Although inverters (AC/DC conversion) are modernizing refrigerator designs, power devices such as MOSFETs are taking this home appliance one step further by maximizing energy efficiency and reducing audible noise. Refrigerator inverter designs increasingly adopt digital inverters to adapt to consumers' habits of running at various speeds throughout the day.

The inverter enables the compressor to accelerate during the day and decelerate at night, saving 20% ​​to 30% of electricity bills. In other words, the digital compressor can adjust the speed according to the actual cooling demand of the refrigerator.

However, until now, compressor design has been dominated by power modules for AC/DC conversion. As Samsung announced the use of MOSFETs to further reduce energy consumption, especially under light load conditions, this situation has changed. The transition from power modules to discrete devices (such as MOSFETs) is expected to increase power efficiency by 1.7%.

It also leads to a radiatorless design, which reduces system costs by 10% and extends compressor life. Samsung uses Infineon’s 600V CoolMOS PFD7 super junction MOSFET for the compressor driver. Infineon claims that CoolMOS PFD7 MOSFETs have improved the soft recovery index and have the industry's fastest reverse recovery time (trr); this makes them very suitable for home appliance motor drivers.

In addition to the 600V CoolMOS PFD7 for compressor drive, Samsung also uses Infineon's CoolSET Gen 5 integrated power stage for AC/DC conversion and EiceDRIVER gate driver IC.

This will be Samsung's first inverter refrigerator that uses discrete components instead of power modules in the compressor. This marks a key improvement in the design of digital inverters and another important step in the journey of refrigerators from energy-consuming household appliances to green refrigerators.

Majeed Ahmad, editor-in-chief of EDN, has been involved in the electronic design industry for more than two decades.

I assume this uses a variable speed drive, which is now driven by fast-side MOSFETs. Because home appliances are not regulated by the FCC, what about the corresponding EMI?

You must log in or register to post comments.