Hi there, Bob. I'm glad that you commented on Mr Smiley's message - I did not=20 receive that message. But you nailed it when you suggested that it won't work. Not only=20 does each segment have three LEDs in series, but the display is=20 direct-drive (no multiplexing). The display connector has 37 connections. That said - I wasn't aware of the TM1638. I'll keep it in mind for=20 other projects. I have considered using 4- 74HC595 shift-register chips as a=20 high-side driver by shifting the ground pin by 3.5 Vdc or so, then=20 using simple level-shift circuits for the data, clock, strobe=20 pins. But the maximum package current for the HC595 is 70mA and I=20 want to drive the segments at 20mA each (140mA total per package). I also considered using the CD4511 decoder/driver chips that the=20 original manufacturer used. Downside with those is that I truly do=20 NOT like the "6" and "9" digits from the 4511 (top / bottom bar is=20 missing) **and** I can't send arbitrary segment patterns to the=20 display (HELP, OUCH, On, on, oFF, OFF, etc). You get the picture. Sephro suggested just adding a whack of jellybean dual PNP=20 transistors - that is still an option. So - I'm still looking for suggestions. This doesn't need to be done=20 now but we've been sitting on these displays for quite a while now=20 and it would be nice to make use of them. Many thanks! dwayne At 01:29 PM 3/6/2019, Bob Blick wrote: >OP needs to drive three LED in series strings. I don't think TM1638=20 >work above 5V. The price is right though. >Cheerful regards, Bob >________________________________________ >From: piclist-bounces@mit.edu on behalf of=20 >Mr Smiley >Sent: Wednesday, March 6, 2019 11:28 AM >To: piclist@mit.edu >Subject: Re: [EE] Looking for recommendation: high-side LED display driver > >TM1638 > >:0) --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA 780-489-3199 voice 780-487-6397 fax 888-489-3199 Toll Free www.trinity-electronics.com Custom Electronics Design and Manufacturing --=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 .