PARIS — Design engineers living in Silicon Valley have long viewed fully-depleted silicon on insulator (FD-SOI) like the story of the boy who cried wolf. Its massive adoption is always around the corner but never really here — at least not in the Valley.
In contrast to conventional bulk CMOS technology that chip giants like Intel continue to use for each process node, FD-SOI is something “new” and “foreign” for many U.S. designers. The absence of an FD-SOI ecosystem was always a reason for the naysayers to dismiss the technology. They would certainly never gamble on it.
Nonetheless, FD-SOI has champions like NXP Semiconductors and STMicroelectronics in Europe. Earlier this year, NXP revealed plans to go all in with FD-SOI, starting with its lowest power general-purpose applications processors, called i.MX 7ULP.
Common thread: IoT
Meanwhile, new developments are unfolding in Asia, with Globalfoundries naming names among those embracing FD-SOI.
Companies fingered by Globalfoundries as its FD-SOI partners include Taiwan’s Andes Technology Corp., China’s RockChip, Shanghai Fudan Microelectronics Group and Hunan Goke Microelectronics. The common thread? None other than IoT chips.
In particular, Andes Technology’s decision to go with FD-SOI is significant.
Andes and Globalfoundries recently announced that Andes Technology's 32-bit CPU IP cores have been implemented on GF's 22nm FD-SOI (22FDX) technology. GF's 22FDX offers “the optimum combination of performance, power consumption and cost for IoT, mainstream mobile, RF connectivity and networking applications,” according to the foundry.
In an interview with EE Times, Frankwell Lin, president of Andes Technology, said, FD-SOI “will benefit from our promotion in ultra-low power application such as IoT, mobile, low power 5G, battery-backed consumer electronics and more.”
Andes, aided by a minority investment from MediaTek, focuses on the embedded market, with its CPU licensees finding enough niches to get around ARM’s stranglehold. Andes CPU cores apply to touch-panel controllers, WiFi, Bluetooth, FM, GPS controllers, and now sensor hubs targeted at the IoT segment. Incidentally, MediaTek, which is shifting toward IoT chips, is also a licensee of Andes’ IP.
Lin told us that FD-SOI “coincidentally fits Andes Technology’s product development direction.” He said, “Our cores focused on low power and high efficiency have been widely adopted to wireless connectivity fields such as Wi-Fi, Bluetooth, Bluetooth, BT audio, IoT.”
For example, Andes has been addressing connectivity applications with N9 and N13. Additionally, N10/D10 has been used for image processing. Andes’ N7, N8, N9, N10 have been applied to various IoT devices including wearables, smart sensors, Lin said.
“Now with our next generation new cores N25 (32bit), NX25 (64bit) supporting RISC-V, together with Globalfoundries, we will bring more benefit to worldwide customers,” he said.
How so? Lin said, “In consumer electronics, FD-SOI can provide a wide range of performance and power consumption options using body bias. This is particularly true for battery-powered devices.” He said the same applies to touch-panel controllers, because “while a touch controller has a very short duty cycle, it requires significant computing power when it is active doing multi-finger gestures. It also requires very low-power consumption most of the time due to the nature of the end devices.”
Lin concluded: “It happens that the end market for FD-SOI aligns to our product line pretty well. A lot of our lower to mid-end IPs are already adopted in this market including N7, N8 and N9. We’ll see more adoption of Andes cores in the FD-SOI process in the very near future.”
Next page: Globalfoundries bets on China