InterviewFeatured in ELEKTRONIK PRAXIS
Dec 13th, 2024
ROHM’s Analog Semiconductor Strategy
*The content and speaker titles are accurate as of the time of the interview (December 2024)
ROHM is strengthening its efforts in the field of analog semiconductors. The key to success lies in developing best-in-class analog ICs. But how can such products be created? To gain insight into the technical and product strategies for achieving this, we spoke with Sumihiro Takashima, Director of ROHM’s LSI Business Unit.
――― What is the key to ROHM's success in the field of analog technology?
――― What single-function ICs does ROHM currently offer?
Takashima:
One example is our op amps designed to amplify sensor signals. These op amp ICs feature outstanding noise characteristics, reaching the highest standards in the industry and rivaling those of European and American manufacturers. How did we manage to catch up to Western competitors? By thoroughly refining in-house technologies, including manufacturing processes, layout, and circuit design. Going forward, we aim to capture market share in the op amp IC segment from our Western competitors.
We are also increasing our focus on AD/DA converter ICs. Until now, we had not commercialized single-function AD/DA converter ICs. However, we have recently released 14bit AD converters to the market while also completing the technical development of 16bit AD converters. In the future, we plan to expand our portfolio to include up to 20bit successive approximation (SAR) types and up to 24bit ΔΣ models.
――― This may seem like a simple question, but is it easy to develop single-function ICs?
Takashima:
Initially, our company specialized in designing and developing custom SoCs for major home appliance manufacturers, which included built-in functions like op amps and AD converters. By extracting these functions, it is possible to create single-function ICs. However, even if we produce single-function ICs in this way, it is difficult to claim they are fully ready for commercial use. In other words, simply extracting the functions is not sufficient.
This is the most challenging part of development. Creating products in isolation won't lead to sales. What kind of performance is required, and what level of usability is necessary? To find out, we conducted a thorough investigation of single-function ICs from competing manufacturers. Based on the results, we decided to first commercialize the most popular single-function ICs, then expand the lineup horizontally from there. Given our limited resources, it is crucial to prioritize the order of development and proceed with commercialization accordingly.
――― Are there any best-in-class products among the single-function ICs that ROHM currently offers?
Takashima:
The EMARMOUR™ series of op amps, known for low noise and strong resistance to external noise, can be considered best-in-class. These op amps deliver industry-leading noise performance. One aspect is low-noise characteristics, meaning they generate almost no noise. The other feature is high EMI tolerance, making them less susceptible to external noise. In recent years, applications such as industrial equipment and automotive systems have become increasingly electronic while also requiring greater miniaturization and higher density. This has led to extremely harsh electromagnetic and noise environments. Using an op amp IC highly resistant to noise simplifies design by eliminating noise concerns. Our op amp ICs maintain a stable output signal with minimal fluctuation, even when exposed to noise across all frequency bands.
These op amp ICs are made possible by improving and integrating various technologies, including circuit design, layout and manufacturing processes. ROHM is developing and providing these valuable products.
―――What other analog ICs are you focusing on?
Takashima:
Focusing on developing analog ICs that work with power semiconductors is our priority. For example, gate driver ICs and power control ICs for GaN power devices are being developed. GaN power semiconductors are currently used in the miniaturization and high functionality of AC adapters and USB chargers.
To promote the adoption of GaN semiconductors, it is essential to provide the power circuit topology as well. GaN power semiconductors offer excellent performance but are very difficult to use and challenging to fully optimize. Therefore, it’s crucial to supply the entire power circuit design, including GaN power semiconductors and peripheral components, to enhance usability. Power supply control ICs and gate driver ICs are particularly critical. For this reason, it is quite difficult for semiconductor manufacturers that only handle GaN power semiconductors to enter the market.
One approach is through modularization. We offer modules that combine GaN power semiconductors with gate driver ICs, power supply control ICs, and inductors. This makes it easy to leverage the primary advantage of GaN semiconductors, namely high-speed operation.
Are specialized products required for power control and gate driver ICs?
Takashima:
Yes, specialized power supply and gate driver ICs are essential to fully exploit the high-speed characteristics of GaN power semiconductors.
To achieve high-speed switching operation, it is necessary to generate pulse signals with extremely narrow time widths on the order of nanoseconds. Our technology that accomplishes this is called Nano Pulse Control™. Combining this with GaN power semiconductors enables ultra-high-speed switching. We are currently preparing to offer a solution that integrates a power control IC utilizing Nano Pulse technology together with a GaN power semiconductor in a single package.
―――What applications benefit from the high-speed performance of GaN power semiconductors?
Takashima:
Sets that handle more power than AC adapters and USB chargers, such as DC-DC converters used in cloud servers and wireless base stations. For example, applications that step down 48V input to 2.5V are ideal candidates. By applying GaN power semiconductors, greater miniaturization through high-frequency operation can be achieved, along with increased efficiency. ROHM will continue to develop valuable products like these in the future.
EMARMOUR™ and Nano Pulse Control™ are trademarks or registered trademarks of ROHM Co., Ltd.
Takashima:
It is necessary to offer a range of single-function ICs such as op amps and AD/DA converters. This is especially important for products targeting long-tail markets like industrial equipment, where a diverse lineup of single-function products is essential.
However, until now, our company has not prioritized single-function ICs. Consequently, we have not invested much effort into developing our sales channels. As a result, our single-function ICs are rarely displayed as options on the sales websites of online retailers. Going forward, as we shift our focus on expanding into the industrial equipment market, it is necessary to strengthen our lineup of single-function ICs. We are currently laying the groundwork for this expansion.
It will likely take time before these efforts yield significant results. However, I firmly believe we need to act now. Although it hasn't been long since we began, we’re already starting to see the first signs of progress.