Abstract: One embodiment includes a power system. The system includes a power switch device that is activated to provide an output voltage to a load in response to an input voltage. The power switch device includes a control terminal and a bulk connection. The system also includes a reverse voltage control circuit configured to passively couple the input voltage to one of the control terminal and the bulk connection in response to a reverse voltage condition in which an amplitude of the input voltage becomes negative. The system further includes an output shutoff circuit configured to passively couple the output voltage to a neutral-voltage rail during the reverse voltage condition.

Abstract: Methods and systems are presented for charging and/or discharging multiple parallel-connected battery packs in portable electronic devices, in which a charging or discharging current of a second battery pack is regulated based at least in part on a charging or discharging current of a first battery pack.

Abstract: One embodiment includes a power system. The system includes a power switch device that is activated to provide an output voltage to a load in response to an input voltage. The power switch device includes a control terminal and a bulk connection. The system also includes a reverse voltage control circuit configured to passively couple the input voltage to one of the control terminal and the bulk connection in response to a reverse voltage condition in which an amplitude of the input voltage becomes negative. The system further includes an output shutoff circuit configured to passively couple the output voltage to a neutral-voltage rail during the reverse voltage condition.

Abstract: A battery cell tab monitoring apparatus includes a conductive element electrically connected between two battery cells. The conductive element is connected to a sensing circuit including a pull-down current source connected to pull current from the conductive element and/or a pull-up current source connected to drive current into the conductive element. A voltage measuring circuit is connected to sense voltages during operation of the pull-down current source and the pull-up current source to be used to determine the status of the conductive element. For instance, voltages beyond certain fixed or variable thresholds indicate that the conductive element is flexing or cracking, which can be a precursor to its breaking. Voltages beyond other fixed or variable thresholds indicate that the conductive element is fully disconnected. The current sources used to push and pull the sensing currents may be used to bring the battery cells into balance when an imbalance is detected.

Abstract: A control circuit of a battery power-path management circuit establishes a first power path between a battery input node and an output node when the input node voltage is larger than a charger input node voltage and a second power path between the charger input node and the output node when the voltage on the charger input node is larger than the battery input node voltage. It controls the second power path to provide power to the output node, enabling battery charging and protection over a battery voltage range from about zero volts. It has low power consumption and can support wide-swing power supply voltage from as low as one volt to as high as maximum allowed Vds of drain-extended devices. It can use smaller device sizes because the PMOS switch gate voltage is 0V when the power supply is not too high.

Abstract: A control circuit of a battery power-path management circuit establishes a first power path between a battery input node and an output node when the input node voltage is larger than a charger input node voltage and a second power path between the charger input node and the output node when the voltage on the charger input node is larger than the battery input node voltage. It controls the second power path to provide power to the output node, enabling battery charging and protection over a battery voltage range from about zero volts. It has low power consumption and can support wide-swing power supply voltage from as low as one volt to as high as maximum allowed Vds of drain-extended devices. It can use smaller device sizes because the PMOS switch gate voltage is 0V when the power supply is not too high.

Abstract: A battery cell tab monitoring apparatus includes a conductive element electrically connected between two battery cells. The conductive element is connected to a sensing circuit including a pull-down current source connected to pull current from the conductive element and/or a pull-up current source connected to drive current into the conductive element. A voltage measuring circuit is connected to sense voltages during operation of the pull-down current source and the pull-up current source to be used to determine the status of the conductive element. For instance, voltages beyond certain fixed or variable thresholds indicate that the conductive element is flexing or cracking, which can be a precursor to its breaking. Voltages beyond other fixed or variable thresholds indicate that the conductive element is fully disconnected. The current sources used to push and pull the sensing currents may be used to bring the battery cells into balance when an imbalance is detected.

Abstract: A battery management system for charging a battery by a charger includes a transistor and either a charge pump or a push-pull output driver. The transistor increases and decreases an electrical connection between the battery and a voltage from the charger and transmits a charge current from the charger to the battery by turning on and off in response to a pulse width modulated drive signal generated by the charge pump or the push-pull output driver. The charge pump or the push-pull output driver increases the drive signal when the voltage from the charger is above a pre-charge threshold voltage and decreases the drive signal when the voltage from the charger is below the pre-charge threshold voltage.

Abstract: Systems and methods are provided for adjusting the frequency of an oscillator to compensate for oscillator frequency variations resulting from changes in oscillator parameters. Measurement systems monitor one or more oscillator parameters. The capacitance of the oscillator is selectively adjusted based on the measurement of the one or more oscillator parameters. The change in capacitance compensates for changes in environmental and operating conditions that affect the oscillator parameters, such as temperature and applied voltage, and produces a relatively stable output frequency over a specified operating range.