loose-electron
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Best Design Tool = Capable Designers
Posts: 1638
San Diego California
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There is no "divine voltage" for power supplies on digital circuits.
RTL and discrete ECL of 1960's era was done at 12 and 15V supplies, and then was transferred over to -5.2 supplies (ECL) for integrate (Motorola 10,000 series MECL) and the 7400 seriees of TTL was done mostly for 5V, which allowed enough headroom for bipolar logic.
If I remember correctly 4000 series CMOS started at 5V in order to be plug compatible with 7400 TTL.
From there CMOS transistors started shrinking and the voltages had to reduce to keep the transistors from being burned out. (Vgs of gate oxides, and Vds punchthrough)
Digital power for logic exists at 5V, 3.3, 2.8, 2.5, 1.8, 1.2 and 0.8 volts.
I am probably forgetting a few, but those are the ones immediatly remembered.
Jerry
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