Reconstruction pulse shape integrity in feedback control environment

摘要

A switched mode power converter includes a closed loop feedback control mechanism for regulating an output characteristic and a resonant type circuit for inclusion of resonant energy delivery. The characteristic impedance of the resonant type circuit is modified from an optimal energy transfer configuration to one that dampens fluctuations in a feedback signal used by the closed loop feedback mechanism. The modified characteristic impedance functions to dampen those fluctuations in the feedback signal resulting from leakage inductance energy provided by the resonant type circuit.

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 main switch coupled to a primary winding of the transformer, a controller coupled to the main switch, a feedback circuit including an auxiliary winding magnetically coupled to the secondary winding, and a resonant type circuit coupled to the primary winding to form a resonant tank, wherein the resonant type circuit comprises a pair of capacitors configured with a capacitance ratio and a resistive element, further wherein the resonant type circuit further comprises a shape generating circuit configured to shape the feedback signal to have a back end that is substantially linear; b. configuring the capacitance ratio and the resistive element in the resonant tank to have a characteristic impedance that dampens fluctuations in a feedback signal received from the output circuit by the controller via the auxiliary winding and shapes the feedback signal to have the back end that is substantially linear; and c. generating a driving signal according to the received feedback signal; and d. driving the main switch using the driving signal to regulate an output characteristic.