analog

By Sowmyan Rajagopalan, Founder and CTO, Thalia Design Automation FD-SOI is receiving significant traction with analog designers, but analog IP reuse often equates to tough choices. Porting chips from bulk to FD-SOI or creating new chips on FD-SOI means making decisions on porting existing bulk IP or starting from scratch. To invest the time and resources in reusing an analog IP requires a judgement call on the potential returns from the market and the time it takes to get the IP to that market to generate revenue is key – if a competitor's project hits the market first, then the potential returns are greatly diminished. There is also a need to understand the differences in process technologies and the impact those differences have on the efficient reuse of analog IPs. All this means that the demands on resources and time are high. Decisions, decisions A typical decision fork faced by many companies is whether to design new IPs, or if they should instead build a portfolio of analog IPs. Given the opportunity cost, availability of resources, time and resources needed for each option means that doing both is a difficult option. Both have their advantages; designing new IPs allows companies to branch out and address new sectors or markets. New IPs often demand higher revenues and engages in-house designers as the work, by its nature, is more innovative and challenging. On the other hand, building a portfolio of analog IPs allows companies to expand in an existing market, bringing stabilisation and strengthening revenues from existing product sectors. But why should you have to choose when there’s a third option? Have your cake and eat it It is difficult for a company to drive both options internally – not least because there’s a paucity of good analog designers in the market, and the opportunity cost is simply too high. However, the good news is that firms like Thalia have the specialist expertise and toolsets required build a portfolio of analog IP, saving time and investment while in-house designers focus on new IP design. Looking back Over the last 18 months, there has been a rapid uptake of FD-SOI process technologies. With production at foundries such as GlobalFoundries and Samsung now in full swing, more and more analog designers are reaping the benefits of FD-SOI. At Thalia we’ve been at the forefront of some of these changes, having worked with multiple customers on projects that use FD-SOI technology. [bctt tweet="More more analog designers are reaping the benefits of #FDSOI. At Thalia we’ve been at the forefront of some of these changes, having worked with multiple customers on projects that use FD-SOI technology. - @Thalia_IP_Reuse CTO " username="soiconsortium"] Driving the shift to FD-SOI [caption id="attachment_34410" align="alignright" width="347"] (Courtesy: STMicroelectronics)[/caption] This figure contrasts the structures of traditional bulk planar and SOI type transistors. The main difference is the inclusion of a buried oxide layer that isolates the channel of the transistor from the bulk silicon of the substrate. This results in a very thin, controllable channel structure, with much lower leakage currents being ‘lost’ into the device substrate than traditional alternatives. This in turn improves two key figures of merit for the device. First, standby power consumption is dramatically reduced. Second, the threshold voltage is much more predictable and controllable – yields are improved, and power/performance tradeoffs via voltage scaling are more easily enabled. The penalty is that FD-SOI transistors are generally not so fast. But one other feature of the technology – particularly important for mixed signal and analog designs – allows smart designers to mitigate this effect. Biasing the body structure at a different voltage to the source enables the designer to trade speed for power: a reverse bias increases the threshold voltage of the device, making it slower, but reducing leakage current; conversely, forward biasing reduces the threshold voltage, increasing the speed of the device, at the cost of power. Design migration Thalia has worked on a number of projects that utilize SOI technologies. A recent RF front end for Bluetooth Low Energy (BLE), for example, used exactly the techniques I have outlined above. We migrated an entire subsystem design, composed of around 30 blocks (including ADCs, PLLs, mixers, amplifiers and power controllers), to a 28nm Samsung FD-SOI process. [caption id="attachment_34412" align="alignright" width="451"] Click on this slide to see a YouTube video of the full Thalia presentation given at the Design Reuse FDSOI Virtual Event in March 2020.[/caption] The circuit was verified for compliance with design specifications. Design changes were implemented to ‘nudge’ the design to meet the requirements. And we made full use of the body biasing techniques I have already outlined. We used reverse body biasing to keep leakage as low as possible in parts of the circuit in which speed was not a factor; and, where speed was a key requirement, implemented forward gate biasing to increase performance. We’re expecting increasing numbers of customers to start moving their analog and mixed signal designs to SOI technologies in the coming months and years. The process is not without its challenges: but with an intimate knowledge of circuit design and optimization, and of the subtleties of the processes themselves, there are substantial advantages to be reaped. Technology analyzer – identifying the root cause when circuits fail A large part of the effort involved with migrating an IP from one technology to another is involved with qualifying the IP in the target technology; if a block doesn’t meet the requirements of the target technology, it won’t function. Identifying the cause of this – the technology characteristics that cause it – and then addressing them is key to a successful outcome. Whenever a key specification is not being met in the target technology, we have to determine which process technology or circuit characteristic is causing this. By using our automated technology analyser, we can take a design-centric approach to analyse and compare base and target technologies to see where the process technologies are similar and where they differ the most. The technology analyser considers both first and second order effects including FT, gm/id, Vdsats among others. Using this technology, we can identify which characteristics differ between the origin and target technologies. With traditional methods, identifying differences in characteristics would be time consuming, but our technology analyzer gives a clear and rapid identification of the issues, allowing us to fix any mis-matched topologies and achieve a functioning result in the target technology. The reality? IP reuse is not a dream or a myth Our platform comprises three elements – Technology, Methodology and Design Expertise. Using this trifecta, we have been able to deliver IPs in different technologies, nodes and with improved characteristics. The AMALIA technology consists of four elements: a technology analyzer, schematic porting, design enabler and layout migration. Tech analyzer: Using a design-centric approach, the platform addresses key first and second order effects of process technologies and extracts and compares characteristics between base and target technologies to provide the user with clear inputs on how similar the technologies are. Automated schematic porting: Taking the inputs from the analyzer and generates a circuit in the target technology. This circuit can then be verified for response and characteristics. Design enabler: Once the circuit design for the target technology is correct, the design enabler and our team of experienced designers can nudge the circuit back into specification. Layout migration: The final stage is focussed on putting together the base layout framework which is then expanding on by our experienced layout designers. Who we are?We are Thalia Design Automation. I founded Thalia in 2011, with the aim of improving the efficiency and process cost of analog circuit design and to rollout an analog IP reuse platform. We’ve worked with vendors, numerous foundries and different nodes and have design centres in Germany and India with our headquarters in the UK. We have successfully rolled out an analog IP reuse platform that combines smart technology, a smart methodology and our smart and experienced resources to streamline the IP reuse process. In doing all this, Thalia regularly provides customers with a time saving of around 50% compared to a traditional circuit redesign. And as I stated at the beginning of this article, achieving a faster time to market is key to maximizing revenues from any IP.

[caption id="attachment_12150" align="alignright" width="252"] Manuel Sellier, Product Marketing Manager at Soitec[/caption] Manuel Sellier, Product Marketing Manager at Soitec for the FD-SOI (and some other) SOI product lines has written an absolutely terrific primer entitled FD-SOI: A technology setting new standards for IoT, automotive and mobile connectivity applications. It's in the August edition of the GSA Forum (the GSA is the Global Semiconductor Alliance). If you know anyone who needs to quickly glean an understanding of FD-SOI that is both in-depth and broad, you'll want to share this piece with them right away. Before joining Soitec, Sellier was a chip designer at ST, where he gained deep experience designing FD-SOI chips. What's more, he holds a Ph.D. in the modeling and circuit simulation of advanced MOS transistors, including FD-SOI and FinFETs. So, he really knows his stuff. But don't worry that this might be too technical: Sellier's writing is thoroughly accessible (and engaging!) for anyone in the industry. He starts with the wafer history, then quickly moves on to the features from the designer's standpoint. And he puts it all in a business perspective. I can't recommend this piece enough – even if you think you know everything already yourself, you're sure to learn something new.

Good news: there are far fewer bigoted extremists out there when it comes to FD-SOI vs. FinFETs. People want the best technology for their application. It's that simple. That's a key piece of news from the updated survey by Dan Hutcheson, CEO of VLSI Research, which he presented in the afternoon session of the SOI Consortium's 2018 SOI Symposium in Silicon Valley The afternoon then featured presentations by foundry partners, which I'll cover here. Also in the afternoon were presentations by wafer-maker Simgui, some innovative start-ups leveraging FD-SOI for custom SoCs and the final panel discussion. I'll cover those in Part 3 of this series. BTW, if somehow you missed my coverage of the morning sessions about very cool new products and projects from NXP, Sony, Audi, Airbus and Andes Technology, be sure to click here to read it. The presentations are starting to be posted on the SOI Consortium Events page – but some won't be. Either way, I'll cover them here. VLSI Research A couple years ago at the annual SOI Symposium in Silicon Valley, Dan Hutcheson presented results of a survey he did (ASN covered it – you can still read about it here). At the 2018 event, he presented an update, which is now posted. You can get it here. The FD-SOI roadmap and IP availability are no longer issues for decision makers, he found. The 14nm branch – do you go FinFET or FD-SOI? – is gone. “Fins and FD are complementary,” he observed. Most people said they'd consider using both and running two roadmaps, choosing whichever technology is appropriate to a given design. [caption id="attachment_11841" align="alignnone" width="1000"] (Courtesy: VLSI Research, SOI Consortium)[/caption] From a transistor viewpoint, the top reasons to choose FD-SOI is that it's better for analog and has lower leakage/parastics. It's perceived as better for complex, high mixed-signal SoCs, and especially for RF and sensor integration. In fact, people see RF as the new mixed-signal, wherein FD-SOI is uniquely positioned for 5G and mmWave. From a business viewpoint, FD-SOI is perceived to have real advantages. In particular, FD-SOI wins when it comes to keeping down design costs, manufacturing costs and time-to-market. IoT is still the hottest target market for FD-SOI, to which he adds high growth expected in automotive and medical. Samsung With 20 tape-outs in 2018, Samsung is seeing an acceleration in its FD-SOI business. “The trend is healthy,” said Hong Hoa, SVP of the company's foundry business. FD-SOI, he continued, is on a “differentiation path.” Samsung's 28nm FD-SOI process, called 28FDS is at full maturity with very strong yields. They're seeing more customers and a wider range of applications. The design infrastructure, silicon-verified IP and methodologies are also all mature. They have optimal implementation and verification guidelines for body bias design, a body bias memory usage guide, and a body bias generator integration guide. The process supports Grade 1 automotive, and will be qualified for Grade 2 in a few weeks. FD-SOI, Hoa reminded the audience, offers superior RF performance compared to both planar bulk and 14nm FinFET. The Samsung strategy is to first provide a base for for the FD-SOI process, then add RF and eMRAM. The base for 28nm was done in 2016; they added RF in 2017 and eMRAM this year. The Samsung platform for IoT applications integrates both RF and eMRAM to support multi-function needs in a single platform. Lead customers are already working with eMRAM in their designs, he added. (BTW, Samsung has a really nice video explaining their eMRAM offering – you can see it on YouTube here.) The basic PDK for the Samsung 18nm FD-SOI process (18FDS) will be available in September 2018, with full production slated for fall of 2019. It will deliver a 24% increase in performance, a 38% decrease in power, and a 35% decrease in area for logic. RF for the 18FDSplatform will be ready by the end of this year, and eMRAM beginning in 2019. GlobalFoundries With design wins from 36 customers underway, 12 of which are taping out in 22FDX (GF's 22nm FD-SOI process) this year, the market has validated FDX for differentiation, said GF SVP Dr. Bami Bastani. And indeed, designers are using it for a wide array of applications across North America, Europe, Asia/Pacific and Japan. Customers in the North America are designing in 22FDX for NB-IoT, industrial, RF/analog, mobile, network switches and cryptocurrency applications. In Europe, it's more or less the same plus automotive/mmWave, optical transmission, wireless BTS and AI/ML. In Asia Pacific/Japan the mix is similar to Europe. Bastani sees the three big enablers as the the strengths of the roadmap, the ecosystem and multi-sourcing from Dresden and Chengdu (where they're already equipping the cleanrooms). He also tipped his hat in acknowledgment to the partnership with FD-SOI wafer supplier Soitec, noting that they have gone the extra mile to match GF's requirements. So that was the first part of a great afternoon. As mentioned above, my next post (part 3) will cover a very informative presentation by wafer-maker Simgui on the markets in China, plus talks by some innovative start-ups leveraging FD-SOI for custom SoCs and the final panel discussion.

Following the immense success of last year's FD-SOI training day in Silicon Valley, the SOI Consortium has another one planned for the end of April this year. If you want to start learning how to leverage FD-SOI in your chip designs, this is a great place to start. Click here for information on how to sign up. ST Fellow Dr. Andreia Cathelin has put together another great line-up. World renowned professors and experts from industry will deliver a series of four training sections of 1.5 hours each, focused on energy efficient and low-power, low-voltage design techniques for analog, RF, high-speed, mmW and mixed-signal design. You'll learn about design techniques that take full advantage of the unique features of FD-SOI, including body biasing capabilities that further enhance the excellent analog/RF performances of these devices. Each section of this training day will take you through concrete design examples that illustrate new implementation techniques enabled by FD-SOI technologies at the 28nm and 22nm nodes – and beyond. The design examples will cover basic building blocks through SoC implementations. A global Q A session will close the day. Here's a little more info on how the day will unfold. Click on the slides to see them in full screen. Morning sessionsFDSOI-specific design techniques for analog, RF and mmW applications - Andreia Cathelin, Fellow, STMicroelectronics [caption id="attachment_11714" align="alignleft" width="300"] Quick preview from Andreia Cathelin's FD-SOI training session (Courtesy: STMicroelectronics, SOI Consortium)[/caption] Andreia Cathelin is ST's key design scientist for all advanced CMOS technologies, and is arguably the world's leading expert on leveraging FD-SOI in high-performance, low-power RF/AMS SoCs. Her course will first present a very short overview of the major analog and RF technology features of 28nm FDSOI technology. Then the focus moves to the benefits of FD-SOI technology for analog/RF and millimeter-wave circuits. She'll give design examples such as analog low-pass filters, inverter-based analog amplifiers and 30GHz and 60GHz Power Amplifiers, as well as mmW oscillators. There will be particular focus on the advantages of body biasing and special design techniques offering state-of-the-art performance. Circuit Design Techniques in 22nm FD-SOI for 5G 28GHz Applications - Frank Zhang, Principal Member of Technical Staff, GlobalFoundries [caption id="attachment_11716" align="alignright" width="300"] Quick preview from Frank Zhang's FD-SOI training session (Courtesy: GlobalFoundries, SOI Consortium)[/caption] Frank Zhang has designed chips using GF's 22nm FD-SOI (22FDX) process for WLAN, 5G cellular and automotive radar applications. His course will focus on how to take advantages of FD-SOI’s high-frequency performance at relatively low-current density to design high performance RF/mmWave circuits. Examples circuits include a 28GHz LNA, a 28GHz PA and an RF switch for 5G applications. The FD-SOI advantages such as low capacitance, high breakdown voltage and high-output impedance will be exploited in these design examples. This course will also discuss how to extend these techniques to applications at higher frequencies and/or higher current densities that are subject to extreme temperatures and EM requirements. Afternoon sessionsEnergy-Efficient Design in FDSOI - Bora Nikolic, Professor, UC Berkeley [caption id="attachment_11715" align="alignleft" width="300"] Quick preview from Bora Nikolić's FD-SOI training session (Courtesy: UC Berkeley, SOI Consortium)[/caption] Borivoje (“Bora”) Nikolić is known as one of the world’s top experts in body-biasing for digital logic (he and his team have designed more than ten chips in ST’s 28nm FD-SOI.) If you missed it, his team's RISC-V chip was cited as one of Dr. Cathelin's “Outstanding 28nm FD-SOI Chips Taped Out Through CMP” – read more about that here. His talk at the training day will present options for energy-efficient mixed-signal and digital design in FD-SOI technologies. He'll explain how to generate body bias and use it to improve efficiency, with examples in RF and baseband building blocks, temperature sensors, data converters and voltage regulators. The techniques will be presented in the context of UC Berkeley's latest RISC-V-based SoC, designed to operate in a very wide voltage range using 28nm FD-SOI. mm-Wave and Fiber-Optics Design in FD-SOI CMOS Technologies - Sorin Voinigescu, Professor, University of Toronto [caption id="attachment_11713" align="alignright" width="300"] Quick preview from Sorin Voinigescu's FD-SOI training session (Courtesy: U. Toronto, SOI Consortium)[/caption] Sorin Voinigescu is a world renowned expert on millimeter-wave and 100+Gb/s ICs and atomic-scale semiconductor device technologies. His lecture will cover the main features of FD-SOI CMOS technology and how to efficiently use its unique features and suitable circuit topologies for mm-wave and broadband SoCs. He'll begin with an overview of the impact of the back-gate bias and temperature on the measured I-V, transconductance, fT, and fMAX characteristics. Then he'll compare the maximum available gain, MAG, of FDSOI MOSFETs with those of planar bulk CMOS and SiGe BiCMOS transistors through measurements up to 325 GHz. Next, he'll provide biasing, sizing and step-by-step design examples for VCO, doubler, switches, PA, large swing optical modulator drivers and quasi-CML circuit topologies and layouts that make efficient use of the back-gate bias to overcome the limitations associated with the low breakdown voltage of 20nm and 12nm FD-SOI CMOS technologies. Sign Up Now!With over 100 attendees filling every chair in the auditorium, last year's training day was sold out. Although it was in Silicon Valley, people actually flew in from all over the world to be there. During the Q A at the end, most everyone prefaced their questions by saying, “Thank you. I really learned a lot today.” 2018 will be no different – except that it's sure to sell out even faster. Please note, though, that this is not a free event, so only the attendees will get copies of the slide decks. Here's key info you need to sign up. See you there!What: SOI Consortium's FD-SOI Training DayWhen: 27 April 2018, 7:30am – 5pm.Where: Crowne Plaza San Jose, Milpitas CA (parking is free)Registration fee: US $485.00 (includes training book, breakfast, box lunch and refreshments during breaks)How to sign up: Click here to go directly to the registration site.

