Indicator LED brightness and Manufacturer binning - Page 1
Forum section: electronics / projects

author: ajo518
author_rank: Contributor
timestamp: July 22, 2025, 08:44:49 pm
content: So I am making a board that will have a bunch of Inputs and outputs that I want to show the status of with LED's. There are also chips with status outputs that I want to showwith red LEDs for errors.I have picked out an SMD LED in each color from Osram in the same family with roughtly the same forward voltage and brightness at the same test current. I got a couple of each from digikey and used a potentiometer to find the current to run them at to get the brightness that I am looking for. I then found the current that was for each LED. Long story short when I scaled the currents to the candela state on the data sheet I ended up with 1 for the red LED and 9 for the green LED. I think this should be the same ish goven that they appear to be the same brightness?That then got me down the road of LED brightness binning from the factory. Wondering if I got bright of one type and the dimmest of the other for example) The datasheet calls out a bunch of different coded bins for brightness and forward voltage. The part number seems to have the full range of bins in it not one speciffic bin. EG. it is LE-xxxxx-S1J1. Where S1 is the smallest bin and J1 is the largest bin.Here is one of the parts I am looking at:https://www.digikey.com/en/products/detail/ams-osram-usa-inc/KG-EELP41-22-PHRH-35-A8J8-20-R18/24765242Is there a way to order a speciffic bin? Is that not something that is done for low volumes? I also could not find the speciffic bin on the parts that were delivered. IS that something you only get if you order a whole reel?How is this handeled comonly? Do people order speciffic bins? Is it printed on each real? Do peple just take the middle ground and design for that and live with the variance?What is the normal design procedure here? Choose a number for brightness and go for that or is it usually more just by testing the given LED?I am sure I am overthinking this for a simple indicator...Any help is appreciated!

author: PCB.Wiz
author_rank: Super Contributor
timestamp: July 23, 2025, 12:47:01 am
content: Quote from: ajo518 on July 22, 2025, 08:44:49 pmUnless there is a specific part code, usually you cannot order which bin, as they get a spread from the fab.It should be labeled on the reel, but often distis will not carry that info forward as the next reel may differ.The binning is mainly focused at users ofmany leds the same colour,but you are right, if working with multiple colours then reel labeled bin select does not help much.Some designs order the LEDs and then change the BOM for that build batch, if you really want to try to reduce spreads.

author: jwet
author_rank: Frequent Contributor
timestamp: July 24, 2025, 03:36:42 pm
content: Binning is usually a special order/contact factory type of deal. Depending on the spread of brightness at the manufacturer and your requirements, it will often affect pricing. Specials generally start at 10000 pieces from most vendors. Use a first tier opto supplier if possible (Broadcom, Taos, etc) and contact their apps line and work your way through to the business manager for that product line. He can quickly tell you MOQ's, pricing bumps and yields. Doing this through disti is difficult and if your volumes aren't very high, it won't work. What I've done doing specialized low volume stuff is to get an estimate of the yield of your binning and overbuy and do the sorting in your lab. If you build a test fixtrure, you could have a tech go through a lot of parts in a day to get what you need. This works for very cheap stuff like LED's etc.Some LED drivers from Maxim and TI that handle lot of LED's, 7 Segs or arrays etc. will have a current tweak value register that will let you tweak the current in the driver. This was common for seven segment drivers where you might have 8 digits for a frequency counter or pinball machine. (look at MAX7219 and similar)