Abstract: A power supply system and method includes a switch state controller that is operational to control a switching power converter during certain power loss conditions that cause conventional switch state controllers to have diminished or no functionality. In at least one embodiment, during certain power loss conditions, such as when an auxiliary power supply is in standby mode or when the switching power converter is not operating, a power supply for the switch state controller does not provide sufficient operating power to the switch state controller during certain power loss conditions. In at least one embodiment, during such power loss conditions power is generated for the switch state controller using sense input and/or sense output currents of the switching power converter to allow an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the switching power converter.

Abstract: A power control system includes a current sense resistor located on an output side of a switching power converter. By locating the current sense resistor on the output side of the switching power converter, the current sense resistor conducts a sense current when a control switch of the switching power converter is nonconductive. Since a duty cycle of the control switch is larger for a low input voltage than for a higher input voltage, the current sense resistor conducts current for a shorter time duration for low input voltages than for higher input voltages. Thus, the root mean square (RMS) of a sense current in the current sense resistor and, thus, power dissipation by the current sense resistor, is lower during low input voltages than power dissipation in conventionally located current sense resistors. The RMS of the sense current is approximately constant across a full range of input voltages.

Abstract: A power control system and method senses input and/or output voltages of a power supply using sense currents in order for an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the power control system. By sensing sense currents, the power control system can eliminate at least one sense resistor used in a voltage sense system. The sense current(s) can be used to provide power and sensing to the switch state controller. In at least one embodiment, the sense current(s) provide power to the switch state controller when auxiliary IC power is unavailable or diminished, such as during start-up of the IC. In at least one embodiment, the IC draws more sense current from an input of the power control system than the output of the power control system to, for example, minimize impact on the output voltage of the power supply.

Abstract: A power control system includes a current sense resistor located on an output side of a switching power converter. By locating the current sense resistor on the output side of the switching power converter, the current sense resistor conducts a sense current when a control switch of the switching power converter is nonconductive. Since a duty cycle of the control switch is larger for a low input voltage than for a higher input voltage, the current sense resistor conducts current for a shorter time duration for low input voltages than for higher input voltages. Thus, the root mean square (RMS) of a sense current in the current sense resistor and, thus, power dissipation by the current sense resistor, is lower during low input voltages than power dissipation in conventionally located current sense resistors. The RMS of the sense current is approximately constant across a full range of input voltages.

Abstract: A power control system and method senses input and/or output voltages of a power supply using sense currents in order for an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the power control system. By sensing sense currents, the power control system can eliminate at least one sense resistor used in a voltage sense system. The sense current(s) can be used to provide power and sensing to the switch state controller. In at least one embodiment, the sense current(s) provide power to the switch state controller when auxiliary IC power is unavailable or diminished, such as during start-up of the IC. In at least one embodiment, the IC draws more sense current from an input of the power control system than the output of the power control system to, for example, minimize impact on the output voltage of the power supply.

Abstract: A power supply system and method includes a switch state controller that is operational to control a switching power converter during certain power loss conditions that cause conventional switch state controllers to have diminished or no functionality. In at least one embodiment, during certain power loss conditions, such as when an auxiliary power supply is in standby mode or when the switching power converter is not operating, a power supply for the switch state controller does not provide sufficient operating power to the switch state controller during certain power loss conditions. In at least one embodiment, during such power loss conditions power is generated for the switch state controller using sense input and/or sense output currents of the switching power converter to allow an integrated circuit (IC) switch state controller to generate a control signal to control a switch of the switching power converter.