Secondary-side dynamic load detection and communication device

摘要

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.

主权项

1. A switching power converter comprising:
a transformer including a primary winding coupled to an input voltage and a secondary winding coupled to an output of the switching power converter; a power switch coupled to the primary winding of the transformer, current in the primary winding being generated responsive to the power switch being turned on and not generated responsive to the power switch being turned off; a rectifier coupled to the secondary winding of the transformer, the rectifier conducting a rectified current to the output of the switching power converter during off cycles of the power switch; a detection circuit measuring voltage across the rectifier, the detection circuit detecting a decrease in the voltage across the rectifier outside of a blanking period and generating one or more current pulses in the secondary winding of the transformer in response to detecting the voltage decrease; and a fast power-on-reset (POR) device coupled to the detection circuit, the fast POR device generating a startup signal to activate the detection circuit at an end of the blanking period.