Measuring Phase Margin, Measure the Phase Margin of Power Supply Control Loops

Focus:

This two-page application brief defines phase margin and describes a technique for measuring phase and gain margin of a power-supply control loop. It shows sample measurements taken with Lecroy’s Waverunner oscilloscope, which has digital filter and power measurement features. The brief gives tips on reducing the effects of noise on measurement accuracy through averaging and filtering, cautions against overdriving the loop, and advises designers to verify phase-margin measurements by measuring power-supply response to a step change in the load.

What you’ll learn:

• How to measure phase and gain margin of a power-supply control loop
• How to reduce the effects of noise when measuring power supply phase margin

Notes:

LeCroy Application Brief No. LAB 748. No publication date is specified for this document, but the time stamp in the oscilloscope measurements is 18-Dec-2000.

View the Source

Author & Publication:

no author specified, LeCroy, Vendor website, Dec 18 2000

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