SNVS346H November 2007 – October 2024 LM3481
PRODUCTION DATA
As in a boost converter, the parameters governing the selection of the MOSFET are the minimum threshold voltage, VTH(MIN), the on-resistance, RDS(ON), the total gate charge, Qg, the reverse transfer capacitance, CRSS, and the maximum drain to source voltage, VDS(MAX). The peak switch voltage in a SEPIC is given by:
The selected MOSFET should satisfy the condition:
The peak switch current is given by:
Where ΔIL1 and ΔIL2 are the peak-to-peak inductor ripple currents of inductors L1 and L2 respectively.
The rms current through the switch is given by: