| O2MICRO INTERNATIONAL LIMITED Patent applications |
| Patent application number | Title | Published |
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| 20120043948 | SYSTEM, METHOD AND APPARATUS TO AUTOMATICALLY DETECT A TYPE OF A VARIABLE OUTPUT DC POWER SOURCE - 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. | 02-23-2012 |
| 20110298425 | BATTERY CELL MONITORING AND BALANCING CIRCUIT - A monitoring circuit for accurately monitoring a voltage level from each of a plurality of battery cells of a battery pack includes an analog to digital converter (ADC) and a processor. The ADC is configured to accept an analog voltage signal from each of the plurality of battery cells and convert each analog voltage signal to a digital signal representative of an accurate voltage level of each battery cell. The processor receives such signals and provides a safety alert signal based on at least one of the signals. The ADC resolution may be adjustable. A balancing circuit provides a balancing signal if at least two of the digital signals indicate a voltage difference between two cells is greater than a battery cell balance threshold. An electronic device including such monitoring and balancing circuits is also provided. Various methods are also provided. | 12-08-2011 |
| 20110289239 | DEVICE ADDRESS ASSIGNMENT IN A BUS CASCADE SYSTEM - According to one aspect there is disclosed an apparatus. The apparatus may include a first device. The first device may include a first serial input port configured to receive serial data from at least one of a host MCU and a second device; a first serial output port configured to output the serial data to a third device when the third device is coupled to the first device; a first shift register configured to receive the serial data from the first serial input port; a first multiplexer configured to selectively couple the first serial output port to the first shift register or the first serial input port; and a bus controller configured to receive the serial data from the first serial input port, the bus controller further configured to control the first multiplexer to couple the first serial output port to the first serial input port or the first shift register, based at least in part on the serial data, wherein the serial data includes a command section of a command and at least a portion of a payload section of the command, wherein the command section includes a command code, a target address and an error check and the payload section includes at least one new address and at least one corresponding error check. | 11-24-2011 |
| 20110121653 | PARALLEL POWERING OF PORTABLE ELECTRICAL DEVICES - A system may include an electronic device configured to consume a supply current; an AC to DC adapter configured to be coupled to the electronic device, wherein the AC to DC adapter has a maximum rated output current; a battery configured to be coupled to the electronic device; DC to DC converter configured to be coupled to the battery and the electronic device; and a controller configured to couple the AC to DC adapter to the electronic device, the controller further configured to couple the DC to DC converter to the battery and the electronic device when the supply current exceeds the maximum rated output current of the AC to DC adapter. | 05-26-2011 |
| 20110074839 | CONTROLLER CIRCUITRY FOR LIGHT EMITTING DIODES - A method according to one embodiment may include supplying power to an LED array having at least a first string of LEDs and a second string of LEDs coupled in parallel, each of the strings includes at least two LEDs. The method of this embodiment may also include comparing a first feedback signal from the first string of LEDs and a second feedback signal from the second string of LEDs. The first feedback signal is proportional to current in said first string of LEDs and said second feedback signal is proportional to current in said second string of LEDs. The method of this embodiment may also include controlling a voltage drop of at least the first string of LEDs to adjust the current of the first string of LEDs relative to the second string of LEDs, based on, at least in part, the comparing of the first and second feedback signals. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment. | 03-31-2011 |
| 20110057586 | MONITORING BATTERY CELL VOLTAGE - 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. | 03-10-2011 |
| 20110043168 | MONITORING BATTERY CELL VOLTAGE - 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. | 02-24-2011 |
| 20100327813 | POWER MANAGEMENT TOPOLOGIES - 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. | 12-30-2010 |
| 20100308779 | SYSTEM, METHOD AND APPARATUS TO AUTOMATICALLY DETECT A TYPE OF A VARIABLE OUTPUT DC POWER SOURCE - 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. | 12-09-2010 |
| 20100171502 | BATTERY STATE MONITORING CIRCUITRY WITH LOW POWER CONSUMPTION DURING A STAND-BY-STATE OF A BATTERY PACK - 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. | 07-08-2010 |
| 20100171467 | BATTERY STATE MONITORING CIRCUITRY WITH LOW POWER CONSUMPTION DURING A STAND-BY-STATE OF A BATTERY PACK - 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. | 07-08-2010 |
