everything PE recently interviewed Takahisa Shikama, Semiconductor Strategy and Business Leader at Asahi Kasei Microdevices. Asahi Kasei Microdevices designs and manufactures advanced sensing devices and high-end integrated circuit (IC) products.

Q. Can you give us a brief history of Asahi Kasei? When was the company founded? What was the objective?

Takahisa Shikama: Asahi Kasei Microdevices (AKM) is part of the Asahi Kasei Group, whose origins date back to 1922. The company was founded with the objective of improving people’s standard of living by supplying high-quality daily necessities in abundant quantities at affordable prices. Over the decades, the Asahi Kasei Group has continuously expanded and diversified its business portfolio in response to evolving societal needs, growing into a global company with operations spanning materials, homes, healthcare, and electronics. 

Asahi Kasei Microdevices operates an electronic components business as a member of the Asahi Kasei Group's material sector. AKM provides customers with unique products by combining the compound semiconductor technology mainly used for magnetic sensors with the ASIC/analog circuit technology based on silicon semiconductors. Our products and solutions with these features are expanded over a wide range of fields, including mobile communication devices and consumer products as well as automotive electronics devices, household equipment, and industrial equipment.

Q. How are software-defined vehicles and intelligent industrial systems influencing the evolution of sensing and power semiconductor technologies?

Takahisa Shikama: Software-defined vehicles and intelligent industrial systems are changing the role of power electronics from simple energy conversion blocks into highly connected, highly optimized control platforms.

In the past, many power systems were designed mainly around hardware efficiency and robustness. Today, software increasingly optimizes motor control, energy management, predictive diagnostics, and system safety in real time. This means that the quality of sensing data becomes much more important. Accurate, fast, and reliable current and voltage information is essential for the control algorithm to make the right decision.

At the same time, power semiconductor technologies such as SiC and GaN are enabling higher switching frequencies, higher power density, and higher system efficiency. However, these benefits can only be fully realized when sensing technologies can keep up with faster transient behavior, higher EMI levels, and stricter safety requirements.

Therefore, the evolution of power semiconductors and sensing technologies are strongly linked. Advanced sensing is no longer just a protection component; it is becoming an enabler of software-defined power control, higher efficiency, functional safety, and system-level miniaturization.

Q. How are Asahi Kasei’s magnetic sensing technologies helping improve efficiency, precision, and reliability in next-generation power conversion systems?

Takahisa Shikama: Asahi Kasei Microdevices brings together decades of expertise across three core domains: compound Hall element technology, high-precision analog signal processing, and advanced packaging; and our current sensors are built on this integrated foundation.

In next-generation power conversion systems, accurate current feedback is fundamental: it enables precise motor control, reduced torque ripple, optimized switching, and robust system protection. Fast response is equally critical, particularly for overcurrent detection in SiC- and GaN-based designs where switching speeds continue to push boundaries.

Our magnetic sensing technologies address these demands through compact, isolated, high-speed current sensing solutions. Coreless architectures, in particular, eliminate bulky magnetic cores without sacrificing accuracy or response time — directly contributing to system miniaturization.

Beyond the sensor IC itself, the real value we deliver lies in simplifying current sensing structures, increasing design flexibility, and improving long-term reliability across demanding automotive and industrial environments.

Q. How is the transition toward silicon carbide (SiC) and gallium nitride (GaN) power devices changing sensing and control requirements in power electronics?

Takahisa Shikama: SiC and GaN devices are changing the speed of power electronics. They enable faster switching, lower losses, and higher power density compared with conventional silicon IGBTs or MOSFETs. However, this also creates new challenges for sensing and control. 

First, the current sensor must have sufficient bandwidth and response speed to capture fast current changes. If the sensor response is too slow, the control system may not accurately detect transient events or overcurrent conditions.

Second, EMI becomes much more severe. Fast dv/dt and di/dt can introduce noise into the sensing path, so the sensor IC, package, PCB layout, and signal interface must be carefully designed.

Third, accuracy remains important even under harsh electrical conditions. In traction inverters, industrial servo drives, and high-power converters, even small sensing errors can affect control performance, thermal margin, and system reliability.

As a result, the transition to SiC and GaN is increasing the demand for current sensing technologies that combine high accuracy, fast response, robust isolation, and strong noise immunity.

Q. What factors are currently driving interest in coreless current sensing technologies for EV applications?

Takahisa Shikama: There are several factors driving interest in coreless current sensing for EV applications. The first is downsizing. EV traction inverters, onboard chargers, DC-DC converters, and other power electronics systems are under continuous pressure to become smaller and lighter. Magnetic cores can be relatively bulky, so removing the core can help improve layout flexibility and reduce system volume.

CZ3K series current sensors

The second is high-speed response. As SiC and GaN devices become more common, fast current detection becomes more important. Coreless sensing can be suitable for high-speed current measurement and fast overcurrent detection. The third is design flexibility. Coreless current sensors can support more compact and flexible mechanical structures compared with conventional core-based approaches.

The fourth is reliability and manufacturability. Removing the magnetic core can reduce some mechanical and magnetic design constraints, such as core saturation and assembly complexity.

In EV applications, the value of coreless sensing is therefore not only component-level performance, but also system-level benefits such as compactness, fast protection, and easier integration.

Q. Could you explain the operating principles behind Asahi Kasei’s coreless current sensing technology and the advantages it offers compared with conventional magnetic-core-based sensing approaches?

