Any step away from the trusty 78xxx series will involve tradeoffs. You can save a few cents with a 5.1 volt zener, at the price of more power dissipation, more heat, and poorer regulation. Pics work great with zener regulators, though, in many circuits. (for instance in 1 million steam irons I designed.) Anything else you design with will take more design effort. If minimizing your design effort is a goal, 78xxx parts are ideal. When you have to bang out a quickie lab instrument by noon, scratching your head over a complex regulator isn't what you want. Low dropout regulators will generally cost a little more, maybe a little or maybe a lot more, but still retain the cookbook low-parts count quality in many situations. Buck or boost regulators using a flyback coil can make 5 volts out of 1.5, can make 5 volts out of 24, (maybe they can even make water out of wine? ) wihtout consuming a lot of power in the process, at the price of extra cost and parts count plus design headaches. National has reduced this to a cookbook process in some of their parts, though. I have actually found very few situations where the good ol' 78XX series doesn't serve well. Of course, nothing I design is optimized for long battery life so your mileage will vary. For hobby use or lab one-offs, I try to keep 78L05's, 78M05's (TO220 case) , 78M12's, and a few 317T's (adjustable) in stock at all times. I can't count how many handbuilt prototypes I have built using these handy little parts. -- Lawrence Lile Anthony Toft Sent by: pic microcontroller discussion list 03/16/2004 06:50 AM Please respond to pic microcontroller discussion list To: PICLIST@MITVMA.MIT.EDU cc: Subject: {EE:] Whis is the better regulator to use? Was Re: [OT:] What Does Nanowatt Technology Give? > Not stupid in the least. In fact a lot of novices brag about using low power > parts with a battery. But further into the discussion you realize that they > are using a linear regulator that's sucking down almost half the battery's > power. So which are the better regulators to use? As a non EE I generally stick to what I know, and I have used the 78l05 in my project, but if that's not the best (and it strongly sounds like it) I would like to educate myself in the better devices. The thing I like with the 'l05 is that it works great with a handful of caps, in a 'cookbook' solution, if I want 12v just use the 'l12. Are there other devices with similar recipe solutions, I'd like something that's in the manner of do this, do that and feed volts in here and get smooth volts out there. I don't really need the recipe as I realize the datasheets are out there, but which datasheets should I read and why. Thanks -- Anthony Toft -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu