O2micro International Limited

O2 Micro, Incorporated

02 Micro International Limited

02Micro Inc.

Marian Niculae

Constantin Bucur

Vlad Mihail Popescu-Stanesti

Alexandru Hartular

Vlad Popescu Stanesti

William Densham

Daryl Nees

Laszlo Lipcsei

Eftimie Caraghiorghiopol

Dan Simion

Guoying Yi

Doru Cioaca

Marian Udrea Spenea

Viorel Alexandru Marinescu

George Simion

Wiliam Densham

A driving circuit for an N-channel Metal Oxide Semiconductor (NMOS) transistor can include a charge pump unit and a driver coupled to the charge pump. The charge pump can receive a source voltage and output an output voltage higher than the source voltage, where the source voltage is applied to a source terminal of the NMOS transistor. The driver receives the output voltage of the charge pump unit and converts the output voltage to a driving voltage operable for conducting the NMOS transistor.

Power management systems with charge pumps

A power management system includes a first switch, a second switch, and a controller coupled to the first and second switches. The first switch has a first transfer terminal. The second switch has a second transfer terminal. The controller controls power conversion by turning on a third switch periodically. The first and second transfer terminals and a third transfer terminal of the third switch are coupled to a common node. The resistance between the first transfer terminal and the common node, the resistance between the second transfer terminal and the common node, and the resistance between the third transfer terminal and the common node are substantially equal to zero.

Power management systems

A method includes coupling a variable output DC power source to power control circuitry, and detecting a type of the variable output DC power source in response to the coupling operation. In one embodiment, the detecting operation may include sending an interrogation signal from the power control circuitry to the variable output DC power source, and evaluating a response to the interrogation signal to determine the type of said variable output DC power source. Power control circuitry may include source type recognition circuitry configured to detect a type of a variable output DC power source in response to a coupling of the variable output DC power source to the power control circuitry.

System, method and apparatus to automatically detect a type of a variable output DC power source

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.

Battery state monitoring circuitry with low power consumption during a stand-by-state of a battery pack

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.

Method and electronic circuit for efficient battery wake up charging

A battery pack may include at least one battery cell, a switch having an ON resistance dependent on a temperature of the switch, a thermistor having a resistance varying with changes in the temperature, and battery state monitoring circuitry. The battery state monitoring circuitry may be configured to monitor a voltage drop across the switch caused by a current flowing through the switch and the resistance of the thermistor to correlate the voltage drop to the current level. A cordless electrical device including the battery pack, and an associated method are also provided.

Battery pack current monitoring

A power supply topology according to one embodiment includes a first path coupled to a controllable DC power source, a second path coupled to a rechargeable battery, and a third path coupled to a system load, the three paths coupled to a common node. The topology may further include a unidirectional switch coupled to the first path and a selectively unidirectional switch coupled to the second path. The topology may further include a power management control circuit including a wake up circuit having a comparison circuit and an output decision circuit. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.

Power management topologies to control power between a DC power source and one or more batteries to a system load

Voltage translator circuitry may include a path including a first resistor, a current controlling device, and a second resistor coupled in series. The voltage translator circuitry may further include an operational amplifier having a positive supply terminal to accept a positive supply voltage and a negative supply terminal to accept a negative supply voltage, neither the positive or negative supply voltage at ground voltage. The first resistor may further be coupled to a positive terminal of the battery cell to be monitored. The operational amplifier may have an input coupled to a negative terminal of the battery cell to be monitored. The voltage translator circuitry may further include an output terminal coupled to a node of the path between the current controlling device and the second resistor. The output terminal may be configured to provide the ground referenced cell voltage for the battery cell.

Single floating battery cell voltage level translator circuitry

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 adjusts its output voltage in response to the magnitude of an error signal representing an amount by which instantaneous power consumption exceeds adapter maximum power. 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.

Supply topology with power limiting feedback loop

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.

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San Jose, CA, United States of America

Marian Niculae