Electronics > Beginners
[SOLVED]How do I calculate the power dissipation for a ULN2003A Darlington array
SlowBro:
How do I calculate the power dissipation for a ULN2003A Darlington array? Is it Vce(sat) * Ic?
https://www.seeedstudio.com/document/pdf/ULN2003%20Datasheet.pdf
StillTrying:
Is it Vce(sat) * Ic?
Yes, assuming they're fully switched on, the data sheet gives the typical saturation voltages 100mA to 350mA, 0.9V to 1.3V.
...add a few mW for the resistors and 1st transistor.
SlowBro:
So for example I want to using multiple channels drive 20 LEDs at 20mA each for 400mA total. Dissipation = 1.6V (max) Vce * 400mA = 640mW. Did I get that right?
StillTrying:
one of these channels drive 20 LEDs at 20mA each for 400mA total.
I was going to say it might be a bit higher with 400mA though the one channel, 550 to 600mW, but you've already done it.
Don't forget to add the other channels. I can't work out the Max. allowed dissipation from that data sheet.
SlowBro:
Yeah, all channels combined it will be pushing the Rth j-amb max but the on time will be brief so I feel comfortable about it. Thanks!
Navigation
[0] Message Index
[#] Next page
Go to full version