The product in question is this: https://www.sparkfun.com/products/12009
My question is - can I remove the 10k pull-ups, as I wish to logic level shift but not using current sinking. I will be push-pulling logic levels from a 5V schmitt trigger and wish to down-convert the logic levels to the Raspberry Pi’s 3.3v GPIOs. I know the resistors can be changed to e.g. 1k for a stronger pull-up, but can they be removed entirely?
Thanks.
You could try, but I’m pretty sure that the board won’t work without them.
If you are going from a 5v source to a 3.3v level input, just use a resistor divider. It’s cheaper and easier.
/mike
Ok great. Another alternative being a 3.3V (or 3.6V?)Zenner diode hooked up in reverse to GND… ICs that could be used are for example the 74LVC245 or a 74HC245 hooked up to 3.3v…
Finally, I was also told to look into a TXS0108E based shifter, as afaik that does not contain any pull-ups. These are my options for now. Any feedback would be most welcome.