Abstract: A power converter circuit includes a transformer. The transformer includes a primary winding and a secondary winding. A primary circuit is coupled to the primary winding. A secondary circuit is coupled to the secondary winding. The primary circuit and the secondary circuit are referenced to different ground voltage potentials that may vary with respect to each other. During operation, the primary circuit controls input of energy to the primary winding of the transformer. The secondary circuit receives the energy through the secondary winding and uses it to produce an output voltage to power a load. The secondary circuit receives and/or generates state information at one of multiple different levels. The secondary circuit controls a flow of current through the secondary winding to convey the state information as feedback to the primary circuit. The primary circuit analyzes a voltage at a node of the primary winding to receive the feedback.

Abstract: In some examples, a device includes level-shifter circuitry and biasing circuitry including at least four diodes, wherein each diode of the at least four diodes is electrically connected in series. The biasing circuitry further includes push-pull circuitry electrically connected to at least two diodes of the at least four diodes and configured to generate an intermediate voltage signal. The biasing circuitry is configured to deliver a high-side biasing signal to the level-shifter circuitry based on the intermediate voltage signal and a high-side voltage signal from the at least four diodes. The biasing circuitry is further configured to deliver a low-side biasing signal to the level-shifter circuitry based on the intermediate voltage signal and a low-side voltage signal from the at least four diodes.

Abstract: A power converter circuit includes a transformer. The transformer includes a primary winding and a secondary winding. A primary circuit is coupled to the primary winding. A secondary circuit is coupled to the secondary winding. The primary circuit and the secondary circuit are referenced to different ground voltage potentials that may vary with respect to each other. During operation, the primary circuit controls input of energy to the primary winding of the transformer. The secondary circuit receives the energy through the secondary winding and uses it to produce an output voltage to power a load. The secondary circuit receives and/or generates state information at one of multiple different levels. The secondary circuit controls a flow of current through the secondary winding to convey the state information as feedback to the primary circuit. The primary circuit analyzes a voltage at a node of the primary winding to receive the feedback.

Abstract: A power converter with an isolated topology may include a primary side and a secondary side. The secondary side includes a self-powered synchronous rectifier. The synchronous rectifier includes a synchronous rectifier transistor having at least a drain and a gate, a voltage regulator having at least an input that is coupled to the drain of the synchronous rectifier transistor, and an auxiliary transistor having at least a drain that is coupled to the drain of the synchronous rectifier transistor. The auxiliary transistor is on a same die as the synchronous rectifier transistor. The synchronous rectifier also includes a clamping device having at least an output that is coupled to the gate of the auxiliary transistor, and a gate driver circuit having at least: a power supply input that is coupled to the output of the voltage regulator, and an output that is coupled to a gate of the synchronous rectifier transistor.

Abstract: A phase current estimator for a switching power converter includes analog circuitry for generating a phase current estimate error by comparing a phase current of the switching power converter to an analog representation of an estimate of the phase current, the phase current having a sawtooth or triangular waveform. The phase current estimator further includes digital circuitry for revising the phase current estimate based on the phase current estimate error and a plurality of parameters associated with operation of the switching power converter, so that the phase current estimate tracks the sawtooth or triangular waveform of the phase current.

Abstract: A power converter circuit includes a transformer. The transformer includes a primary winding and a secondary winding. The power converter circuit uses energy conveyed from the primary winding of the transformer through the secondary winding of the transformer to produce an output voltage to power a load. Control circuitry of the power converter circuit initiates conveying a portion of the received energy through the secondary winding back through the primary winding to control a magnitude of the output voltage. For example, if the magnitude of the output voltage is above a desired setpoint value, such as due to a transient load condition or change in the setpoint of the output voltage, the control circuitry reduces the magnitude of the output voltage by conveying excess energy from an output capacitor (that stores the output voltage) through the secondary winding to the primary winding.

Abstract: Circuits that provide an auxiliary power supply on the secondary side of an isolated switched-mode power converter are described. Such an auxiliary supply may be used to provide power to a secondary side controller or to other circuitry in the secondary side of the power converter. During at least a start-up phase of the power converter, the secondary side auxiliary power supply is supplied power by use of a self-starting primary side driver that operates autonomously until the secondary side controller is fully operational. Circuits and methods for such a self-starting primary side driver are provided. The techniques disclosed provide for a secondary side auxiliary power supply that uses minimal additional circuitry.

