Abstract: A switching power converter may include a power switch coupled to a primary winding of a transformer, and a primary controller configured to turn on and off the power switch, a synchronous rectifier switch coupled to a secondary winding of a transformer, and a synchronous rectifier controller configured to turn on and off the synchronous rectifier switch. The synchronous rectifier controller may monitor a voltage across the synchronous rectifier switch. The synchronous rectifier controller may determine a period of a resonant oscillation of the voltage across the synchronous rectifier switch following at least one cycling off of the synchronous rectifier switch. The synchronous rectifier controller may adjust the minimum off-time period for the synchronous rectifier switch based on the period of the resonant oscillation. The synchronous rectifier controller may adaptively adjust a minimum off-time period for the synchronous rectifier switch.

Abstract: A startup circuit is provided for establishing the Vcc voltage level of a switching power converter. The startup circuit uses a switch controller and path switching transistor to provide a two-stage Vcc capacitor charging that reduces startup time while avoiding short circuit damage through the alternate usage of a high impedance charging path and a low-impedance charging path.

Abstract: A power switch transistor for a switching power converter is maintained on during a re-startup period by a zener breakdown voltage following a fault condition for the switching power converter. A source voltage from the power switch transistor is used to charge a VCC capacitor that stores a power supply voltage for a controller for the switching power converter.

Abstract: A line ripple compensation technique is provided for a switching power converter operating in both a pulse frequency mode of operation and a pulse width modulation mode of operation.

Abstract: Systems, devices, and methods are provided to enable power converters to use two or more sensing elements to reliably detect a short circuit (or soft-short circuit) existing in the power converter and distinguish these conditions from other operating conditions, such as low voltage conditions or normal operating conditions. The disclosed embodiments enable the accurate detection of fault conditions, such as short circuits or soft short conditions, using a number of sensing elements, such as sense resistors and the inherent resistance of switching devices, while preventing the detection of false positives due to other factors such as low input voltage.

Abstract: A method for estimating an output voltage of a power converter comprises sensing a voltage waveform representative of the output voltage; and detecting a first gap and a second gap. The first gap is between a time when the sensed voltage waveform crosses a first voltage reference and a time when the sensed voltage waveform crosses a second voltage reference at a voltage offset below the first voltage reference. The second gap is between a time when the sensed voltage waveform crosses a third voltage reference and a time when the sensed voltage waveform crosses the second voltage reference, the third voltage referenced at a predetermined voltage above the second voltage reference. Responsive to the first gap exceeding a threshold, a tracking error is computed based on the first gap; and responsive to the first gap not exceeding the threshold, the tracking error is computed based on the second gap.

Abstract: A flyback converter is provided with a controller that is configured to analyze the reflected feedback voltage waveforms to determine the presence of a ground connection fault for the auxiliary winding.

Abstract: A flyback converter is provided with a synchronous rectifier (SR) controller including a pulse linear regulator (PLR) charging path and an LDO charging path. The SR controller is configured to monitor the switching period and/or duty cycle of a power switch in the flyback converter to select between the PLR and LDO charging paths.

Abstract: An adaptive valley mode switching power converter is provided that switches on a power switch within valley periods of a resonant voltage oscillation for the power switch. Each valley period is determined with regard to a valley threshold voltage.

Abstract: A flyback converter is provided with a synchronous rectifier (SR) controller including a pulse linear regulator (PLR) charging path and an LDO charging path. The SR controller is configured to monitor the switching period and/or duty cycle of a power switch in the flyback converter to select between the PLR and LDO charging paths.

Abstract: A switching power converter may include a power switch coupled to a primary winding of a transformer, and a primary controller configured to turn on and off the power switch, a synchronous rectifier switch coupled to a secondary winding of a transformer, and a synchronous rectifier controller configured to turn on and off the synchronous rectifier switch. The synchronous rectifier controller may monitor a voltage across the synchronous rectifier switch. The synchronous rectifier controller may detect a fault condition responsive to the voltage reaching a turn-off voltage threshold before a minimum on-time timer expires. The synchronous rectifier controller may detect a fault condition responsive to the synchronous rectifier switch being turned off at the same time, immediately after, or within a timing guardband after the minimum on-time timer expires. The synchronous rectifier controller may adaptively increase a minimum off-time period for the synchronous rectifier switch.

