METHOD OF FORMING A POWER SUPPLY CONTROLLER AND STRUCTURE THEREFOR

摘要

In one embodiment, a power supply controller may be configured to form a status signal that is representative of a secondary current by substantially removing a primary magnetization component from a primary current signal and to use the status signal to form a first signal that is representative of a delivered output power, and configured to adjust an on-time of one of a first or second switch responsively to the delivered output power.

主权项

1. A power supply controller comprising:
a control circuit configured to form at least one switching control signal to control first and second switches to form a primary current through a resonant circuit to regulate an output voltage to a load from an input voltage and form a load current for the load; a first circuit configured to receive a first signal that is representative of a value of the primary current and to receive a second signal that is representative of the input voltage and responsively form a control signal having a value that is proportional to a delivered output power; a feedback circuit configured to receive a signal that is representative of the output voltage and form a feedback signal that is representative of the output voltage; a first compensation circuit configured to decrease a value of the feedback signal proportional to a value of the input voltage responsively to enabling the first switch; the power supply controller configured to adjust one of the first signal proportionally to the control signal to form a compensated current sense signal or to adjust the feedback signal proportionally to the control signal to form a compensated feedback signal; and the control circuit configured to terminate an ON-time of the first switch responsively to one of the compensated current sense signal approximately equaling the feedback signal or the compensated feedback signal approximately equaling the first signal.