Abstract: A battery pack including at least one battery cell, a switch, and battery state monitoring circuitry. The battery state monitoring circuitry may be configured to control an ON resistance of the switch to a first ON resistance when the switch is ON and the battery pack is in a stand-by-state and to control the ON resistance to a second ON resistance when the switch is ON and said battery pack is not in said stand-by-state, the first ON resistance greater than the second ON resistance. A cordless electrical device and method consistent with embodiments are also provided.

Abstract: A battery pack including at least one battery cell, a switch, and battery state monitoring circuitry. The battery state monitoring circuitry may be configured to control an ON resistance of the switch to a first ON resistance when the switch is ON and the battery pack is in a stand-by-state and to control the ON resistance to a second ON resistance when the switch is ON and said battery pack is not in said stand-by-state, the first ON resistance greater than the second ON resistance. A cordless electrical device and method consistent with embodiments are also provided.

Abstract: A battery pack including at least one battery cell, a switch, and battery state monitoring circuitry. The battery state monitoring circuitry may be configured to control an ON resistance of the switch to a first ON resistance when the switch is ON and the battery pack is in a stand-by-state and to control the ON resistance to a second ON resistance when the switch is ON and said battery pack is not in said stand-by-state, the first ON resistance greater than the second ON resistance. A cordless electrical device and method consistent with embodiments are also provided.

Abstract: A supply topology comprising an AC to DC or DC to DC adapter and an electronic device with an active system, a battery, and an adapter controller implements closed-loop control of adapter output voltage to limit power consumption by the electronic device to a value related to maximum adapter power. The adapter couples a signal representing maximum adapter power to a control line connected to the electronic device and the electronic device couples an error signal representing the difference between instantaneous power consumption and adapter maximum power onto the same control line. The adapter adjusts its output voltage in response to the magnitude of the error signal. An adapter controller in the electronic device sets a limit for allocating current to battery charging from the signal representing maximum adapter power, with battery charging current approaching zero as instantaneous power consumption approaches maximum adapter power.

Abstract: A supply topology comprising an AC to DC or DC to DC adapter and an electronic device with an active system, a battery, and an adapter controller implements closed-loop control of adapter output voltage to limit power consumption by the electronic device to a value related to maximum adapter power. The adapter couples a signal representing maximum adapter power to a control line connected to the electronic device and the electronic device couples an error signal representing the difference between instantaneous power consumption and adapter maximum power onto the same control line. The adapter adjusts its output voltage in response to the magnitude of the error signal. An adapter controller in the electronic device sets a limit for allocating current to battery charging from the signal representing maximum adapter power, with battery charging current approaching zero as instantaneous power consumption approaches maximum adapter power.

Abstract: A method for efficiently charging a battery. The method includes producing a first signal having a voltage level dependent on the voltage of the battery comparing the voltage level of the first signal with a settable voltage representative of a maximum battery charging current, and producing a second signal representative of a charging current to be provided to the battery, the second signal having a voltage level selected to be the lower voltage level between the first signal and the settable voltage.

Abstract: A current mode charger controller for controlling a DC to DC converter. The current mode charger may include a first error amplifier having an output coupled to a common node. The first error amplifier may be configured to compare a first signal representative of a charging current provided to a rechargeable battery with a maximum charging current and provide a current control signal in response to the comparison. The current mode charger controller may further include an internal compensation network coupled to the common node, and a comparator configured to compare an inductor current signal representative of an inductor current through an inductor of the DC to DC converter with a compensation signal. The need for any external compensation for the current mode charger controller may be eliminated.

Abstract: A capacity detector for detecting capacity of an energy storage unit includes a first and a second buffers and a voltage divider. The first buffer is used for generating a first threshold reference according to a first adjustable reference which is predetermined based upon chemistry of the energy storage unit. The second buffer is used for generating a second threshold reference according to a second adjustable reference which is predetermined based upon chemistry of the energy storage unit. The voltage divider coupled to the first buffer and the second buffer is used for dividing a voltage across the first threshold reference and the second threshold reference and for generating capacity references indicating capacity percentages of the energy storage unit according to a voltage versus capacity characteristic of the energy storage unit.

Abstract: Power control circuitry and method for controlling a variable output DC power source. The power control circuitry may include a first comparator to compare a signal representative of an output current level of the variable output DC power source with a threshold level and provide a first output signal in response to the comparison. The power control circuitry may further include threshold input circuitry to provide the threshold level to the first comparator, the threshold level being a fixed threshold level if an output voltage of the variable output DC power source is less than or equal to a first fixed voltage level, the threshold level being a variable threshold level if the output voltage is greater than the first fixed voltage level.

