Switching regulator having low power mode responsive to load power consumption

Abstract

A switching mode power converter monitors the level of power supplied to a load device. The operation of a switch is controlled and used to draw power from an input source and supply power to the load device. During normal operation, the operation of the switch is triggered on every clock pulse by a triggering pulse. The duty cycle of the triggering pulse is controlled by a pulse width modulation circuit which monitors the level of power being supplied to the load device. When the power being supplied to the load falls to a predetermined light load threshold level, representing that the load device is either in a standby mode or a period of light use, the switching mode power converter will reduce the amount of power being drawn from the input source by disabling the triggering pulse for an appropriate number of pulses of the clock signal. The number of pulses skipped will depend on an amount of power being supplied to the load device and an amount of voltage stored across the capacitor. The triggering pulse is re-enabled once the power being supplied to the load device rises above the light load threshold level or the voltage stored across the capacitor falls to a low threshold level. In this manner, during periods when the load device is not operating in the continuous conduction mode, the switching mode power converter will attempt to minimize the amount of power being drawn from the input source.

Dependencies are inferred from the claim text.