They're calling it, “The most advanced, lowest power-consuming GPU-enabled MPU on the market.” It's NXP's new i.MX 7ULP general-purpose processor, and it's on 28nm FD-SOI. They've got a nifty video summing it all up – you can watch it here. [caption id="attachment_10388" align="alignleft" width="300"] NXP is first to market with a general-purpose processor on FD-SOI: the i.MX 7ULP. It's got both ultra-low power consumption and rich graphics for battery powered applications. (Courtesy: NXP)[/caption] With the i.MX 7ULP, NXP is first to market with an FD-SOI applications processor offering the industry’s lowest power consumption. The debut was made at the recent Embedded World Conference in Nuremberg, Germany, and it made a big splash in media across the globe. (Read the full press release here.) In deep sleep mode, it boasts power consumption of just 15 uW or less: 17 times less than previous (and highly successful) low power i.MX 7 devices. Dynamic power efficiency is improved by 50 percent on the real-time domain.The i.MX 7ULP applications processor family is currently sampling to select customers. Broader availability of pre-production samples is scheduled for Q3 2017.Hello, IoT!The high-performance, low-power solution is optimized for customers developing applications that spend a significant amount of time in standby mode with short bursts of performance-intense activity that require exceptional graphics processing. Sounds like IoT – and indeed it is, and more.With the i.MX 7ULP, NXP's targeting wearables, portable healthcare, smart home controls, gaming accessories, building automation, general embedded control and IoT edge solutions. Bottom line: it's designed to enable ultra-low-power and secure, portable applications – especially those demanding long battery life. (Read the current fact sheet here.)The detailsThe i.MX 7ULP features an advanced implementation of the ARM® Cortex®-A7 core, the ARM Cortex-M4 core, as well as a 3D and 2D Graphic Processing Units (GPUs). It's got a 32-bit LPDDR2/LPDDR3 memory interface and a number of other interfaces for connecting peripherals, such as WLAN, Bluetooth, GPS, displays, and camera sensors. [caption id="attachment_10387" align="alignnone" width="834"] (Courtesy: NXP)[/caption] NXP says this new design, based on FD-SOI’s lower voltage capability, enables rich user experience through extremely power-efficient graphics acceleration, a fundamental requirement in many of today’s consumer and industrial battery-operated devices that incorporate robust graphic interfaces. Further enablement includes rich Linux or Android ecosystem with the real-time capability supported by FreeRTOS.Leveraging body biasing and moreNXP credits the design’s extreme low leakage and operating voltage (Vdd) scalability to that FD-SOI specialty: reverse and forward body biasing (RBB/FBB) of the transistors, and its smart power system architecture.In presenting the new i.MX 7ULP to the tech press, the company highlighted the following FD-SOI design advantages: Large dynamic gate and body biasing voltage range Domain and subsystem optimization with custom standard cell library with mixed voltages Low quiescent current (Iq) bias generators Enhanced ADC performance with unique FD-SOI attributes Fail Safe I/O for simplified low power system design To that, add a note about security. As the chip's fact sheet says, “The processors deliver hardware-enabled security features that enable secure e-commerce, digital rights management (DRM), information encryption secure boot, and tamper detection.” Those are just the sort of things that demand the bursts of high performance that dynamic forward body biasing delivers where and when it's needed.Samsung fabs, Verisilicon adds IPTwo other SOI Consortium members – Samsung and Verisilicon – are particularly pleased with NXP's results.“We are excited that NXP is the first to bring the benefits of FD-SOI (28FDS) technology to the general purpose market,” says Ryan Lee, VP of the Foundry Marketing Team at Samsung Electronics. “28FDS technology will satisfy a growing and critical need for ultra low power designs that require power-performance at very low voltages. We plan to evolve 28FDS technology to a differentiated low-power single platform by implementing RF and embedded Non-Volatile Memory (eNVM) solution for our customers’ success.”NXP’s processor design enables robust low power graphics for the IoT and wearable markets through two graphic processor units (GPU) from Vivante: the GC7000 NanoUltra 3D GPU with a low power single shader, and the GC320 Composition Processing Core (CPC) for 2D graphics. The 3D GPU plays a critical role in enabling rich 3D based user interfaces, while the CPC can accelerate both rich 3D and simpler 2D user interfaces. Processors based on the combination of the two GPUs enable efficient display systems which offload and significantly reduce system resources, in turn providing rich user interfaces at low power levels to extend the battery life of devices.“Our 3D GPU is a result of a joint collaboration between Vivante and NXP to deliver industry-leading 3D capabilities with the lowest power consumption,” said Wei-Jin Dai CEO at Vivante Corporation and Chief Strategy Officer and GM of the IP Division at Verisilicon. “The power savings from using the right GPU in an ultra low power processor is one of the major attributes and advantages of the architecture.”So, now shall we dig in a little deeper into the “why FD-SOI” question? Read on in Part 2 of this article.-- By Adele Hars, ASN Editor-in-Chief