Patent ID: 9472967
Filing Date: 2016-10-18
CPC Classification: B60L,H02J,Y02T

Claim Text:
1. A power management system for a portable device, comprising: a power management controller that compares an input voltage provided by a battery of the portable device to a shutdown threshold and initiates a shutdown of the portable device when the input voltage falls below the shutdown threshold; a voltage monitoring switch having an output that connects first or second inputs to the power management controller in response to a control input, the first input connected to a positive battery terminal of the battery of the portable device, the second input connected to a voltage source that is higher than the shutdown threshold, wherein the voltage monitoring switch alternately connects either the first input or the second input to the output responsive to a control signal provided to the control input; a current sense circuit that provides the control signal to the voltage monitoring switch based on an input current through the positive battery terminal of the portable device, wherein when the input current exceeds a high current threshold, the circuit provides the control signal at a level that causes the voltage monitoring switch to connect the second input to the output, and wherein the control signal is provided to cause the voltage monitoring switch to connect the first input to the output otherwise; a boost converter that provides a boost voltage from the battery voltage provided at the positive battery terminal; a high voltage circuit powered by the boost converter; a battery voltage circuit; and a boost switch that is responsive to the control signal provided by the current sense circuit and connects the battery voltage circuit to a battery voltage provided by the positive battery terminal when the input current is below the high current threshold and connects the battery voltage circuit to the boost voltage provided by the boost converter when the input current exceeds the high current threshold.