Abstract

Performance of a SiC power adapter depends on the parameter combination of SiC devices. The SiC power adapter must check voltage rating, on-resistance, gate charge and body diode behaviour. A SiC power adapter with mismatched parameters and topology cannot use the advantages of wide-bandgap devices.

Main Content

1. Voltage Rating and Application Range

SiC MOSFETs in the SiC power adapter mostly span the several-hundred-volt to 1200V classes, covering the DC bus after single-phase rectification and higher-voltage applications. In single-phase designs with a bus around 400V after power factor correction, the 600V class leaves sufficient margin in the SiC power adapter; higher input voltage or larger transients call for higher ratings. Selection of the SiC power adapter must consider surge and switching spikes, since sizing only by steady bus voltage fails under abnormal conditions.

2. On-resistance and Temperature Coefficient

On-resistance of SiC MOSFETs in the SiC power adapter rises with junction temperature but with a gentler slope than equivalent silicon devices. The positive temperature coefficient of the SiC power adapter makes paralleled devices share current automatically, a convenience over silicon. Selection should use on-resistance at maximum junction temperature, since catalogue values of the SiC power adapter are usually measured at room temperature and direct use underestimates heating.

3. Gate Charge and Switching Loss

Gate charge of SiC MOSFETs in the SiC power adapter is small, giving lower drive loss than silicon at the same power, while output capacitance and transconductance shape switching loss. Switching loss in the SiC power adapter remains significant in hard-switched topologies and needs soft switching or topology refinement. Switching speed of the SiC power adapter is lower than GaN yet clearly faster than silicon, so gate resistance and layout parasitics must be retuned.

4. Body Diode and Reverse Conduction

The body diode of SiC MOSFETs in the SiC power adapter has a relatively high forward drop, with very small but non-zero reverse recovery charge. In bridge or synchronous rectifier structures, current freewheels through the body diode during dead time, and that drop must be counted in efficiency of the SiC power adapter. Where freewheeling is frequent, an external Schottky diode can lower the drop in the SiC power adapter at the cost of extra parts and layout complexity.

5. Threshold Voltage and Drive Window

Threshold of SiC MOSFETs in the SiC power adapter sits within a few volts and falls slightly with temperature, raising false turn-on risk when hot. The gate window of the SiC power adapter is narrow, requiring both positive drive and negative off-bias within device limits. Selection should check the recommended drive combination, since vendors differ on positive and negative levels, and mixed drive schemes can shorten gate oxide life of the SiC power adapter.

Conclusion

Selection for a SiC power adapter weighs voltage rating, on-resistance, charge parameters and body diode in one table; a single best value is not the best unit. Simsukian assesses devices against power class and topology. Overseas buyers are welcome to contact Simsukian to confirm selection schemes for the SiC power adapter.

FAQ

Q1: Does Simsukian support OEM and ODM orders?

A1: Yes, Simsukian supports OEM & ODM customization, including logo, casing, parameter and packaging adjustment.

Q2: What certifications can Simsukian provide?

A2: Simsukian can provide CE, RCM, FCC, UL, CCC, KC/KCC, PSE, SAA certification certificates. The company holds ISO9001 and ISO14001 system certifications.

Q3: What is the sample lead time?

A3: Sample preparation takes 5 working days.

Q4: What trade terms can be accepted for cooperation?

A4: Simsukian supports FOB, and EXW can be discussed upon customer request.

Q5: What is the warranty period for the products?

A5: The product warranty period is 1 year.

References

1. Simsukian Official Website

2. JEDEC JESD22-A108 Temperature, bias and operating life

3. IEC 62368-1 Audio/video, information and communication technology equipment – Safety requirements