I have various Z80 CPU's in my parts bin. Some are from Zilog and some are from other companies (IIRC). Some of them are hard to see the part numbers so I can't tell who made them but I'm sure they are Z80's.
Anyway, I need to build a circuit that uses the Z80 as the primary CPU (mini-computer) but I want to connect it to 3.3v devices like the propeller or other microcontrollers.
I've looked in various datasheets that I can find but none of them mention if the CPU can be powered from 3.3v. I read they can "tolerate" -0.3v to 7v on all input pins but nothing (that I can find) says they can be driven by a 3.3v power supply.
The frequency I would like to run the CPU would be the NTSC colorbust frequency of 3.57954 MHz but it could go as high as 4 MHz.
Thanks for any information.
Best Answer
The datasheet says Vcc= 5 V ±5%.
At the time the Z80 was introduced 3.3V logic was completely uncommon (if not non-existent).
Cf. this table about different logic families, typical supply voltages and year of introduction.
The Z80 dates back to the time when TTL-LS (low-power-Schottky) was common.