AN3276 Datasheet, PDF (19/22 Pages) STMicroelectronics – ST solution for efficiency improvement in PFC applications

AN3276
4
Conclusion
Conclusion
The BC² circuit uses the soft switching method with a unique non-dissipative recovery
circuit. STMicroelectronics has introduced the specific diodes suited for the BC² concept to
improve the CCM PFC performance as shown in Table 4.
This circuit supports the actual energy efficiency recommendation at 20%, 50% and 100%
of rated power supplies.
Table 4. BC² benefits in 450 W PFC, 140 kHz
Criteria at 90 V rms
SiC diode
BC² circuit
Benefits
Efficiency
Power MOSFET
temperature
Power density at
iso-efficiency
EMI
Boost rectification cost
92.5%
90 °C
State of art
Acceptable with
dI/dt < 1000 A/µs
> 0.2 € per 100 W
93.7%
72 °C
Improve, save 5.4 W
Acceptable with
dI/dt < 100 A/µs
>> 0.2 € per 100 W
+1.2%
-18 °C
+1.2% gain
Soft switching
Mass market
Doc ID 17975 Rev 1
19/22