Abstract: A system includes a control circuit having a voltage input and a control circuit output. The control circuit produces a control voltage at the control circuit output having a magnitude inversely related to a magnitude of an input voltage at the input voltage input. A VCO has a VCO control input and a VCO clock output. The VCO control input is coupled to the control circuit output. The VCO produces a VCO clock on the VCO clock output having a frequency that is a function of the control voltage. A protection circuit has a first clock input, a second clock input, and a protection circuit output. The second clock input is coupled to the VCO clock output. The protection circuit generates a protection circuit output signal at the protection circuit output based on a difference in frequency between a clock signal at the first clock input and the VCO clock.

Abstract: In examples, a circuit comprises a transformer including first and second windings forming an isolation barrier. The circuit includes a first controller coupled to the second winding, a rectifier, and an output of the circuit, the first controller configured to generate a signal indicating a voltage on the output. The circuit comprises a second controller coupled to the first winding and switches and separated from the first controller by the isolation barrier, the second controller configured to operate the switches to have a capped, variable duty cycle, to have an uncapped, variable duty cycle, or to maintain the voltage within a hysteresis band, responsive to the signal.

Abstract: A system includes a control circuit having a voltage input and a control circuit output. The control circuit produces a control voltage at the control circuit output having a magnitude inversely related to a magnitude of an input voltage at the input voltage input. A VCO has a VCO control input and a VCO clock output. The VCO control input is coupled to the control circuit output. The VCO produces a VCO clock on the VCO clock output having a frequency that is a function of the control voltage. A protection circuit has a first clock input, a second clock input, and a protection circuit output. The second clock input is coupled to the VCO clock output. The protection circuit generates a protection circuit output signal at the protection circuit output based on a difference in frequency between a clock signal at the first clock input and the VCO clock.

Abstract: A power converter includes an isolator having a first terminal, a second terminal, a third terminal, and a fourth terminal. A first circuit has a first terminal coupled to the first terminal of the isolator and has a second terminal coupled to the second terminal of the isolator. A second circuit has a first terminal coupled to the third terminal of the isolator and has a second terminal coupled to the fourth terminal of the isolator. The second circuit includes a controller configured to transmit a control signal through the isolator to the first circuit. The control signal includes a first indication to turn on power transmission through the isolator from the first circuit to the second circuit, a second indication of a status, and a third indication to turn off power transmission.

Abstract: In some examples, an apparatus includes: a power stage having a power stage voltage input, a power stage control input, and a power stage output; a controller having a power stage control output coupled to the power stage control input, an output voltage status terminal, and a status signal input; a transformer having a primary side coil coupled to the power stage output, and a secondary side coil; a feedback voltage processor having a feedback input coupled to the secondary side coil, and a feedback output; a control message generator having a control input coupled to the secondary side coil, and a control message output; a status signal generator having first and second signal inputs coupled to respective feedback and control message outputs, and a status signal output; and a communication channel device coupled between the status signal input and output.

Abstract: A DC-to-DC converter having primary- and secondary-side circuitry separated by an isolation barrier, with a transformer and a feedback lane across the barrier, uses a dynamic function current source in its secondary-side circuitry to dynamically adjust the hysteresis threshold only at the transformer burst turn-off edge to provide enhanced immunity to transformer switching noise. An output voltage of the converter (or signal based thereon) is compared to the threshold to provide an input to a timing pulse generator that closes a switch to couple the dynamic function current source into voltage threshold setting circuitry. The dynamic function current source can reduce the threshold to a level that avoids chattering in transformer burst turn-off feedback signal caused by the noise, for a duration that can be based on lane delay of the converter and to an amplitude that can be based on the expected maximum negative amplitude of the noise.

Abstract: A DC-to-DC converter having primary- and secondary-side circuitry separated by an isolation barrier, with a transformer and a feedback lane across the barrier, uses a dynamic function current source in its secondary-side circuitry to dynamically adjust the hysteresis threshold only at the transformer burst turn-off edge to provide enhanced immunity to transformer switching noise. An output voltage of the converter (or signal based thereon) is compared to the threshold to provide an input to a timing pulse generator that closes a switch to couple the dynamic function current source into voltage threshold setting circuitry. The dynamic function current source can reduce the threshold to a level that avoids chattering in transformer burst turn-off feedback signal caused by the noise, for a duration that can be based on lane delay of the converter and to an amplitude that can be based on the expected maximum negative amplitude of the noise.

Abstract: A system includes a control circuit having a voltage input and a control circuit output. The control circuit produces a control voltage at the control circuit output having a magnitude inversely related to a magnitude of an input voltage at the input voltage input. A VCO has a VCO control input and a VCO clock output. The VCO control input is coupled to the control circuit output. The VCO produces a VCO clock on the VCO clock output having a frequency that is a function of the control voltage. A protection circuit has a first clock input, a second clock input, and a protection circuit output. The second clock input is coupled to the VCO clock output. The protection circuit generates a protection circuit output signal at the protection circuit output based on a difference in frequency between a clock signal at the first clock input and the VCO clock.

Abstract: In some examples, an apparatus includes: a power stage having a power stage voltage input, a power stage control input, and a power stage output; a controller having a power stage control output coupled to the power stage control input, an output voltage status terminal, and a status signal input; a transformer having a primary side coil coupled to the power stage output, and a secondary side coil; a feedback voltage processor having a feedback input coupled to the secondary side coil, and a feedback output; a control message generator having a control input coupled to the secondary side coil, and a control message output; a status signal generator having first and second signal inputs coupled to respective feedback and control message outputs, and a status signal output; and a communication channel device coupled between the status signal input and output.