How does bi-directional level converter affect sink and source current?

Suppose I have an I/O pin on an MCU running at 3.3V and the pin has max sink or source current of 40mA.

When I connect one of these bi-directional level converters from Sparkfun to the pin:

Where each channel has this schematic:

And I have the HV side powered with 5V, how does this affect how much current I can sink or source on the 5V side of the converter?

Those cannot source any current on the high side, unless it's pulled more than a diode-drop below the low side voltage (at which point the body diode of the fet will conduct).

They are meant for data - the high side is pulled up to 5v through a 10k resistor.

When the low side is driven low, you can get approx the full sink current through it, though.

In general, if you're asking about source/sink current when using one of those, you're using the wrong tool for the job. What is your application?

No specific application, other than things like connecting serial. I was just reading the datasheet for some MCUs where they talk about the max current the pins can source and sink, and it made me wonder what I need to look out for regarding resistor values such as for limiting current and pull ups.

the current sunk when the pin is driven low is what flows through 10k across 3.3v plus what flows through 10k across 5v - 0.83mA by my calculations - so it's nothing to worry about with these.

Thanks. Your explanation in your posts clears it up for me.