O2micro International Limited

O2 Micro, Incorporated

02 Micro International Limited

Constantin Bucur

Marian Niculae

Vlad Mihail Popescu-Stanesti

William Densham

Flavius Lupu

Jiun Heng Goh

Stefan Maireanu

Vlad Popescu Stanesti

Alexandru Hartular

You-Yuh Jack Shyr

Daryl Nees

Chun Lu

Doru Cioaca

Emanuel Stoicescu

Xiaojun Zeng

Anquan Xiao

Jiwei Chen

Allan Flippin

Oleg Kobildjanov

Marian Udrea Spenea

Viorel Alexandru Marinescu

George Simion

Flavius Lupy

Kalyi Sheng

JiunHeng Goh

Wiliam Densham

In a power converter, a primary winding receives an input power. In addition, multiple secondary windings transform the input power into multiple charging currents to charge a set of cells via a set of paths. The multiple secondary windings further balance the set of cells based on the charging currents. A ratio between a first turn number of a first secondary winding of the secondary windings and a second turn number of a second secondary winding of the secondary windings is determined by a nominal voltage ratio between two corresponding cells of the set of cells.

Systems and methods for balancing battery cells

A battery management chip may include a battery management unit and a vertical bus circuit. The battery management unit can monitor a cell status of multiple cells in a battery module coupled to the battery management chip in response to an instruction from a host processor. The vertical bus circuit may transfer the instruction from the host processor to the battery management unit. The vertical bus circuit may include a first receiver, a command processor and a first transmitter. The first receiver can receive a first pair of differential input data signals. The command processor can process the first pair of differential input data signals. The first transmitter can output a first pair of differential output data signals.

Battery management systems with vertical bus circuits

A monitoring and control circuit comprises a sense block, a first and a second comparators, and a control module. The current sense block is coupled to a switch for generating a monitoring signal indicative of a current flowing through the switch. The first comparator coupled to the sense block is operable for comparing the monitoring signal to a first threshold and for providing a first signal according to a first comparison result between the monitoring signal and the first threshold. The second comparator coupled to the sense block is operable for comparing the monitoring signal to a second threshold and for providing a second signal according to a second comparison result between the monitoring signal and the second threshold. The control module coupled to the first comparator and the second comparator provides a control signal for controlling the switch according to the first signal and the second signal so as to adjust the current.

Monitoring and control circuit for adjusting current

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 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 first voltage and the second voltage.

Systems and methods for cell balancing

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.

Capacity detector for detecting capacity of an energy storage unit

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

An apparatus includes battery gauge circuitry implemented on an integrated circuit. The battery gauge circuitry includes a plurality of switches that individually open in response to a voltage reduction on a battery cell associated with a respective one of the switches. The battery gauge circuitry also includes a logic device that determines if at least one of the switches is open. The battery gauge circuitry also includes a register that stores data that indicates if at least one switch is open. The battery gauge circuitry also includes a controller that initiates halting power delivery to a load if at least one of the switches is open. The controller also identifies the open switch.

Monitoring battery cell voltage

A cell balancing circuit for balancing battery cells includes a transformer and a switching controller. The transformer has a primary winding and a secondary winding. The switching controller can select a first cell coupled to the primary winding and select a second cell coupled to the secondary winding. The first cell and the second cell are coupled in series. The first cell has a cell voltage that is greater than the second cell. The cell balancing circuit further includes a controller coupled to the primary winding. The controller controls energy from the first cell to the primary winding so as to transfer the energy from the first cell to the second cell to balance the battery cells.

Cell balancing systems employing transformers

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 protection circuit includes a detection block, a timer and a protection enable block. The detection block is used to compare a monitoring signal with a reference signal and generate an alert signal if a difference between the monitoring signal and the reference signal exceeds a threshold for a first predetermined duration. The timer coupled to the detection block is used to generate an enabling signal for a second predetermined duration in response to the alert signal. The protection enable block coupled to the timer is used to generate a triggering signal for a first time duration determined by the second predetermined duration in response to the enabling signal so as to perform a protection function.

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Constantin Bucur