Takahisa Shikama: In a coreless current sensor, the current flowing through the primary conductor generates a magnetic field around the conductor. Asahi Kasei Microdevices’s magnetic sensing element detects this magnetic field directly, without using a magnetic core to concentrate the flux.

The detected magnetic field is then converted into an electrical signal by the sensor IC and processed through analog signal conditioning. Because the sensing principle is based on magnetic field detection, galvanic isolation can be achieved between the primary current path and the signal output side.

Compared with conventional magnetic-core-based current sensing, the coreless approach offers several advantages. First, it can reduce size and weight because it does not require a bulky magnetic core. Second, it avoids issues related to core saturation, which can be important in high-current or transient conditions.

Third, it can support fast response, which is useful for protection and high-speed control. Fourth, it can provide more design flexibility for compact power electronics modules.

Of course, coreless sensing also requires strong magnetic sensing capability and careful IC and package design, because the sensor must accurately detect the magnetic field without the help of a core. This is where our experience in magnetic sensing and analog IC design becomes important.

Q. As EV platforms move toward higher voltages and faster switching frequencies, how important is high-precision current sensing for traction inverter performance?

Takahisa Shikama: High-precision current sensing is becoming increasingly important for traction inverter performance. In an EV traction inverter, the motor current is directly related to torque generation. Therefore, current sensing accuracy affects torque control, motor efficiency, noise and vibration, and driving feel. High-precision current feedback allows the control system to optimize motor operation over a wide speed and load range.

As EV platforms move to higher voltages, such as 800 V architectures and adopt faster-switching power devices, the electrical environment becomes more demanding. The sensor must maintain accuracy even under high dv/dt, high common-mode noise, and rapid current transients.

Precision is also important for system protection and thermal design. If current measurement has large errors, the system may need larger design margins, which can reduce power density or increase cost. More accurate sensing allows engineers to design closer to the optimal operating point while maintaining safety.

Therefore, current sensing is not a secondary component. It is one of the key technologies that enables high-performance, efficient, and reliable traction inverter design.

Q. What are the key EMI and signal integrity challenges associated with sensing in high-speed power electronics environments?

Takahisa Shikama: In high-speed power electronics, EMI and signal integrity are among the most critical challenges for current sensing. Fast-switching SiC and GaN devices generate high dv/dt and di/dt. These fast transitions can couple noise into the sensing signal through parasitic capacitance, magnetic coupling, ground bounce, and PCB layout paths. As a result, the sensor output may contain noise, offset shift, or transient disturbance if the system is not properly designed.

Another challenge is maintaining signal accuracy while preserving fast response. Filtering can reduce noise, but excessive filtering can slow down the response time. Therefore, the sensor and system designer must find the right balance between noise immunity and bandwidth. Isolation performance is also important. In high-voltage systems, the sensor must provide reliable galvanic isolation while minimizing common-mode noise coupling.

To address these challenges, it is important to consider the complete signal chain: the sensing element, IC design, package structure, isolation design, PCB layout, grounding, shielding, and the digital or analog interface. In high-speed power electronics, current sensing performance is ultimately determined by both the sensor device and the system implementation.

Q. Beyond traction inverters, which automotive or industrial applications does Asahi Kasei see as major future growth areas for advanced current sensing technologies?

Takahisa Shikama: Beyond traction inverters, we see several important growth areas for advanced current sensing technologies. In automotive applications, onboard chargers, DC-DC converters, electric compressors, electric pumps, and battery-related systems are important areas. As vehicles become more electrified, the number of power conversion blocks inside the vehicle continues to increase.

We also see opportunities in charging infrastructure, especially as higher-power and higher-efficiency charging systems are developed. Accurate and reliable current sensing is important for power control, protection, and energy management.

Another interesting direction is intelligent power systems. As industrial equipment becomes more connected and software-defined, current sensing can also support condition monitoring, predictive maintenance, and system diagnostics.

Therefore, our view is that advanced current sensing will expand from conventional control and protection into a broader role as a key data source for intelligent power electronics.

Q. Looking ahead, what are Asahi Kasei’s key technology priorities for 2026? Are there any upcoming product developments?

Takahisa Shikama: Looking ahead to 2026, our key technology priorities are aligned with the major trends in power electronics: higher efficiency, higher power density, faster switching, and more intelligent system control.

For current sensing, we will continue to focus on high accuracy, fast response, compact size, robust isolation, and strong EMI immunity. These are especially important for EV traction inverters, onboard chargers, industrial drives, and next-generation power conversion systems using SiC and GaN devices.

Another important priority is system-level value. Customers are not only looking for a sensor IC; they are looking for solutions that help reduce inverter size, simplify design, improve protection, and support better control performance. Therefore, we will continue to strengthen our ability to provide application-oriented solutions, including reference designs, technical support, and collaboration with customers.

Regarding product development, we are continuing to expand our current sensing portfolio to address the needs of high-voltage, high-speed, and compact power electronics applications. While we cannot disclose all roadmap details at this stage, our direction is clear: we aim to provide advanced magnetic sensing solutions that help customers build smaller, more efficient, and more reliable power conversion systems.

About Takahisa Shikama

Takahisa Shikama received his master’s degree in materials science from the University of Tokyo. Since joining Asahi Kasei Microdevices in 2012, he has contributed to the development of magnetic and infrared sensor technologies and has generated several patented inventions. With experience spanning engineering, customer support, and business development, including five years in Germany supporting European customers, he now focuses on business development and product management for current sensor solutions.