# Can power specs be used without extending the margin to account for losses?

Looking generally at the 74FCT family, I saw that it's power pin should be held at $5V \pm 5 \%$ to be in specs. From my understanding, $\pm5\%$ power supplies are widely available, but are the top of the cheaply available ones.

Considering a reasonable (devoted layer) ground and power plane on a PCB, would it be reasonable to power a PCB from a 5% precise supply (at 5V) ? Or would the losses and parasitics be too much of a problem ?

If I needed a more precise voltage, how should I tackle that ?

• would it be reasonable to power from a ±5% supply? ... please clarify what you are asking – jsotola Feb 17 '18 at 16:49
• What would you need me to add ? – Sachiko.Shinozaki Feb 17 '18 at 16:50
• Yes it would be reasonable to use a +/- 5% supply for a +/- 5% IC. You can double-check the actual voltage with a volt meter if you like. So that you can feel more comfortable after you build the circuit. – mkeith Feb 17 '18 at 16:56
• @Sachiko.Shinozaki, i was trying to figure out what you mean by "reasonable" ... i read your post several times, and i think that i understand. ... you may run into problems if you end up with a -5% power supply ... the voltage at the "far end" of the board may drop below the -5% level ........ find a power supply with an adjustable output – jsotola Feb 17 '18 at 17:07