| 20100026213 | INTEGRATED CIRCUIT CAPABLE OF SYNCHRONIZATION SIGNAL DETECTION - A method according to one embodiment may include providing power to at least one light source. The method of this embodiment may also include detecting the frequency of at least one vertical synchronization signal, among a plurality of different synchronization signals, and controlling the power to at least one light source based on, at least in part, the detected frequency of at least one vertical synchronization signal. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment. | 02-04-2010 |
| 20100007350 | OVER VOLTAGE TRANSIENT CONTROLLER - An over voltage transient controller to protect a rechargeable battery from an over voltage transient condition. The over voltage transient controller may comprise a comparator to compare a first signal with a second signal representative of a reference voltage level and to provide an output signal representative of an over voltage transient condition to a switch if the first signal is greater than or equal to the second signal. The switch is responsive to the output signal to protect the rechargeable battery from the over voltage transient condition. The over voltage transient controller may further comprise a DAC, wherein the second signal is based, at least in part, on an output of the DAC. An apparatus comprising a charge switch and such an over voltage transient controller is also provided. | 01-14-2010 |
| 20090206795 | SELECTOR CIRCUIT FOR POWER MANAGEMENT IN MULTIPLE BATTERY SYSTEMS - 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. | 08-20-2009 |
| 20090167091 | SELECTOR CIRCUIT FOR POWER MANAGEMENT IN MULTIPLE BATTERY SYSTEMS - 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. | 07-02-2009 |
| 20090045775 | Charging Circuit for Parallel Charging in Multiple Battery Systems - 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. | 02-19-2009 |
| 20090033373 | Circuit and Method for Trimming Integrated Circuits - A programmable after-package, on-chip reference voltage trim circuit for an integrated circuit having a plurality of programmable trim cells generating a programmed sequence. A converter is provided to convert the bit sequence into a trim current. The trim current is added to an initial value of a reference voltage to be trimmed, as generated by the integrated circuit. Once the correct value of the trim current is determined, isolation circuitry is programmed to isolate the trim circuitry from the remainder of the IC, thereby freeing the logic and package pins associated with the IC for use by users of the IC. The preferred trim circuitry includes fuses which are blown in accordance with a bit value supplied to the trim cell to permanently fix a trim current value, once a best fit value is determined. | 02-05-2009 |
| 20080232139 | Power Converter - The present disclosure is directed towards a method for power conversion. The method may include controlling a first rectifier switch coupled to one end of a secondary winding of a transformer via a first control signal. The method may further include controlling a first low side switch via said first control signal, said first low side switch and a first high side switch coupled in series along a first path of a full bridge circuit, a first node located between said first high side switch and said first low side switch. The method may also include controlling a second rectifier switch coupled to an opposite end of said secondary winding via a second control signal. The method may additionally include controlling a second low side switch via said second control signal, said second low side switch and a second high side switch coupled in series along a second path of said full bridge circuit, a second node located between said second high side switch and said second low side switch, wherein said primary winding is coupled between said first node and said second node. Of course additional embodiments are also within the scope of the present disclosure. | 09-25-2008 |
| 20080231117 | POWER MANAGEMENT TOPOLOGIES - 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. | 09-25-2008 |
| 20080211426 | Lamp Current Balancing Topologies - A method according to on embodiment may include generating AC voltage and current and a striking voltage. The method of this embodiment may also include generating striking voltage and steady-state voltage for at least two lamp loads. The method of this embodiment may also include coupling at least two lamp loads in parallel. The method of this embodiment may also include coupling current balancing circuitry to the at least two lamp loads and providing, by the current balancing circuitry simultaneous striking voltage to the at least two lamps loads. The method of this embodiment may also include balancing, by the current balancing circuitry, AC current through the at least two lamp loads. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment. | 09-04-2008 |
| 20080211305 | Circuit structure for driving a plurality of cold cathode fluorescent lamps - A DC/AC converter circuit structure for driving a plurality of cold cathode fluorescent lamps is described. A common-mode choke is used between the cold cathode fluorescent lamps. The common-mode choke balances the currents respectively flowing through the cold cathode fluorescent lamps. | 09-04-2008 |
