Abstract: A system includes an isolated converter having a power transformer with a primary winding, a secondary winding, and an auxiliary winding. The system also includes: 1) a first switch coupled to the primary winding; 2) a switch controller coupled to the first switch; and 3) a bias power regulator circuit coupled to the auxiliary winding and the switch controller. The bias power regulator circuit includes a second switch. The bias power regulator circuit is configured to provide a bias supply output voltage to the switch controller based on a first set of modes that modulate a switching frequency of the second switch and based on a second mode in which the second switch stays off.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for adaptive synchronous rectifier control. An example apparatus includes an adaptive off-time control circuit to determine a first voltage and a second voltage when a drain voltage of a switch satisfies a voltage threshold, the first voltage based on a first off-time of the switch, the second voltage based on the first off-time and a first scaling factor, determine a third voltage based on a second scaling factor and a second off-time of the switch, the second off-time after the first off-time, and determine a third off-time of the switch based on at least one of the second voltage or the third voltage. The example apparatus further includes a driver to turn off the switch for at least the third off-time after the second off-time.

Abstract: A system includes an isolated converter having a power transformer with a primary winding, a secondary winding, and an auxiliary winding. The system also includes: 1) a first switch coupled to the primary winding; 2) a switch controller coupled to the first switch; and 3) a bias power regulator circuit coupled to the auxiliary winding and the switch controller. The bias power regulator circuit includes a second switch. The bias power regulator circuit is configured to provide a bias supply output voltage to the switch controller based on a first set of modes that modulate a switching frequency of the second switch and based on a second mode in which the second switch stays off.

Abstract: A system includes an isolated converter having a power transformer with a primary winding, a secondary winding, and an auxiliary winding. The system also includes: 1) a first switch coupled to the primary winding; 2) a switch controller coupled to the first switch; and 3) a bias power regulator circuit coupled to the auxiliary winding and the switch controller. The bias power regulator circuit includes a second switch. The bias power regulator circuit is configured to provide a bias supply output voltage to the switch controller based on a first set of modes that modulate a switching frequency of the second switch and based on a second mode in which the second switch stays off.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for adaptive synchronous rectifier control. An example apparatus includes an adaptive off-time control circuit to determine a first voltage and a second voltage when a drain voltage of a switch satisfies a voltage threshold, the first voltage based on a first off-time of the switch, the second voltage based on the first off-time and a first scaling factor, determine a third voltage based on a second scaling factor and a second off-time of the switch, the second off-time after the first off-time, and determine a third off-time of the switch based on at least one of the second voltage or the third voltage. The example apparatus further includes a driver to turn off the switch for at least the third off-time after the second off-time.

Abstract: In some examples, a circuit includes an input circuit, an output circuit, an auxiliary circuit, and a balancing circuit. The input circuit comprises a primary capacitor coupled to primary windings of a transformer. The output circuit comprises a secondary capacitor coupled to secondary windings of the transformer, wherein the secondary windings are coupled to the primary windings. The auxiliary circuit comprises auxiliary windings coupled to the primary windings. The balancing circuit is coupled to the output circuit, the auxiliary circuit, and the input circuit. The balancing circuit is configured to balance a voltage across the primary capacitor with a voltage across the secondary capacitor.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for adaptive synchronous rectifier control. An example apparatus includes an adaptive off-time control circuit to determine a first voltage and a second voltage when a drain voltage of a switch satisfies a voltage threshold, the first voltage based on a first off-time of the switch, the second voltage based on the first off-time and a first scaling factor, determine a third voltage based on a second scaling factor and a second off-time of the switch, the second off-time after the first off-time, and determine a third off-time of the switch based on at least one of the second voltage or the third voltage. The example apparatus further includes a driver to turn off the switch for at least the third off-time after the second off-time.

Abstract: In an example, a circuit includes a first power switch device coupled between a voltage input and an output terminal, the first power switch device having a control input. A voltage divider circuit includes a first resistor and a second resistor. The first resistor is coupled between the voltage input and a sense node between the first resistor and the second resistor. The second resistor has a first terminal coupled to the sense node and a second terminal. A second switch device is coupled between the second terminal of the second resistor and an electrical ground terminal. A voltage clamp is coupled between the sense node and the electrical ground terminal.

