ZHCS519G April 2000 – May 2019 LM2585
PRODUCTION DATA.
The maximum output voltage of a boost regulator is the maximum switch voltage minus a diode drop. In a flyback regulator, the maximum output voltage is determined by the turns ratio, N, and the duty cycle, D, by the equation:
The duty cycle of a flyback regulator is determined by the following equation:
Theoretically, the maximum output voltage can be as large as desired—just keep increasing the turns ratio of the transformer. However, there exists some physical limitations that prevent the turns ratio, and thus the output voltage, from increasing to infinity. The physical limitations are capacitances and inductances in the LM2585 switch, the output diode(s), and the transformer—such as reverse recovery time of the output diode (mentioned above).