Stability and Performance Improvement with Feedback in VRM Transconductance Error Amplifiers – A Case Study using the Sandler State Space Average VRM Model

The voltage regulator module (VRM) is the foundation of power integrity. Due to their wide bandwidth and low cost, most newer VRM controllers employ transconductance feedback amplifiers, with the VRM manufacturers recommending a shunt compensation for the error amplifier design. However, most VRM designers and power integrity engineers may not be aware that they have another choice to improve the sensitivity and performance of their VRM design. The better performance of a current mode VRM with series compensation for the error amplifier is clearly demonstrated with simulations using the Sandler state-space average VRM model.

Additional analysis and discussion will be provided to show how the VRM’s performance has improved stability, reduced gain sensitivity, and overall improved performance with a series compensation network. A VRM case study will be presented in this technical session to show these performance improvements using the Sandler State Space Average model in Keysight PathWave ADS.

*Steven M. Sandler & Heidi Barnes will be joining Benjamin Dannan to answer any questions during the live Q&A segment.

Power Integrity, Signal Integrity, Simulation, VRM Design, State-Space Average VRM model, Keysight PathWave ADS, Modeling, PDN Design, switched-mode power supply, NISM