Operation mode determination circuit and method thereof

An operation mode determination circuit, configured to operably sense a setting resistance between a setting node and a reference voltage or a ground to determine an operation mode, comprising:

• a pull-up power circuit, configured to operably generate a pull-up power onto the setting node, and adjust the pull-up power to be at a first power level in an operation mode detection procedure, wherein the pull-up power circuit triggers an low power detach detection procedure after a first predetermined time period from when the operation mode detection procedure starts, and adjusts the pull-up power to be at a second power level in the low power detach detection procedure, wherein the second power level is less than the first power level to an extent that when an electrolytic substance exists and is coupled to the setting node, an electrolysis effect of the electrolytic substance is negligible;
• a voltage sensing circuit, configured to operably sense a voltage level of the setting node to determine an operation mode in the operation mode detection procedure;
• and
• a floating detection circuit which includes a comparison circuit for comparing the voltage level of the setting node to a first voltage threshold in the low power detach detection procedure, the floating detection circuit being configured to operably trigger the operation mode detection procedure when the voltage level of the setting node is higher than the first voltage threshold.