Isolated DC-DC convertor
Posted: Tue Oct 20, 2015 7:54 pm
I need to control a MOSFET. But the MOSFET must be separated powered. There are commercial isolated DC-DC convertors available, like the e.g. SN6501 see figure. But why using this IC when a microchip is available?
Switching the gate of the MOSFET by means of a transformer, like in the figure, seems a bad idea to me. That will not be fast enough. But the microchip can countinously produce a 50% PWM which can be transformed to the 5V needed for the gate. The switching of the gate can be done by means of an optocoupler, powered by this 5V (at the collector of the optocoupler). The current will be extremely low.
My question is: should it be possible to use the PWM as source for the transformer?
With kind regards
Jan Lichtenbelt
Switching the gate of the MOSFET by means of a transformer, like in the figure, seems a bad idea to me. That will not be fast enough. But the microchip can countinously produce a 50% PWM which can be transformed to the 5V needed for the gate. The switching of the gate can be done by means of an optocoupler, powered by this 5V (at the collector of the optocoupler). The current will be extremely low.
My question is: should it be possible to use the PWM as source for the transformer?
With kind regards
Jan Lichtenbelt