Powering Down Switching Regulator using a Ramped Reference Voltage

摘要

Circuits and related methods for energy efficient battery supplied switching DC-to-DC regulators are disclosed. When entering a power-down state the energy in an output capacitor is harvested and charged back to the battery. This is achieved by ramping-down a reference voltage after a power-down sequence is initiated. The output voltage of the regulator is ramped-down accordingly. At the end of the power down sequence the output voltage of the regulator is down to 0V. The disclosure is especially important for regulators, which frequently are started up and switched down.