Stole this from a site...want to get it down for when I need to design the power board.
----
The power dissapation is equal to the voltage drop across the regulator x the current draw.
For example, suppose the supply voltage is 5v, and you're regulating down to 3.3v. This is a 1.7 volt drop. Multiply this by the current, say 100 mA, which equals 170 mW.
If the supply voltage is higher, the dissapation will be greater. A 12v supply would increase the dissapation significantly:
(12 - 3.3) x 100 = 870 mW.
 |
Tuesday, 9th of March 2010
|
Tuesday, 9th of March 2010
del.icio.us