Overcurrent protection in a battery charger
AssigneeIntersil Americas Inc.
InventorsJohn Stuart Kleine, Lei Zhao, Jia Wei
Life of this patent
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Abstract
Systems and methods are provided for overcurrent protection in a battery charger. In certain embodiments, a method includes turning on an adapter switch to receive electrical power from an adapter connected to the battery charger; controlling a switching regulator to direct electrical current between the switching regulator and a battery port. Further, the method includes sensing a voltage drop that is related to the electrical current passing between the switching regulator and the battery port; comparing the sensed voltage drop against at least one reference voltage; and, when the sensed voltage exceeds the reference voltage, changing operation of the adapter switch to protect the battery charger from an overcurrent state.
Claims21
A method for overcurrent protection in a battery charger, the method comprising:
- turning on an adapter switch to receive electrical power from an adapter connected to the battery charger;
- controlling a switching regulator to direct electrical current between the switching regulator and a battery port;
- sensing a voltage drop that is related to the electrical current passing between the switching regulator and the battery port;
- comparing the sensed voltage drop against at least one reference voltage;
- and
- when the sensed voltage exceeds the reference voltage, changing operation of the adapter switch to protect the battery charger from an overcurrent state.
A circuit for overcurrent protection, the circuit comprising:
- at least one switching regulator input node coupled to receive a switching regulator voltage, wherein the switching regulator is capable of directing a portion of current provided through an adapter switch to at least one of a system load port and a battery port;
- at least one sense resistor input node coupled to receive a sense resistor voltage;
- at least one amplifier configured to provide an output signal proportional to the difference between the switching regulator voltage and the sense resistor voltage;
- and
- at least one threshold comparator configured to provide a comparison signal based on the comparison of the output signal against an overcurrent reference voltage, wherein the comparison signal is used to control the adapter switch.
A system for a battery powered system load, the system comprising:
- an adapter, the adapter connectable to a power source, wherein the adapter alters current provided by the power source;
- a battery configured to store a portion of energy provided by the power source and to provide stored energy;
- a system load configured to use a portion of the current provided by the power source and a portion of stored energy provided from the battery;
- and
- a battery charger coupled between the adapter, the battery, and the system load, wherein the adapter adapts the current provided by the power source for use by the battery charger, the battery charger comprising:
- an adapter switch configured to control access to the power provided by the adapter to the battery charger;
- a battery switch configured to control discharging of the stored energy provided by the battery;
- a switching regulator configured to control switching between the power provided by the adapter and the stored energy provided by the battery;
- a sense resistor coupled between the switching regulator and the battery;
- and
- a monitor and control circuit configured to monitor the voltage drop across the sense resistor to determine when the battery charger is in an overcurrent state, the monitor and control circuit comprising:
- at least one amplifier configured to provide an output signal proportional to the voltage drop across the sense resistor;
- at least one threshold comparator configured to compare the output signal against an overcurrent reference voltage, wherein the comparison signal is used to control the adapter switch and the switching regulator.
Dependencies are inferred from the claim text.