Abstract: A flyback converter is provided with a controller that is configured to analyze the reflected feedback voltage waveforms to determine the presence of a ground connection fault for the auxiliary winding.

Abstract: A switching power converter provides regulated voltage to a load. The switching power converter comprises a transformer including a primary winding coupled to an input voltage and a secondary winding coupled to an output of the switching power converter. The switching power converter further comprises a power switch coupled to the primary winding and a rectifier coupled to the secondary winding. Current is generated in the primary winding responsive to the power switch being turned on and not generated responsive to the power switch being turned off. A detection circuit measures a voltage across the rectifier. If the detection circuit detects a decrease in the voltage across the rectifier outside of a blanking period, the detection circuit generates a current pulse in the secondary winding of the transformer.

Abstract: A switching power converter provides regulated voltage to a load. The switching power converter comprises a transformer including a primary winding coupled to an input voltage and a secondary winding coupled to an output of the switching power converter. The switching power converter further comprises a power switch coupled to the primary winding and a rectifier coupled to the secondary winding. Current is generated in the primary winding responsive to the power switch being turned on and not generated responsive to the power switch being turned off. A detection circuit measures a voltage across the rectifier. If the detection circuit detects a decrease in the voltage across the rectifier outside of a blanking period, the detection circuit generates a current pulse in the secondary winding of the transformer.

Abstract: A switching power converter may include a power switch coupled to a primary winding of a transformer, and a primary controller configured to turn on and off the power switch, a synchronous rectifier switch coupled to a secondary winding of a transformer, and a synchronous rectifier controller configured to turn on and off the synchronous rectifier switch. The synchronous rectifier controller may monitor a voltage across the synchronous rectifier switch. The synchronous rectifier controller may detect a fault condition responsive to the voltage reaching a turn-off voltage threshold before a minimum on-time timer expires. The synchronous rectifier controller may detect a fault condition responsive to the synchronous rectifier switch being turned off at the same time, immediately after, or within a timing guardband after the minimum on-time timer expires. The synchronous rectifier controller may adaptively increase a minimum off-time period for the synchronous rectifier switch.

Abstract: A flyback converter is provided that includes a base driver for driving a base current into a base of a BJT power switch. The base driver is controlled so as to adaptively vary the base current across at least some of the pulses.

Abstract: A switching power converter is provided that detects an activity signal generated in response to load activity using an adaptively-declining threshold.

Abstract: A two-terminal device that is configured to respond to a voltage modulation of an input signal received through the two terminals by triggering an action. The two-terminal device is further configured to verify a result of the triggered action by modulating a current driven through the two termi+6nals.

Abstract: A switching power converter provides regulated voltage to a load. The switching power converter comprises a transformer including a primary winding coupled to an input voltage and a secondary winding coupled to an output of the switching power converter. The switching power converter further comprises a power switch coupled to the primary winding and a rectifier coupled to the secondary winding. Current is generated in the primary winding responsive to the power switch being turned on and not generated responsive to the power switch being turned off. A detection circuit measures a voltage across the rectifier. If the detection circuit detects a decrease in the voltage across the rectifier outside of a blanking period, the detection circuit generates a current pulse in the secondary winding of the transformer. A fast power-on-reset device generates a startup signal to activate the detection circuit at an end of the blanking period.

Abstract: The embodiments herein describe a switched mode power converter. In particular, the embodiments herein disclose techniques for reducing power consumption of a synchronous rectifier controller of the switched mode power converter. The switched mode power converter includes a plurality of circuit components that control operation of a synchronous rectifier included in the switched mode power converter. One or more of the circuit components may be disabled to reduce power consumption.