摘要 |
<p>A power supply control circuit which enables the constant current (CC) and constant voltage (CV) feedback loops to be compensated independent of each other. In accordance with the invention, an inner feedback loop (202) has been added which is local to the output stage (108) so as to allow a constant voltage (CV) feedback loop (112-120) to see a closed loop transfer function of the inner feedback loop (202) that mimics an output for a constant voltage (CV) preferred output stage even though a constant current (CC) preferred output stage is used. As a result, load impedance (118) variations that would have affected the loop gain of the constant voltage (CV) feedback loop (112-120) affect the loop gain of the inner feedback loop (202) only. The inner feedback loop (202) is disposed such that it is automatically disabled by the constant current (CC) feedback loop (102-110) when the power supply enters the constant current (CC) mode and hence allows the constant current (CC) and constant voltage (CV) modes to be decoupled from one another. The inner feedback loop (202) of the invention may also be disposed within the constant current (CC) feedback loop so as to allow independent mode operation for a constant voltage (CV) preferred output stage (108). <IMAGE></p> |