Post by thread:answer = ULN2803, now, where to get it?

Thanks for the info that the part I am looking for is the ULN2803. Now, does anyone know of a cheap, no haggle place to buy 10 pieces? The Motorola web site says they're $0.61 each in 20 piece quantities but I think FAI has a $50.00 minimum. Or should I buy a hundred and resell them? Also, the specs list 500mA max collector current. Is there a total max for all channels on? (Like the PIC, 25mA sink per pin, 50mA max per port). I couldn't find it. Thanks again. Dave

At 04:45 PM 10/21/96 -0700, you wrote: >Thanks for the info that the part I am looking for is the >ULN2803. Now, does anyone know of a cheap, no haggle place to buy >10 pieces? The Motorola web site says they're $0.61 each in 20 >piece quantities but I think FAI has a $50.00 minimum. Or should >I buy a hundred and resell them? > >Also, the specs list 500mA max collector current. Is there a total max >for all channels on? (Like the PIC, 25mA sink per pin, 50mA max >per port). I couldn't find it. > >Thanks again. >Dave > Well, Mouser Electronics (1-800-346-6873) (http://www.mouser.com) has the uln2803 listed in their catalog for 1.08. You'll have to call to see if it's in stock. As for total max current for the device, I think you are okay as long as you do not exceed the total package power dissipation of 2.25W (this gets de-rated above 25 degree centigrade). Also, depending on your application remember that all the collectors are connected through diodes to COM (pin10). I screwed up once on a design and let this pin float, and boy did I get some weird behavior. Please note: all specs come from a Sprague data book that is probably out of date. Hope this helps..... carl ---------------------------------------------------------------- Henry Carl Ott N2RVQ | talk/chat carlott@204.74.7.186 spam_OUTcarlottTakeThisOuTinterport.net | http://www.interport.net/~carlott/ ---------------------------------------------------------------- "A day job...in an office? My worst nightmare!"-Ticknophobia

Hi >Thanks for the info that the part I am looking for is the >ULN2803. Now, does anyone know of a cheap, no haggle place to buy >10 pieces? The Motorola web site says they're $0.61 each in 20 >piece quantities but I think FAI has a $50.00 minimum. Or should >I buy a hundred and resell them? >Also, the specs list 500mA max collector current. Is there a total max >for all channels on? (Like the PIC, 25mA sink per pin, 50mA max >per port). I couldn't find it. Dave, search the maximun in the maximun power disipated, use the worst case in the drop of the outputs and multiply by the currents. You CAN'T handle 500mA in all the outputs, at least in the TI version of the ULN2003. >Thanks again. >Dave ******************************************************************************** Salvador Eduardo Tropea (SET) - .....salvadorKILLspam@spam@inti.edu.ar Work: INTI (National Institute of Industrial Technology) Sector: ICE (Electronic Control & Instrumentation) Post (Home): Curapaligue 2124 - Caseros (1678)- Buenos Aires - Argentina