[Editor's Note] Existing relay and fuse systems are reaching their limits due to the rapid increase in automobile power demand. In particular, efficient power distribution and space/weight optimization are essential for electric vehicles. In this context, STMicroelectronics' STi2Fuse provides real-time load monitoring and control and wire diameter optimization based on I2T blocking curves, enabling immediate protection and automatic recovery in the event of a failure. It is approximately 25% lighter and smaller than existing products, saving vehicle space and optimizing power distribution architecture while maximizing ease of maintenance and system performance. Accordingly, our magazine arranged a meeting with ST Vice President Choi Young-min to learn more about STi2Fuse.


■ Introduction to ST's automotive power distribution solution STi2Fuse and why it is attracting attention

STi2Fuse is a solution for automotive power distribution that provides the ability to monitor and control the load status of each output channel in real time.

It provides protection and automatic recovery in the event of a failure, and has the same I2t algorithm as the existing melting fuse, so it can be blocked by the I2t blocking curve set by the user.

This optimizes the vehicle's wiring, reducing wire weight by approximately 20%, and enables circuit design that is approximately 25% lighter and smaller than existing relay fuse configurations, contributing to improved vehicle fuel efficiency.

These features make STi2Fuse products a suitable solution for Zonal Architecture.

■ What solution (or product) are you introducing?

The STi2Fuse product line introduced today consists of monolithic, hybrid, and controller types, and can be reviewed to meet various load current requirements.

The monolithic product is designed for zonal boxes for small currents, the hybrid product is designed for power distribution boxes for medium currents, and the controller type is designed for main switches of power sources for large currents.

There is also a companion product that supports the active standby function. We plan to introduce them together.

■ Main application applications are

STi2Fuse can be used as a switch and fuse for vehicle power distribution and power supply to various ECUs (Electronic Control Units).

■ Key requirements of the market/industry

It must provide stable power supply under various load conditions, and especially in situations such as hard short, it must be quickly shut off within 100us to maintain the power line stability.

In addition to the I2t algorithm, which is identical to the existing fuse-cutting algorithm for wire protection, a fail-safe mode is required to ensure that each channel can operate normally even when communication with the MCU is not possible.

Additionally, like a normal fuse, an active standby function is required that must always be turned on with low operating current in standby mode.

■ The main benefits are

The biggest advantage of STi2Fuse is that it can automatically protect wires in overcurrent situations without MCU intervention through a user-configurable I2t algorithm.

This allows the wire to be optimized for the load current.

It also quickly cuts off power even in hard short situations to keep the power line stable, and normal operation of the device is possible even in micro-cut situations of the battery.

In addition, the CCM (Current Control Mode) function can effectively limit the inrush current of large-capacity capacitor loads, and the status diagnosis function can monitor the chip temperature and the voltage and current of the output channel in real time to predict risks in advance.>
■ What are the differences compared to existing products?

I will explain it broadly in three ways.

First, in the I2t wire protection function setting, the normal current and time can be set in 8 steps each via SPI communication, allowing a total of 64 combinations.

This is very effective for wire optimization as it can be set in much more detail than third-party products.

Second, for monolithic products, it supports a parallel mode function that can double the driving current by connecting output channels in parallel.

This allows for flexible response to various current requirements.

Lastly, we offer single, dual, and quad channel products depending on the product, and we offer a wide range of products from low current of 1.5A to high current of 450A.

This diversity and flexibility makes STi2Fuse a strong competitor in the market.

■ Please say a word to e4ds readers regarding the content introduced today.

Thank you for your interest and participation in the STi2Fuse family of products.

We ask for your continued interest in ST’s diverse products and technologies.

thank you