Electronic circuit control element with tap element

A control element for use in a power supply, the control element comprising:

• a first terminal to be coupled to receive a feedback signal of the power supply;
• a power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) having a drain terminal, a source terminal, a control terminal, and a tap terminal, wherein the power MOSFET is to be coupled to an energy transfer element of the power supply to control a transfer of energy across the energy transfer element, and wherein a voltage at the tap terminal is proportional to and less than a voltage at the drain terminal when the voltage at the drain terminal is less than a pinch off voltage;
• and
• a pulse width modulator (PWM) circuit coupled to provide the control terminal of the power MOSFET with a control signal to switch the power MOSFET on and off in response to the feedback signal, wherein PWM circuit includes a line sensor coupled to receive the voltage at the tap terminal, and wherein the PWM circuit is further configured to stop switching the power MOSFET when a line voltage of the power supply drops below a first voltage level as indicated by the voltage at the tap terminal.

A control element for use in a power supply, the control element comprising:

• a first terminal to be coupled to receive a feedback signal of the power supply;
• a power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) having a drain terminal, a source terminal, a control terminal, and a tap terminal, wherein the power MOSFET is to be coupled to an energy transfer element of the power supply to control a transfer of energy across the energy transfer element, and wherein a voltage at the tap terminal is less than a voltage at the drain terminal and proportional to a current flowing through the power MOSFET between the drain and source terminals when the voltage at the drain terminal is less than a pinch off voltage;
• and
• a pulse width modulator (PWM) circuit coupled to provide the control terminal of the power MOSFET with a control signal to switch the power MOSFET on and off in response to the feedback signal, wherein the PWM circuit is coupled to receive the voltage at the tap terminal and is further configured to turn off the power MOSFET when the current flowing through the power MOSFET reaches a current limit as indicated by the voltage at the tap terminal.