[Editor's Note] Recently, the e4ds Electrical and Electronic Lifelong Education Center held the '2025 Advanced Engineer Practical Master Class' as an offline course. Targeting current developers who have completed the intermediate course and engineers with practical experience in circuit design, this course covers advanced topics in electronic circuit design and real-world problems in precision measurement environments. Accordingly, we interviewed Professor Cho Seong-jae of the Department of Electrical and Electronic Engineering at Shinhan University, who is teaching this course, to learn about the course's direction and engineering education. This interview will be published in a six-part series.


The real danger in circuit design lies in the 'OFF' moment.

When does the greatest risk occur in electronic circuit design? Many engineers think of the moment a circuit is operating, but the point at which components actually fail is not 'during operation,' but 'the moment operation stops.'

Professor Cho Seong-jae, who worked at Samsung Electronics for 10 years and at Shinhan University for 32 years and is currently an emeritus professor, emphasized that one must learn through experience what risks arise at unexpected moments during the actual electronic design process.

Professor Cho Seong-jae emphasized, “Transistors pose no problem when turned on, but unexpected back EMF and transient phenomena can occur the moment they switch to OFF, potentially damaging the components,” adding, “This aspect is rarely covered in textbooks.”

Professor Cho Seong-jae is focusing intensively on these practical issues in the currently ongoing intermediate and advanced circuit design training courses.

He said, “You cannot solve problems that occur in actual industrial settings by merely learning how circuits operate normally,” adding, “You must see and understand firsthand why components break and under what conditions risks arise.”

A typical example is the back electromotive force generated in a circuit containing an inductor.

When the TR is suddenly switched from the ON state to OFF, the energy stored in the coil instantaneously generates a high voltage.

Professor Cho Seong-jae explained, “As seen in the formula V = L × di/dt, the voltage increases exponentially as the time of current change (dt) shortens,” adding, “This transient voltage is the main cause of TR damage.”

Professor Cho Seong-jae also covers protection circuit design methods to solve these problems in the curriculum.

intermediate and advanced courses The difference is also clear.

The intermediate course is structured around problems occurring in general circuits and their solutions.

On the other hand, the advanced course covers highly advanced technologies for specialized applications, such as the design of IV converters handling microcurrents in the nanoampere (nA) or picoampere (pA) range.

Professor Cho Seong-jae said, “As LiDAR and optical sensor-based systems become more prevalent, the importance of ultra-fine current measurement technology is growing,” adding, “Since this field is difficult to approach without practical experience, it is covered intensively in the advanced course.”

Another key topic is 'measuring instrument reliability'.

While many engineers accept measurements from oscilloscopes or multimeters as absolute standards, Professor Cho warns, “Measurement instruments affect the circuit during the measurement process,” adding that “blindly trusting instruments can actually lead to incorrect judgments.”

In fact, parasitic components generated when measuring on a breadboard and the load effect of oscilloscope probes are typical examples of how circuit operation is distorted.

Professor Cho Seong-jae defines the goal of this training as “the ability to design stable circuits.”

The key is to possess the ability to design circuits that not only operate but also prevent damage, minimize malfunctions, and operate reliably even in special environments.

While noise is also an important topic, this course focuses on damage prevention, and noise analysis will be covered in a separate advanced course.

Finally, regarding the conditions for an engineer's growth, he emphasized, "Ultimately, one's own understanding and passion are the most important."

“Skills do not improve automatically just by attending lectures. You must realize things for yourself through the process of experimenting, failing, finding the causes, and redesigning. You can only grow when you make an effort to perfectly understand why every component of a circuit exists and what role it plays,” he stated.

Professor Cho Seong-jae's educational philosophy is clear.

Creating engineers who can solve problems encountered in the field

The practice-oriented approach he emphasizes offers a new direction to many engineers seeking to bridge the gap between theory and reality.