb to 4Gb) offers similar features for wearable applications that need higher densities. This solution utilizes highly reliable SLC NAND and is simple to use. Apart from fast write performance and throughput, SLC NAND also offers added security benefits such as OTP and block locking.
These cost-sensitive solutions provide best-in-class performance for fast, secure, ultra-low-power wearable applications.
CSVs and OEMs targeting the mid- to high-end wearables market, which requires the smallest form factor possible, are looking at ePOP as a memory solution because it saves an average of 150mm2 in board space. ePOP is an eMCP (e.MMC + LPDDR2/3) in a package-on-package (POP) design that sits directly on top of the processor versus next to it.
Vertically stacking these solutions not only saves board space, but also results in better overall electrical performance. The shorter routing yields faster signal propagation, reduces noise, and reduces crosstalk. Micron is committed to supporting the wearables market by offering a 12mm x 12mm 4GB e.MMC + 4Gb LPDDR2 ePOP that is available on roadmaps now. Also under consideration is a next-generation 10mm x 10mm ePOP with LPDDR3. (See Micron’s recent blog, The Mobile Package Just Got Smaller, for more information on ePOP solutions.)
This new product category makes up the high end of the wearable market. These are best known for the amazing videos that are shot while surfing, biking, or skydiving. These videos are shot on cameras that have an extremely high-quality lens but the magic of processing these high-speed videos is accomplished by components under the hood, which include powerful processors and high-performance memory. Flash and LPDRAM—either in discrete packages or unique MCPs—are most generally used to cater to the needs of a powerful video/audio processor, colorful display, or storage needs for more data (photos and videos). While the write and read performance of a LPDRAM device helps with processing at low power, the higher density of flash memory provides the necessary space for onboard storage.
Generally, the best wearable devices have long battery life and are small and unobtrusive enough that users forget they are even wearing them. As wearables designs continue to evolve, along with developments in processors, microcontrollers, and packaging methodologies, Micron will continue to innovate for small form factors and low power consumption to enable this exciting category of products.©2015 Micron Technology, Inc. All rights reserved. Information, products, and/or specifications are subject to change without notice. All information is provided on an “AS IS” basis without warranties of any kind. Drawings may not be to scale. Micron, the Micron logo, and all other Micron trademarks are the property of Micron Technology, Inc. All other trademarks are the property of their respective owners.