Abstract: A selector circuit configured to select among a DC power source and a plurality of batteries for an electronic device. The selector circuit is responsive to an output signal from an associated power management unit. The selector circuit is further configured to permit parallel operation of two or more of the batteries. The selector circuit may further act to independently verify power conditions and override instructions from the PMU in certain instances to enhance power supply safety and battery life such as by preventing inter battery current flow from a higher potential battery to a lower potential battery coupled in parallel.

Abstract: A method for efficiently charging a battery. The method includes producing a first signal having a voltage level dependent on the voltage of the battery, comparing the voltage level of the first signal with a settable voltage representative of a maximum battery charging current, and producing a second signal representative of a charging current to be provided to the battery, the second signal having a voltage level selected to be the lower voltage level between the first signal and the settable voltage.

Abstract: A selector circuit configured to select among a DC power source and a plurality of batteries for an electronic device. The selector circuit includes a first comparator configured to compare a first input signal representative of a voltage level of the DC power source with a first threshold level and provide a first output signal representative of a difference between the first input signal and the first threshold level, and a selector output circuit. The selector output circuit is configured to provide selector output signals that control selection among the DC power source and the plurality of batteries. The selector output circuit providing said selector output signals to select the DC source and deselect the plurality of batteries if the first output signal is representative of the voltage level of said DC power source being greater than the first threshold level.

Abstract: An apparatus for detecting temperature includes an adjustable current source operable for supplying a current, a thermistor coupled to said adjustable current source, and an auto-range hysteresis logic coupled to said thermistor and said adjustable current source operable for outputting a signal to control said adjustable current source by sensing a voltage across said thermistor. A method for detecting temperature is also disclosed.

Abstract: A cell balancing circuit comprises a first cell having a first voltage, a second cell in series with the first cell and having a second voltage that is greater than the first voltage, and a bypass path in parallel with the second cell for enabling a bypass current for the second cell if a difference between the first voltage and the second voltage is greater than a predetermined threshold. The bypass current is enabled for a balancing time period that is proportional to the difference between the fist voltage and the second voltage.

Abstract: A cell balancing circuit comprises a first cell having a first voltage, a second cell in series with the first cell and having a second voltage that is greater than the first voltage, and a bypass path in parallel with the second cell for enabling a bypass current for the second cell if a difference between the first voltage and the second voltage is greater than a predetermined threshold. The bypass current is enabled for a balancing time period that is proportional to the difference between the fist voltage and the second voltage.

Abstract: A controller for a DC to DC converter. The controller may comprise linear mode circuitry and switch mode control circuitry. The linear mode control circuitry may be capable of providing a first control signal to a controlled device of the DC to DC converter. The controlled device may operate as a variable resistor in response to the first control signal to control an output voltage of the DC to DC converter. The switch mode control circuitry may be capable of providing a second control signal to the controlled device of the DC to DC converter. The controlled device may turn ON and OFF in response to the second control signal to control the output voltage of the DC to DC converter. One of the linear mode control circuitry and the switch mode control circuitry may be enabled. The controller may also include protection circuitry.

Abstract: A selector circuit configured to select among a DC power source and a plurality of batteries for an electronic device. The selector circuit includes a first comparator configured to compare a first input signal representative of a voltage level of the DC power source with a first threshold level and provide a first output signal representative of a difference between the first input signal and the first threshold level, and a selector output circuit. The selector output circuit is configured to provide selector output signals that control selection among the DC power source and the plurality of batteries. The selector output circuit providing said selector output signals to select the DC source and deselect the plurality of batteries if the first output signal is representative of the voltage level of said DC power source being greater than the first threshold level.

Abstract: A charging circuit for controlling a system charging parameter provided to a host of rechargeable batteries, wherein the host of batteries includes at least a first battery and second battery that may be coupled in parallel. The charging circuit provides for fast charging of rechargeable batteries in parallel. Independent current and voltage sensing for each battery enables parallel charging of batteries at different charging currents. The charging circuit may be configured to accept either analog or digital signals from an associated power management unit.

Abstract: A selector circuit configured to select among a DC power source and a plurality of batteries for an electronic device. The selector circuit is responsive to an output signal from an associated power management unit. The selector circuit is further configured to permit parallel operation of two or more of the batteries. The selector circuit may further act to independently verify power conditions and override instructions from the PMU in certain instances to enhance power supply safety and battery life such as by preventing inter battery current flow from a higher potential battery to a lower potential battery coupled in parallel.

Abstract: The present disclosure provides a method for filtering in a cordless electrical device. The method may include coupling a filter network, a microcontroller and a plurality of battery cells having a cell voltage and a current. The method may further include operatively connecting at least one switched capacitor low-pass filter to the plurality of battery cells, the at least one switched capacitor low-pass filter configured to receive a signal from the filter network. The method may also include filtering the signal from the filter network, delivering a filtered signal input to an ADC and generating an output from the ADC.