6581/8580 chip getting hot

[MisterCharlie]

Hi,

I'm building an AVR version of the MIDIBOX SID, and I managed to fit 4 SIDs on the same PCB, controlled by an ATmega164P. The whole thing does work, but I'm worried about the chips getting hot. As I plug the thing on DC, my 7805, who feeds 5V to 4 SIDs, gets really hot like it was sourcing 1amp... and the SIDs themselves get hot too.

I know the original chips in the C64 where fitted with thermal paste and they draw 100mA, but I would like to know if any of you who have a successful SID working could tell me if they really do get hot (like touching it kinda hurts you).

Thanks a bunch.

[Mu-Tron]

I know the original chips in the C64 where fitted with thermal paste...

Of the 2 old breadbox C64s I've cannibalised chips from, only the VIC-II chip had any kind of thermal paste and heatsink on it. Not sure about the 8580 in the newer 64s, or the finished build, but it would suggest that the SIDs shouldn't get too hot.

[nILS]

SIDs do have a tendency to get pretty warm (you should at all times be able to keep your finger on it). If it gets hotter than that there's possibly sth wrong. Check the wiring, voltages, ... If that doesn't bring solve it - add a heatsink.

[fussylizard]

I just pulled a 6581 out of my ancient C=128 and it had thermal paste and a connection to the overall heat "shield" that goes across the whole board.  I tested the SID in my MB-6582 I'm building and it was getting pretty warm.  Voltages all tested out so I will probably add a heat sink to it unless the 6582s run much cooler.

I just checked my C=64C and it also has the heat shield with thermal paste to the SID.

HTH,

C

[MisterCharlie]

thanks for the replies guys...

well looks like I'm gonna sink everythink up. when you look at it, 100mA @ 5V is still half a watt... which can get pretty hot. I got 4.96V out of the Regulator...