“When discussing high power density and high frequency applications such as switched mode power supplies (SMPS) or power factor correction (PFC), it is known that silicon bipolar diodes are limited due to their reverse recovery behavior and the resulting switching losses The efficiency of these systems. Therefore, a material with a higher band gap is preferred, such as silicon carbide (SiC) or gallium arsenide (GaAs). So far, GaAs power devices are mainly used below 300 V, and 600 V applications such as PFC are considered to be the ideal choice for SiC devices. But now, a new generation of 600 V GaAs power Schottky devices has proven to be a cost-effective and rugged alternative.

“

When discussing high power density and high frequency applications such as switched mode power supplies (SMPS) or power factor correction (PFC), it is known that silicon bipolar diodes are limited due to their reverse recovery behavior and the resulting switching losses The efficiency of these systems. Therefore, a material with a higher band gap is preferred, such as silicon carbide (SiC) or gallium arsenide (GaAs). So far, GaAs power devices are mainly used below 300 V, and 600 V applications such as PFC are considered to be the ideal choice for SiC devices. But now, a new generation of 600 V GaAs power Schottky devices has proven to be a cost-effective and rugged alternative.

The increase in power density is one of the main tasks of today’s power Electronic equipment: the system size should be minimized, while generally increasing the power output of user applications. There are two ways to deal with this challenge:

**Reduce losses through more efficient power electronics**

The number, weight and size of active and passive components are usually reduced by increasing the switching frequency.

An important example is the optimization of power factor correction systems (PFC). Boost converters with PFC can usually operate in continuous current mode (CCM) or discontinuous current mode (DCM). However, in DCM, due to high current peaks, most circuit components must be increased in size, which in turn requires complex EMI filtering. Moreover, the system tends to be unstable under light load.

Figure 1 Typical forward characteristics of 300 V / 10 A type 1st and 2nd generation GaAs and SiC Schottky diodes

Considering the general physical parameters of Si, SiC and GaAs, SiC seems to be the material of choice for high-frequency power devices. It can withstand the highest electric field, resulting in a diode with a high breakdown voltage and low forward voltage drop. In addition, it has the lowest thermal resistance and can achieve a higher on-current density.

However, gallium arsenide has some advantages that must be considered. Due to the high positive temperature coefficient of the forward voltage drop, the non-repetitive peak current in SiC is limited. Therefore, the device size must be large enough to avoid damage by overcurrent. For the second generation of the same average current rating, IXYS GaAs devices can provide more than twice the surge current.

The Links: **LQ050Q5DR01R** **2SB1424T100Q**