Stability Testing Of Multi-Loop Converters
Measurement of loop gain and loop phase shift versus frequency is generally
possible with single output power supplies or multiple output supplies where
each output is independently regulated. These measurements are necessary to
determine the phase and gain margins and insure stability of the feedback
loop. Measurement requires access to a point where the loop is confined to
a single path. Such a point does not exist in many low-cost computer power
supplies, and these supplies constitute the numerical majority of power
supplies manufactured today. This paper presents techniques for overcoming
this obstacle and obtaining loop data even where a single signal path is
not accessible.
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