Content originally posted in LPCWare by IanB on Fri Jan 02 06:00:54 MST 2015
I'm just about to use the LPC1518 in the 100-pin package, which has six of each Vdd and Vss pins.
How many of these need to be connected for the device to work properly? Connecting all the Vdd pins together is the only thing that is preventing me from getting the project on a single-sided pcb!
Having checked an LPC1111 with a continuity tester, I know that its two Vdd pins are not internally connected, and I found out the hard way that they both have to be connected for it to work properly. Is it the same with the 100-pin TQFP? I couldn't find much information in either the data sheet or the user manual, just that the "absolute maximum" rating for the supply current is 100mA per supply pin.
If the supply pins are not internally connected, then how would I calculate how much current goes down each pin?