last highlighted date: 2023-10-20
Highlights
- FC Inductor and input line current waveforms in the three different operating modes0 1 10 4- 2 10 4- 3 10 4- 4 10 4-051015Iin t( )IL t( )tCritical Conduction Mode (CrCM)
- Note: how CCM CrCM DCM differs in current-time graph
- For a boostconverter, the following are some major MOSFET selection considerations for high efficiency applicationdesign: Low figure-of merits - RDS(ON)*Qg and RDS(ON)*Eos
- Note: boost converher MOSFET selection guide
- Fast turn-on/off switching to reduce the device switching losses Gate plateau near middle of gate drive range to balance turn-on/off losses Low output capacitance Coss for low switching energy and to increase light load efficiency Drain-source breakdown voltage VBR(DSS) to handle spikes/overshoots Low thermal resistance RthJC. Package selection must consider the resulting total thermal resistance fromjunction to ambient, and the worst case surge dissipation, typically under low-line cycle skipping andrecovery into highline while ramping the bulk voltage back up. The body diode commutation speed and reverse recovery charge are not important, since body diodenever conducts in the CCM boost converter.
- Note: Boost converter MOSFET selection guide
- Selection of the optimum on-state resistance of a specific CoolMOS™ series is based on the balancingbetween switching losses and conduction losses of the device at a targeted load point.