| Electronics > Projects, Designs, and Technical Stuff |
| Pushing the 3.3V<->5V envelope |
| << < (3/3) |
| Chris_Walch:
You could remove all the RAM, ROM and IO chips from their sockets and measure the CPU signals. That should give you an idea of the maximum level. |
| Siwastaja:
--- Quote from: rea5245 on November 21, 2019, 04:57:19 pm ---But is it even necessary? My voltage readings suggest the 6502's outputs are 3.6V or less. If true, that should be fine for a microcontroller running at 3.6V. Or am I missing something? Do NMOS outputs peak at 0.7 * Vdd? --- End quote --- The actual output voltage is likely dependent on unit variation and operating temperature, so I'd add some series resistance to limit current into the PIC's protection diodes in case the voltage does end up even just a little bit over Vccpic+0.3V. Adding some 220ohms likely won't slow down the IO too much, but limits the current below 1mA even if the output voltage rises up to around 4.1V. |
| Navigation |
| Message Index |
| Previous page |