Abstract: A power converter with an isolated topology may include a primary side and a secondary side. The secondary side includes a self-powered synchronous rectifier. The synchronous rectifier includes a synchronous rectifier transistor having at least a drain and a gate, a voltage regulator having at least an input that is coupled to the drain of the synchronous rectifier transistor, and an auxiliary transistor having at least a drain that is coupled to the drain of the synchronous rectifier transistor. The auxiliary transistor is on a same die as the synchronous rectifier transistor. The synchronous rectifier also includes a clamping device having at least an output that is coupled to the gate of the auxiliary transistor, and a gate driver circuit having at least: a power supply input that is coupled to the output of the voltage regulator, and an output that is coupled to a gate of the synchronous rectifier transistor.

Abstract: A power converter with an isolated topology may include a power transistor, a sense transistor, and a read-out circuit. The sense transistor may be arranged in a current mirror configuration with the power transistor such that the gate terminal of the sense transistor is coupled to the gate terminal of the power transistor and the first drain/source terminal of the sense transistor is coupled to the first drain/source terminal of the power transistor. The read-out circuit may be coupled to the second drain/source terminal of the power transistor and the second drain source/terminal of the sense transistor. The read-out circuit may be arranged to cause a voltage at the second drain/source terminal of the sense transistor to be substantially the same as a voltage at the second drain/source terminal of the power transistor.

Abstract: Circuits that provide an auxiliary power supply on the secondary side of an isolated switched-mode power converter are described. Such an auxiliary supply may be used to provide power to a secondary side controller or to other circuitry in the secondary side of the power converter. During at least a start-up phase of the power converter, the secondary side auxiliary power supply is supplied power by use of a self-starting primary side driver that operates autonomously until the secondary side controller is fully operational. Circuits and methods for such a self-starting primary side driver are provided. The techniques disclosed provide for a secondary side auxiliary power supply that uses minimal additional circuitry.

Abstract: A power converter circuit includes a transformer. The transformer includes a primary winding and a secondary winding. A primary circuit is coupled to the primary winding. A secondary circuit is coupled to the secondary winding. The primary circuit and the secondary circuit are referenced to different ground voltage potentials that may vary with respect to each other. During operation, the primary circuit controls input of energy to the primary winding of the transformer. The secondary circuit receives the energy through the secondary winding and uses it to produce an output voltage to power a load. The secondary circuit receives and/or generates state information at one of multiple different levels. The secondary circuit controls a flow of current through the secondary winding to convey the state information as feedback to the primary circuit. The primary circuit analyzes a voltage at a node of the primary winding to receive the feedback.

Abstract: A power converter circuit includes a transformer. The transformer includes a primary winding and a secondary winding. A primary circuit is coupled to the primary winding. A secondary circuit is coupled to the secondary winding. The primary circuit and the secondary circuit are referenced to different ground voltage potentials that may vary with respect to each other. During operation, the primary circuit controls input of energy to the primary winding of the transformer. The secondary circuit receives the energy through the secondary winding and uses it to produce an output voltage to power a load. The secondary circuit receives and/or generates state information at one of multiple different levels. The secondary circuit controls a flow of current through the secondary winding to convey the state information as feedback to the primary circuit. The primary circuit analyzes a voltage at a node of the primary winding to receive the feedback.

Abstract: A power converter circuit includes a transformer. The transformer includes a primary winding and a secondary winding. A primary circuit is coupled to the primary winding. A secondary circuit is coupled to the secondary winding. The primary circuit and the secondary circuit are referenced to different ground voltage potentials that may vary with respect to each other. During operation, the primary circuit controls input of energy to the primary winding of the transformer. The secondary circuit receives the energy through the secondary winding and uses it to produce an output voltage to power a load. The secondary circuit receives and/or generates state information at one of multiple different levels. The secondary circuit controls a flow of current through the secondary winding to convey the state information as feedback to the primary circuit. The primary circuit analyzes a voltage at a node of the primary winding to receive the feedback.

