Power conversion, such as AC-DC or DC-DC power conversion, is required in many applications. An AC power supply at 230 V may be first converted to a DC power supply at a lower voltage for example 48 V. Some applications require an even lower DC voltage, for example 12 V or around 2 volts, for example 1.8 V. This may be provided by using a multistage DC-DC conversion system, in which, for example, a 48V DC supply is converted into a 12 V DC supply which in turn is converted to a 1.8 V output voltage supply. As each conversion step typically has an efficiency which is less than 100%, the efficiency of the entire conversion process may be further reduced as the number of conversion stages increases. Additionally, each conversion stage is associated with components to provide the power conversion circuit which, in some applications, may lead to an undesirable occupation of space.
In some applications, such as power conversion for use in data centres, in which an output voltage of around 1.8 V DC is required, a circuit providing a higher DC-DC step-down conversion ratio would be desirable, for example to convert a 48 V DC input voltage into a 1.8 V DC output voltage. Additionally, it is desirable to provide such a conversion circuit and modules for providing the circuit which have a lower volume and a higher power rating per unit volume, which is also referred to as power density.