Abstract: In an example, a circuit includes a first power switch device coupled between a voltage input and an output terminal, the first power switch device having a control input. A voltage divider circuit includes a first resistor and a second resistor. The first resistor is coupled between the voltage input and a sense node between the first resistor and the second resistor. The second resistor has a first terminal coupled to the sense node and a second terminal. A second switch device is coupled between the second terminal of the second resistor and an electrical ground terminal. A voltage clamp is coupled between the sense node and the electrical ground terminal.

Abstract: In some examples, a circuit includes an input circuit, an output circuit, an auxiliary circuit, and a balancing circuit. The input circuit comprises a primary capacitor coupled to primary windings of a transformer. The output circuit comprises a secondary capacitor coupled to secondary windings of the transformer, wherein the secondary windings are coupled to the primary windings. The auxiliary circuit comprises auxiliary windings coupled to the primary windings. The balancing circuit is coupled to the output circuit, the auxiliary circuit, and the input circuit. The balancing circuit is configured to balance a voltage across the primary capacitor with a voltage across the secondary capacitor.

Abstract: A system includes an isolated converter having a power transformer with a primary winding, a secondary winding, and an auxiliary winding. The system also includes: 1) a first switch coupled to the primary winding; 2) a switch controller coupled to the first switch; and 3) a bias power regulator circuit coupled to the auxiliary winding and the switch controller. The bias power regulator circuit includes a second switch. The bias power regulator circuit is configured to provide a bias supply output voltage to the switch controller based on a first set of modes that modulate a switching frequency of the second switch and based on a second mode in which the second switch stays off.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for adaptive synchronous rectifier control. An example apparatus includes an adaptive off-time control circuit to determine a first voltage and a second voltage when a drain voltage of a switch satisfies a voltage threshold, the first voltage based on a first off-time of the switch, the second voltage based on the first off-time and a first scaling factor, determine a third voltage based on a second scaling factor and a second off-time of the switch, the second off-time after the first off-time, and determine a third off-time of the switch based on at least one of the second voltage or the third voltage. The example apparatus further includes a driver to turn off the switch for at least the third off-time after the second off-time.

Abstract: A synchronous rectifier controller integrated circuit. The synchronous rectifier controller integrated circuit comprises a continuous current mode (CCM) detection circuit configured to detect CCM operation based on sensing a voltage at a pre-defined point in a rectification cycle; a multiplexer having a first reference voltage signal input, a second reference voltage signal input, an output, and a selector input coupled to the CCM detection circuit; and a gate voltage driver circuit coupled to the output of the multiplexer.

Abstract: Methods of operating switching power supplies are disclosed. A power supply has a transformer and a switch coupled to the primary side of the transformer for controlling the current flow through the primary side of the transformer. A method includes determining the output voltage of the power supply. A first minimum switching frequency is generated for driving the switch in response to the output voltage being greater than a nominal output voltage and less than a predetermined voltage. A second minimum switching frequency is generated for driving the switch in response to the output voltage being equal to or greater than the predetermined voltage, wherein the first minimum switching frequency is greater than the second minimum switching frequency.

Abstract: Methods of operating switching power supplies are disclosed. A power supply has a transformer and a switch coupled to the primary side of the transformer for controlling the current flow through the primary side of the transformer. A method includes determining the output voltage of the power supply. A first minimum switching frequency is generated for driving the switch in response to the output voltage being greater than a nominal output voltage and less than a predetermined voltage. A second minimum switching frequency is generated for driving the switch in response to the output voltage being equal to or greater than the predetermined voltage, wherein the first minimum switching frequency is greater than the second minimum switching frequency.

Abstract: A system includes control circuitry configured to provide one or more control pulses in response to a command signal, the one or more control pulses being communicated from the control circuitry to associated circuitry via a connection. A detector is configured to detect a disturbing signal that mitigates reception of the one or more control pulses via the connection. The command signal is controlled to cause the control circuitry to provide one or more additional control pulses when the disturbing signal is detected by the detector to improve a likelihood of the reception of the one or more control pulses via the connection.

Abstract: A system includes control circuitry configured to provide one or more control pulses in response to a command signal, the one or more control pulses being communicated from the control circuitry to associated circuitry via a connection. A detector is configured to detect a disturbing signal that mitigates reception of the one or more control pulses via the connection. The command signal is controlled to cause the control circuitry to provide one or more additional control pulses when the disturbing signal is detected by the detector to improve a likelihood of the reception of the one or more control pulses via the connection.