Many signal and power integrity issues are the result of poor VRM selection. This critical selection is often made arbitrarily due to insufficient, incomplete or incorrect data. Costly design time and multiple board spins can be minimized by following a few simple guidelines and performing a few simple simulations and measurements early in the process.
This video explains why one should avoid Voltage mode VRMs and shunt compensation for the VRM Error Amplifier. The better performance of a current mode VRM with series compensation for the Error Amplifier is clearly demonstrated with simulations and measurements.