> Date: Fri, 9 Nov 2007 10:29:39 -0500 > From: "David VanHorn" > Subject: [EE] Automotive transient protection > I'm having trouble finding solutions for transient protection on the > automotive DC bus. > > I need to find something that will work on a 24V system, and ideally > also on the new 48V (or 56 or whatever they are calling it) consumer > automotive bus. > > I can't use regulators with built in protection, I need this external. > > Can someone point me in the right direction? > > What sort of transients and surges do you have to protect against? I've done a number of designs for 28V military vehicles. The usual circuit is a high side switch that turns off before the max. regulator input voltage is exceeded. On the input side of this is an LC filter (primarily for EMC) and the output side has a TVS to catch the fast transients. The circuit is designed to handle 100V for 100ms and 250V for 1uS. It helps to have an automotive regulator on the input to the equipment because it raises the voltage at which you have to turn off the circuit and gives more flexibility with the TVS voltage. I would expect that there are off the shelf filters for regular automotive applications. Have you tried Vicor or XP Power? Cheers James -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist