Utilization of a multifunctional pin combining voltage sensing and zero current detection to control a switched-mode power converter

A method of controlling a power converter, the method comprising:

• forming an inductor with a primary winding and a secondary winding;
• coupling the primary winding to a power switch of the power converter;
• coupling a resistor to the secondary winding;
• producing an estimate of an input voltage and an output voltage of the power converter using a current flowing in the resistor;
• selecting a voltage range of the input voltage of the power converter using the current flowing through the resistor;
• and
• controlling a duty cycle of the power switch employing the estimate of the input voltage and the output voltage.

A power converter, comprising:

• a power switch;
• an inductor coupled in series with the power switch, wherein the inductor includes a secondary winding;
• a resistor coupled in series with the secondary winding;
• and
• a controller including a circuit node coupled to the resistor, wherein the controller is configured to estimate a terminal voltage of the power converter by sensing a current flowing in the resistor to control a duty cycle of the power switch, wherein the controller selects a line voltage range of an input voltage to the power converter in response to the current flowing through the resistor.

A method of controlling a power converter, the method comprising:

• forming an inductor with a primary winding and a secondary winding;
• coupling the primary winding to a power switch of the power converter;
• coupling a resistor to the secondary winding;
• producing an estimate of a terminal voltage of the power converter using a current flowing in the resistor;
• controlling a duty cycle of the power switch employing the estimate of the terminal voltage;
• and
• selecting a line voltage range of an input voltage to the power converter using the current flowing through the resistor.