General questions about Hardware.

[urbanze]

1-) What is the impedance of the ADC? I did not find the datasheet, I just found "Input Leakage Current" and some places say it's relevant, what's this? (I'm having trouble reading low voltages with >100% error).

2-) Some peoples say that the current per pin is ~12mA, however in the datasheet it says "Maximum output drive capability = 40mA", that value is of the individual pins, or totals, or what? What current do the pins hold?

3-) Some MCU has current SINK greater than SOURCE, however again, I did not find in the datasheet. Does the ESP32 have larger SINK current?

4-) The value read by the internal temperature sensor is the internal temperature of the ESP32 or what? I put a thermometer in the metal housing of the ESP32 and the temperature was far from equal.