Energy conversion architecture with secondary side control delivered across transformer element

摘要

A switched mode power converter is configured having predominate secondary side control. A primary side driving circuit is configured as a responsive state machine the output of which is input as the driving signal for a main switch. An output voltage, current or power is sensed and the secondary side controller compares the sensed output characteristic with a predefined reference. The comparison results in an error that signifies an amount that the output is out of regulation. The secondary side controller drives a secondary side switch to generate a voltage pulse across the secondary winding. The voltage pulse has a pulse width that represents the amount of error in the output characteristic. The voltage pulse is transmitted across the transformer and received by the primary side driving circuit, which generates a driving signal modulated according to the voltage pulse and drives the main switch to regulate the output characteristic.

主权项

1. A method of controlling a switching mode power converter comprising:
a. configuring a switching mode power converter comprising a transformer, an output circuit coupled to a secondary winding of the transformer, a first switch coupled to a primary winding of the transformer and a state machine coupled to the first switch, wherein the output circuit comprises a second switch coupled to the secondary winding of the transformer and a controller coupled to the second switch; b. measuring an output characteristic of the output circuit; c. generating a second switch driving signal by the controller and applying the second switch driving signal to the second switch, wherein the second switch driving signal is modulated based on the measured output characteristic, and applying the second switch driving signal to the second switch results in a first voltage pulse across the secondary winding, the first voltage pulse comprising a pulse width that corresponds to a magnitude of an out of regulation output characteristic; d. transmitting the first voltage pulse through the transformer and inputting a second voltage pulse proportional to the first voltage pulse across the secondary winding to the state machine; e. generating a first switch driving signal by the state machine, wherein the first switch driving signal is modulated according to the pulse width; and g. driving the first switch using the first switch driving signal to regulate the output characteristic.