LTC3810 100V Current Mode Synchronous Switching Regulator Controller

[majdi]

Hello and good day all, i try to build high voltage input voltage regulator to 12V 3-5A. My input voltage near 86-90V battery. What i need is to step down the 86-90Vdc to 12vdc.

After google up for few day, the best component to use is LTC3810 ic. It has 15-100V input rating. The datasheet is complete, but i need to ask more people for the rest of component rating.

The circuit url :
http://www.linear.com/product/LTC3810

I need help for circle marked component, for the capacitor it the voltage rating is universal? and The resistor should i use 5Watt rating? and also the 100k, some circuit show it not resistor but Radial lead inductor. Any one have use these LTC3810 ic can share more information to build this circuit.

Here more example for this circuit :
http://www.dz863.com/circuits-36-815449863-LTC3810_TYPICAL-APPLICATION-Application-Circuit/

 

[chopnhack]

I need help for circle marked component, for the capacitor it the voltage rating is universal? /

Hi majdi - for Cin - I would recommend at least 2.5x your input voltage, here is an inexpensive choice: Rubycon 250BXC22MEFC10X16

Your circled resistors don't need to have such a large watt rating - the incoming power is at 90v - 90v/261k ohm = very low watts. Inductors act as resistors as well, however, I will allow others to answer more of your questions

 

[majdi]

Hi, chopnhack, thank you for your advise and help. Just order the component. Hope it work haha