Interview: Targeting all Power Applications from PCs to Industrial Equipment


Satya Dixit, Senior Director, Systems and Applications Engineering at Rohm Semiconductor

Satya Dixit

Rohm was founded in 1958 and renamed in Rohm Semiconductor in 2009. How would you describe the company's status in the electronics industry today?

You have notice it, Henning. It started the journey as a Resistor company and it was producing Discrete Semiconductor initially. From there, Rohm has come a long way and the currently only 37% of the revenue comes from Discrete Semiconductor and over 46% from Integrated Circuits.

Rohm Semiconductor has become a major player in multiple verticals, like, Consumer and smart devices, Industrial and IoT, and Automotive. The recent acquisition of Powervation, a Digital Power Controller company, broadens our portfolio in power electronics. 

As one of the most respected semiconductor companies in Japan and top supplier of semiconductors in some categories of power electronics in the world, Rohm is increasing its footprint in the Sensors and Power Electronics for the Industrial, Smart Devices, Automotive segments.

As per the IHS report on Semiconductor Ranking, Rohm ranks #25 in total semiconductors, #8 in the discrete segment and #2 in the small signals device segment in the world.

How does power electronics rank within your company?

Satya Dixit: Power Electronics, including power management ICs, is the major segment of the company, addressing very low quiescent current devices for wearables and smart phones to mid power solutions for PCs, servers and high power for industrial and automotive segments. Synthetically providing by combining ICs and discretes as solutions is one of our company’s advantages.

Figure 1: Product segments of Rohm Semiconductor

Which regions in the global market are of special interest to you?

We divided our sales ratio into four markets: Japan, Asia (including China), US, and Europe. In Europe, the automotive and industry markets account for around 80% of the semiconductor demand, perfectly matching our mid-term strategy. Looking ahead, Europe will grow increasingly important to us, so we will further focus our efforts there. The US is important because they are constantly creating new technologies and solutions. This creative edge makes America a great place for R&D. Furthermore, we all know the automotive capability of America, both in terms of innovation and production, which further enhances our interest. In Asia, we are targeting our efforts on China. With its rising middle class, China is showing an increased demand for smartphones and sophisticated consumer electronics, markets that are important to us.

Your product portfolio runs from MOSFETs and IGBTs to SiC components and Intelligent Power Modules. Are you targeting every power application?

Rohm is targeting all power applications from PCs to industrial equipment. We supply Si for up to 600V applications and SiC for up to 1700V. To expand the adaptable applications, we continue to develop higher power devices in the future.  

Which products did you introduce during the PCIM 2017? Briefly, what are their highlights?

We are getting recognized as a leading company of SiC, then this PCIM we showed gated driver for SiC drives and new products of Silicon IGBT to appeal to total Power Device Solution Companies. And application examples were shown like Zaptec charger for Electric vehicles and customer modules in Europe. 

Rohm is able to offer customers not only a full line-up of efficient and compact products for their applications, but also a complete solution for the power channel. We showed power semiconductor solutions with five categories as ‘SiC', ‘Power IC', ‘Automotive', 'Industrial' and ‘Motor Drive'. 

Our new series of Isolated Gate Driver ICs for power MOSFETs expands the existing portfolio and improves the design of industrial and automotive power systems. 

The first released product of this series is a gate driver device. It has an output current of 4A, a built-in active miller clamping to prevent parasitic turn on effects and integrates an under-voltage lock-out (UVLO) optimized to drive our SiC MOSFETs. The optimized UVLO improves the reliability of the system – a very sensitive topic in Automotive and Industrial applications. 

Moreover, the new 1200V/400A and 600A full SiC power modules include latest SiC SBDs and MOSFETs with a new low inductance structure. The provided function allows reducing the thermal resistance value between module-case and heatsink which enables a smaller size of the cooling system. These properties make them ideal replacements for 400, 600A and even 1000A Si IGBT-based Power Modules, depending on the customers' switching frequency. 
We also showed our new 650V IGBTs which are overcoming the trade-off between saturation voltage and turn-off loss characteristics. Measurement results show low noise performance while keeping a higher switching speed.

