Hey Everyone, I got a heat problem with some circuit I made and I hope you can help.
First let me give a short description of the circuit: Encoder input is decoded using LS7084 (Encoder to Counter Interface Chip), The Up/Down and Clock outputs are connected to three 74F269 (8 bit bi-directional counters) and the outputs of the counters are connected to 74HC573 latch.
The problem is that the three counters are getting quite hot (I actually measured 46 degrees Celsius). I have checked the 74F269 datasheet and found it uses 100mA Supply current, witch sounds it me like a lot. it means that each IC takes about 0.5W.
The things I'm trying to understand are: Could 0.5W make so much heat? Are those ICs suppose to get so hot? And if not, what could cause that? Why the poor 74F269 wants so much current? Could the cause be that the 74F269 are a TTL and the 74HC573 are CMOS?
Best regards, Edo Reshef