Abstract: A power converter with an isolated topology may include a primary side and a secondary side. The secondary side includes a self-powered synchronous rectifier. The synchronous rectifier includes a synchronous rectifier transistor having at least a drain and a gate, a voltage regulator having at least an input that is coupled to the drain of the synchronous rectifier transistor, and an auxiliary transistor having at least a drain that is coupled to the drain of the synchronous rectifier transistor. The auxiliary transistor is on a same die as the synchronous rectifier transistor. The synchronous rectifier also includes a clamping device having at least an output that is coupled to the gate of the auxiliary transistor, and a gate driver circuit having at least: a power supply input that is coupled to the output of the voltage regulator, and an output that is coupled to a gate of the synchronous rectifier transistor.

Abstract: In accordance with an embodiment, switch driver includes a first switch driver configured to be coupled to a control node of a first switch, a second driver configured to be coupled to a control node of a second switch, and a first terminal and a second terminal configured to be couple to a boot capacitor. The first terminal is coupled between a boot input of the first switch driver and the second terminal is configured to be coupled to outputs of the first switch and the second switch. The switch driver further includes a voltage measurement circuit coupled to the first terminal and the second terminal, and a control circuit configured to activate the second switch driver when the voltage measurement circuit indicates that a voltage across boot capacitor is below a first threshold.

Abstract: A power stage of a voltage regulator includes a first switch for connecting a load to a supply voltage in a first switching state of the power stage, a second switch for connecting the load to ground in a second switching state of the power stage and driver circuitry for setting the power stage in the first switching state, the second switching state or a non-switching state in which both switches are off responsive to a switching control signal received by the power stage. A power management unit moves the power stage from a nominal power mode to a first low power mode if the power stage is in the non-switching state for a predetermined time period.

Abstract: In accordance with an embodiment, switch driver includes a first switch driver configured to be coupled to a control node of a first switch, a second driver configured to be coupled to a control node of a second switch, and a first terminal and a second terminal configured to be couple to a boot capacitor. The first terminal is coupled between a boot input of the first switch driver and the second terminal is configured to be coupled to outputs of the first switch and the second switch. The switch driver further includes a voltage measurement circuit coupled to the first terminal and the second terminal, and a control circuit configured to activate the second switch driver when the voltage measurement circuit indicates that a voltage across boot capacitor is below a first threshold.

Abstract: A phase current estimator for a switching power converter includes analog circuitry for generating a phase current estimate error by comparing a phase current of the switching power converter to an analog representation of an estimate of the phase current, the phase current having a sawtooth or triangular waveform. The phase current estimator further includes digital circuitry for revising the phase current estimate based on the phase current estimate error and a plurality of parameters associated with operation of the switching power converter, so that the phase current estimate tracks the sawtooth or triangular waveform of the phase current.

Abstract: A power converter with an isolated topology may include a primary side and a secondary side. The secondary side includes a self-powered synchronous rectifier. The synchronous rectifier includes a synchronous rectifier transistor having at least a drain and a gate, a voltage regulator having at least an input that is coupled to the drain of the synchronous rectifier transistor, and an auxiliary transistor having at least a drain that is coupled to the drain of the synchronous rectifier transistor. The auxiliary transistor is on a same die as the synchronous rectifier transistor. The synchronous rectifier also includes a clamping device having at least an output that is coupled to the gate of the auxiliary transistor, and a gate driver circuit having at least: a power supply input that is coupled to the output of the voltage regulator, and an output that is coupled to a gate of the synchronous rectifier transistor.

Abstract: In one example, a method includes receiving a first differential signal including a first voltage signal and a second voltage signal, wherein the first differential signal includes a first common mode voltage; receiving a second common mode voltage. The method further includes determining, by a circuit, a second differential signal including a third voltage signal and a fourth voltage signal, wherein a difference between the third voltage signal and the fourth voltage signal is based on a difference between the first voltage signal and the second voltage signal, wherein the second differential signal includes the second common mode voltage. The method further includes outputting, substantially continuously, the second differential signal.