LPC MicrocontrollersのトピックRe: Power supply pins

Power supply pins

lpcware — Wed, 15 Jun 2016 17:09:51 GMT

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?

Re: Power supply pins

lpcware — Wed, 15 Jun 2016 17:09:52 GMT

Content originally posted in LPCWare by starblue on Mon Jan 05 10:12:16 MST 2015
My understanding is that you should always connect all Vdd/Vss pins, and use a decoupling cap close to each pair.

Re: Power supply pins

lpcware — Wed, 15 Jun 2016 17:09:53 GMT

Content originally posted in LPCWare by nerd herd on Mon Jan 05 11:43:41 MST 2015
Hi IanB,

In order to ensure correct operation, it is recommended to connect all the Vdd pins to the digital 3.3V rail with a decoupling capacitor like Starblue stated.

Re: Power supply pins

lpcware — Wed, 15 Jun 2016 17:09:53 GMT

Content originally posted in LPCWare by IanB on Mon Jan 05 15:20:59 MST 2015
I thought so, but I was just hoping I could get away with fewer. . .