guys i'm going to use two 40v mosfet in synchronous mode of operation for my buck converter. I have chosen SON package type. I have doubt regarding its structure. It has 4 drain, 3 source, 1 gate. Can we use two mosfet in the same single package or 2 different packages are required. I can't understand why different modules various drains and source are available for single package.I 'm sharing the IC which i'm going to use. Suggestions are welcome.
Personally, I make symbols like this for the schematic, so I can see the pin numbers. But other people probably have other ways of doing it. In this case you've got the complication of the thermal pad underneath and you've got to decide whether 5,6,7,8 and the thermal pad are all one, or whether they are all separate, or whether you put the thermal pad in by hand afterwards. The Eagle experts here should be able to guide you as to the best way to do it with that package. [You might need a new question in the Eagle area.]
Your tracks [source and drain] are going to be areas of copper at these sorts of current levels (I'm asssuming you haven't chosen a 30A MOSFET for switching an amp or two). So the source pins will all fall within the source copper area and the drain pins and heat pad will fall within the drain copper area. Do use a track for the gate, though, because you want to keep the capacitance down (the gate charge figure is high enough already without adding to the load for your controller chip).
Personally, I make symbols like this for the schematic, so I can see the pin numbers. But other people probably have other ways of doing it. In this case you've got the complication of the thermal pad underneath and you've got to decide whether 5,6,7,8 and the thermal pad are all one, or whether they are all separate, or whether you put the thermal pad in by hand afterwards. The Eagle experts here should be able to guide you as to the best way to do it with that package. [You might need a new question in the Eagle area.]
Your tracks [source and drain] are going to be areas of copper at these sorts of current levels (I'm asssuming you haven't chosen a 30A MOSFET for switching an amp or two). So the source pins will all fall within the source copper area and the drain pins and heat pad will fall within the drain copper area. Do use a track for the gate, though, because you want to keep the capacitance down (the gate charge figure is high enough already without adding to the load for your controller chip).
