Hi Dwayne, I don't have any part numbers for you, but I do have a couple of thoughts a= bout LEDs. mcd is a measurement of brightness at a particular angle, so the= lens(and viewing angle) plays a big part in that number. Most SMT LEDs hav= e no real lens and the viewing angle is large, >100 degrees and the mcd rat= ing is correspondingly low. Compare this to a through-hole LED with a clear= lens and a viewing angle of 30 degrees or less. So you might not look too = hard at the mcd rating. The other thought relates to color. The short-wavelength greens are very ef= ficient but have longer lifespan than blues. They also have a high voltage = drop, similar to blue LEDs, so if you are running at 3.3 volts you'll need = to pay close attention to your dropping resistor after choosing your exact = LED. The greens I'm talking about emit at about 520nm. Happy hunting! Friendly regards, Bob ________________________________________ From: piclist-bounces@mit.edu on behalf of Dwayne= Reid Sent: Friday, May 27, 2016 12:09 PM To: pic microcontroller discussion list Subject: [EE] Looking for high-efficiency SMT LEDs Good day to all. I'm looking for a single-color SMT LED that gives me reasonable brightness when operating at less than 1mA current. Neither size or color is critical - what I'm after is lowest cost combined with highest brightness. Here's where I'm coming from. We currently use 5mm through-hole LEDs in most of our boards. The green and blue LEDs are stunningly bright - even when run from only 0.2mA or so. I've spent significant time looking for SMT versions of bright LEDs. Unfortunately, most of the offerings from Digikey are way less than 1000 mcd when running at 20mA. I need reasonable brightness when running from 0.5mA or so. I'm in the design phase right now but I'm at the point where I have to make decisions regarding the voltage dividers that these LEDs are in series with. These decisions ripple through my entire design, up to and including the power supply. Because these LEDs are near screw-terminal blocks, physical size isn't an issue. But I want machine-installable LEDs - ideally with a flat top (as opposed to a dome top). Initial annual quantity would be in excess of 10k but will be increasing as I migrate more of my current through-hole designs to SMT. I'm okay with Asian suppliers so long as the product that I receive is of consistently high quality. I'm hoping that someone can refer me to a supplier. Many thanks! dwayne --=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 .