Hi Mario, Geiger counter? Nixie clock? Photomultiplier tube? With that high a voltage ratio, you can't use a typical flyback + inductor = topology, you will need a transformer or autotransformer. You can still use= a single power device. Even if you lowered the switching frequency so the "off" time is still in a= reasonable range for the inductor/diode/switch, most switcher chips won't = go to the extreme duty cycle you'd need (98%+) to make a simple inductor wo= rk. I usually figure any voltage ratio higher than 1:5 needs a transformer = unless the current requirements are very very small you can push it to 1:7.= Definitely not 1:50. On the other hand, I have made plenty of little transformers out of cheap i= nductors. You could wind a second layer on top of a typical "spool" inducto= r and you'd have yourself a fine little transformer with your hand-wound pr= imary. Start with something like this: https://www.digikey.com/product-detail/en/bourns-inc/RLB9012-471KL/RLB9012-= 471KL-ND/1969612 Peel the heatshrink off it first, and use thicker wire for your primary. An= d keep fingers crossed about high voltage breakdown. I've also salvaged transformers from electric bug swatters and photo flashe= s, but they need to operate at audible frequencies. Cheerful regards, Bob ________________________________________ From: piclist-bounces@mit.edu on behalf of Mario Sent: Tuesday, February 13, 2018 2:33 AM To: Microcontroller discussion list - Public. Subject: [EE] 7-16V to 350-400V SMPS boost IC? Hello, could you advice me some SMPS IC (possibly with integrated MOSFET) to boost from around 7-16V to around 350-400V with at least 1A average input current please? Thank you. Kind regards, Mario --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .