Inverter Configurations and Analog Devices Product Lineup

Analog Devices, which has a rich track record in automotive semiconductors, offers a comprehensive lineup of high-performance products that meet the needs of EV developers.

This time we will introduce inverter solutions, but there are a variety of other solutions for EV powertrains such as on-board chargers (OBCs), battery management systems (BMS), and DC/DC converters. Provided.

Key devices that make up an inverter include isolated gate drivers, isolated power supplies, isolated amplifiers, and digital isolators. Analog Devices has multiple solutions for each, allowing you to select the most suitable device for your system.

Among them, we will pick up and introduce the most recommended solutions this time.

iCoupler🄬 technology that increases the safety and reliability of inverters

Analog Devices' unique digital isolation technology "iCoupler🄬 Technology" contributes to improving inverter performance. Overcomes the problems of conventional photocouplers by using a magnetic insulation method that uses polyimide insulators. It achieves improved insulation reliability, faster transmission rates, lower power consumption, and smaller circuits.

Insulated gate drivers that influence drive performance of inverters

Among the devices used in inverters, the isolated gate driver is an important device that affects drive performance, along with the power switch.

Analog Devices' isolated gate drivers utilize iCoupler🄬 technology to provide ultra-low propagation delay without sacrificing common mode transient immunity (CMTI). It is compatible not only with silicon-based IGBTs and MOSFETs, but also with SiC and GaN based on wide band gap materials, so combining them will contribute to higher efficiency and smaller size.

One example is the ADuM4177, a 30A compatible SiC gate driver. It achieves an on-resistance of less than 0.4Ω and provides the industry's highest class drive capability.

It is fully equipped with protection and self-diagnosis functions such as DESAT, soft shutdown, Miller clamp, voltage monitoring, and fault reporting, and is also functional safety (Fusa) compatible. It has programmable registers in EEPROM and can be accessed via SPI. Additionally, slew rate selection is possible via SPI.

​The ADuM4177 is Analog Devices' highest performance isolated gate driver.

Also, for those who want to master a simple product, "ADuM4135" cannot be overlooked. Basic functions such as DESAT detection, Miller clamp, and soft shutdown are provided, and sufficient performance is achieved with 100kV /µs​ ​CMTI and 55ns propagation delay characteristics.

Since there are multiple other products, it is possible to select according to the specifications and configuration of the system.

Isolated power supply (flyback controller) that contributes to miniaturization

Next, we will introduce Analog Devices' isolated power supply (flyback controller) that contributes to miniaturization.

Conventional flyback controllers use photocouplers in the feedback circuit that monitors the output voltage, making the circuit complex and large.

On the other hand, Analog Devices' flyback controllers use a boundary mode that allows output voltage regulation without the need for a photocoupler. This makes it possible to reduce the number of parts and downsize the circuit while maintaining sufficient regulation accuracy.

Many traction inverters have an isolated power supply for each of the six isolated gate drivers. With Analog Devices solutions, you can achieve significant inverter miniaturization.

An example of a flyback controller is the LT8301, which has a built-in 65V/1.2A switch. It achieves an input voltage range of 2.7V to 42V, making it ideal for automotive applications with 12V batteries.

If you need a little more supply current, we recommend the LT8302 isolated power controller with a built-in 65V/3.6A switch. There are several other lineups, so you can select according to the input/output specifications.

ADI's inverter solutions offer a variety of options to match system specifications and design concepts, and contribute to the realization of compact inverters with the highest levels of safety and power efficiency.

An evaluation board is provided for the solutions introduced in this article. You can easily try it. If you are interested, please feel free to contact us.

Application example

・ BEV (electric vehicle)

・HEV (hybrid vehicle)

・PHEV (plug-in hybrid vehicle)

Inquiry

If you have any questions regarding this article, please contact us below.

In addition, we held a seminar in the past related to this article, "Improving the drive performance of EVs! Analog Devices' inverter solution seminar." If you would like to request materials for the seminar held, please contact us with the message "Increase the driving performance of EVs! Request materials for analog devices' inverter solution seminar".