I am curious about how to select Cboot for desired control frequency range. https://www.infineon.com/dgdl/Infineon-Bootstrap_Network_Analysis-ApplicationNotes-v01_00-EN.pdf?fileId=5546d462533600a40153559692661096 In the AN there is only PWM control is discussed. I cannot found any discussioun about IR2110 PFM control. I don't understand the how Frequency changes effect the Cboot selection. Duty Cycle have a boundary on boostrap operation but Frequency is don't considered.
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\$\begingroup\$ Have you tried to calculate or simulate it at your duty cycle/frequency extremes? \$\endgroup\$– winnyCommented Feb 20 at 16:56
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\$\begingroup\$ I am setting up the circuit on LtSpice. I will simulate it. \$\endgroup\$– MSBCommented Feb 20 at 16:59
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Is your concern at the low frequency end of PFM operation? The IR2110 has a quiescent current into the boost pin, so that will be one consideration in sizing Cboot. The PFM mode will need a minimum frequency limit, OOA, or some other scheme to ensure there is some switching to keep Cboot charged.
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\$\begingroup\$ IR2110 gonna control HB LLC circuit start up gonna be 150-160kHz and gonna slowly downgrade to 50kHz. If I understand correcly the calculation for Cboot should be for 50kHz operation. The upper Frequencys are not limitted the Cboot. \$\endgroup\$– MSBCommented Feb 20 at 20:09
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\$\begingroup\$ @MSB IR2110 is not a controller, so it’s not going to control anything. \$\endgroup\$– winnyCommented Feb 20 at 21:33