Figure 2: Switching Loss Comparison SiCs vs IGBTs. Rohm has developed 1200V 400A/600A rated full SiC power modules (BSM400D12P3G002/ BSM600D12P3G001) optimized for inverters and converters in solar power conditioners, UPS, and power supplies for industrial equipment.

Regarding power products: What trends do you see in the market for electric and hybrid electric vehicles?

I see HEV/EV related applications (Inverter, DC/DC converter, On-board charger) ISO26262 compliant devices, primary Boost, Buck-boost products for Start-stop design, and ADAS related applications. Furthermore:

  • Radar, Camera module and Control board ECU with PMIC and discrete regulator solutions,
  • SoC PMIC solution activities aiming at future autonomous driving in 2025.

Which materials are the foundation for power electronics today and maybe in three to five years from now?

There are few technologies that are suited to handle new requirements: Silicon IGBT, Super Junction MOSFETs, GaN and SiC devices.  However, SiC remains hot, as more resources are put on this by many companies and it is advancing and maturing faster for the HEV/EV and Industrial markets. GaN has still not gained enough traction and this will still be the target for many companies and applications. Wide Band Gap materials will continue to thrive in the power electronics industry.

Which role plays your subsidiary SiCrystal AG?

SiCrystal produces SiC wafers from crystal growth, external polishing, flat formation, slicing, sanding, edge polishing and cleaning and supplies to the Rohm factories where photo masking, chip design, wafer process and assembly is done. This is the main source of SiC wafers for our SiC devices that are designed and manufactured.

How are your customers adapting the SiC MOSFET/IGBT Discrete Evaluation Board and other design aids?

Rohm delivers SiC MOSFET/IGBT Discrete Evaluation Boards for customers to evaluate in their designs. In some cases, we also make the reference designs that are closer to customer applications and hence making it easy for customer to evaluate our devices in their application. We also provide the device characterization data, circuit simulations, schematics, layout guidelines and external component selection. This helps the customer to adapt our solutions easily into their designs.

What kind of feedback are you getting from your Tech Web? Any major technical or communication trends?

Rohm receives requests for simulation models for our industrial solutions, self-help documents and material with all the technical answers are some of the trends that we have seen.

In recent years, the number of electronics engineers, who look for many kinds of information online, is increasing. Rohm picks up technology focusing contents from basic to advance in our own media TechWeb. For example, the design and evaluation method of power management and power devices such as Si and SiC. 
Many engineers use this site to gain knowledge of power management and to get the latest product or technology information. This site is supported by our engineers, who have the deep knowledge of both analog and power products. It will increase the Rohm’s brand awareness, the number of fans for our company and leads to a steady business in the future.

Regarding power electronics - what can our readers expect from Rohm Semiconductor in the near future?

Satya Dixit: Rohm continues to develop and deliver solutions in Industrial and Automotive segments. Digital Power is another area the readers can expect solutions for datacenter and high power applications. Most of the solutions we have in SiC are the most reliable ones compared to any solutions out there.  SiC, IGBT, DigiBuck, PMICs and very low quiescent current devices are the focus of our power electronics products coming in the future.

Mr. Dixit, thank you for this interview!

In 1958 Rohm was established in Kyoto, Japan, as a manufacturer of small electronic components. In 1967 the production was expanded to include transistors and diodes, followed in 1969 by ICs and other semiconductor products. Two years later Rohm established a sales office and an IC design center in the Silicon Valley - the first step into the worldwide semiconductor market.

Satya Dixit is the Senior Director, Systems and Applications Engineering at ROHM Semiconductor. His team defines and develops new products, customer solutions, and system architectures. They also perform IC validation and help introduce new products. Satya addresses the needs of multiple markets, including mobile, consumer, PC, automotive, and industrial segments.

Interview conducted by Henning Wriedt, US-Correspondent Bodo's Power Systems


 

Source: Bodo's Power Systems, September 2017