From 40V-100Vdc to 8V-12Vdc to 5Vdc

Thread Starter

Vindhyachal Takniki

Joined Nov 3, 2014
1. I have a voltage range of 40V-100Vdc & have to make 5vdc from it and power a microcontroller with it. Max current is 700ma.
2. Since have to measure analog so I want to first make a voltage of around 8-12Vdc then use a linear regulator like LM7805 to make 5Vdc.
3. I need module only. SO I checked for dc-dc buck. they are very costly >$100.
4. For lost cost option I see some people use a resistor & zener first to drop the voltage but I didnt find this good solution.
5. Ground of 40V-100Vdc should be same as of 5vdc & system should be non-isolated.
Any low cost solution for this. I want module based system in this.


Joined Oct 15, 2009
I doubt that's true in general.
My comment there was that they could use discrete parts,etc.. and make their own/pcb,etc... if there is any decent volume it would certainly be cheaper than $40..
Now I did not include Design/Testing,etc.. costs into that..