Switching regulators have negative input impedance, at least at low frequency. Before switching regulators came into such widespread use, they were mainly stand-alone units operating from a low source impedance and driving a passive load. Oscillation was rarely a problem. Now, as switching regulators become lower in cost and more widespread in application, there are many instances where switching regulators serve as both source and load. This is happening both at low power, as in distributed power systems, and at high power, in utility systems with DC links. This white paper discusses various criteria that have been developed to assure stability under these source- load conditions and gives practical suggestions of design and testing criteria to assure stability under all operating conditions. Download this white paper to learn:
• Input Filter Considerations
• L-C Filter With Damping
• Negative Resistance Load
• Relative Placement of Filter Resonance and Power Supply Bandwidth
• Power Supply with Input Filter
• Dual Nature of Filters
• Effect of Input Filter on Transfer Function
• Effect of Filter on Feedback Loop Transfer Function
• Testing Impedance
• Relative Source and Load Impedance
• Effect of Feedback Loop on Power Supple Output Impedance
• Crossover Below Output L-C Corner
• Crossover About Output L-C Corner
• Crossover Above Output L-C Corner with Under-Damped Filter
• One Supply Driving Another
• One Power Supply Driving Several-Others
Download this white paper to learn best-practices for source-load interactions. Complete the form on the right to gain access.
