Active transient response circuits, system and method for digital multiphase pulse width modulated regulators

摘要

Disclosed is a multi-phase pulse width modulated voltage regulator and method in which transient voltage excursions or deviations that exceed the load line voltage by more than a pre-determined amount are detected by an ATR circuit and a correction signal is applied. The correction signal is in the form of asynchronous pulses and the number of such pulses is a function of the magnitude of the voltage excursion as determined by the number of thresholds that are exceeded. Also disclosed is an adaptive voltage positioning (AVP) circuit and method for early detection of a transient event by sensing voltage changes at the load and adjusting the target voltage with pre-determined current values prior to the time that ATR event changes in the current at the load are detected. The AVP load line is pre-positioned for more precise current control. Also disclosed is an adaptive filter with adjustable frequency characteristics in response to an ATR event. Also disclosed is a pulse limiting circuit. Also disclosed is a tri-state implementation. Response to transient events is further improved with an external ATR circuit coupled to the load.