Minimizing Switching Regulator Residue in Linear Regulator Outputs

Linear regulators are commonly employed to post-regulate switching regulator outputs. Benefits include improved stability, accuracy, transient response and lowered output impedance. Ideally, these performance gains would be accompanied by markedly reduced switching regulator generated ripple and spikes. In practice, all linear regulators encounter some difficulty with ripple and spikes, particularly as frequency rises. This video, excerpted from Application Note 101, explains the causes of linear regulators’ dynamic limitations and presents board level techniques for measuring and improving ripple and spike rejection.