02-13-2019, 09:14 AM
I was thinking about this again today, so I looked up the datasheet of the MCP3021. It should be able to take 5V as its VDD. That means, in theory, that you wouldn't need the voltage devider resistors R1 and R2 to drop the battery voltage to the 3.3v range. I think that you could run the chip at 5V and then use the battery voltage as a direct input. You could also, maybe, use a different voltage regulator to drop the 5V input down to 4.5V or so to use as VDD.
The only issue I see here is that the SDA line will be 0-3.3V. The datasheet says that the minimum high-level input should be 0.7VDD. If you run the chip's VDD at 5V, that would be (0.7 x 5) 3.5V. 3.3V would be under the minimum. I'm guessing it would still work, because the maximum low-level input is 0.3VDD. Anyway, it could be worth a try.
The only issue I see here is that the SDA line will be 0-3.3V. The datasheet says that the minimum high-level input should be 0.7VDD. If you run the chip's VDD at 5V, that would be (0.7 x 5) 3.5V. 3.3V would be under the minimum. I'm guessing it would still work, because the maximum low-level input is 0.3VDD. Anyway, it could be worth a try.
Card Fighters' Clash 2 English Translation ( http://cfc2english.blogspot.com/ )
Neo Geo Pocket Flash Cart and Linker Project ( http://www.flashmasta.com/ )
Avatar art thanks to Trev-Mun ( http://trevmun.deviantart.com/ )
Neo Geo Pocket Flash Cart and Linker Project ( http://www.flashmasta.com/ )
Avatar art thanks to Trev-Mun ( http://trevmun.deviantart.com/ )