I'm fairly new to electronics, so forgive me if this is a stupid question. I'm looking to interface two systems, one of which is a 3.3V microcontroller, and the other a system running on an unknown voltage (almost guaranteed to be <5V though). For this I wanted to use a dual-supply level-shifter, and the TXB0108 looks like a good fit, especially with the breadboard-friendly breakout board. I need to be careful about controlling the input and output currents, though, and I'm a little unsure as to how to do that. My requirement is that the microcontroller side be <20mA, and the other side be <8mA. Can I just put a series resistor on each of the lines? As I understand it that would reduce the slew rate of the signal, which I definitely don't want. Or can I just put a resistor on VCC to reduce the amount of current that the level-shifter can sink? And according to ohm's law, wouldn't each of these solutions drop a certain amount of voltage over the resistor, leading to a voltage level less than VCC? So I guess in short, the question is, how do I limit the amount of current flowing through the data lines of a level-shifter?
Thanks in advance,