High voltage constant current circuit ideas

[Biggles]

I have been asked to make a circuit to regulate out up to 4A DC,  48V DC with input up to 100V DC. Switching design for less loss. In the past I have used 3525 PWM for boost application, this is buck application and also need a current feedback. I am hoping for relatively simple solution.

Constant current circuit is not one I have much experience with, so I am asking for any pointers or start suggestions. Any help or advice much appreciated.

[Old_but_Alive]

have a look at the linear tech LT3080, the datasheet shows using it as a current source ( you will need 4 ), and use a switching pre-reg to give the LT3080's just enough voltage to operate, without excessive heating.

otherwise, there's loads of good chips and data on driving HB LED's, which are driven as constant current.


the design depends on cost, accuracy, ripple etc etc