O2micro International Limited

02 Micro International Limited

02micro Inc.

O2 Micro, Incorporated

Vlad Mihail Popescu-Stanesti

Constantin Bucur

Marian Niculae

You-Yuh Jack Shyr

Constantin Spiridon

Daryl Nees

William Densham

Alexandru Hartular

Footshen Wong

Jiwei Chen

Oleg Kobildjanov

Laszlo Lipcsei

Chun Lu

Ming Han

Foot Shen Wong

Mingkwang Han

William L Densham

Winson Wong

Mingkwong Han

Xiachua Hou

ChunHsi Lin

Stephen Gustafson

Jacky Lin

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

The present invention is an apparatus for driving white LEDs. The apparatus includes a switchable current sink, a DC-DC converter and a reference circuit. The DC-DC converter provides a driving voltage to a plurality of LEDs. The switchable current sink regulates currents through the plurality of LEDs, and the switchable current sink further provides a first reference voltage and outputs a plurality of voltage drops. The reference circuit receives the first reference voltage and the plurality of voltage drops to provide a second reference voltage to the DC-DC converter. The DC-DC converter adjusts the driving voltage provided to the plurality of LEDs according to the second reference voltage. In this way, the driving voltage is regulated to a minimum possible value and consequently the voltage drops across the switchable current sink is minimized. Hence, the LED driving system maintains higher efficiency.

Apparatus and method for regulating white LEDs

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.

Selector circuit for power management in multiple battery systems

A DC to DC converter for converting an input DC voltage to an output DC voltage. The DC to DC converter may include at least one switch, an inductor coupled to the at least one switch, and a controller capable of providing a control signal. The at least one switch may be responsive to the control signal in a first state to enter an ON state for an ON time interval, the ON time interval based on the input DC voltage and a constant. An electronic device including such a DC to DC converter and related methods are also provided.

Boost converter with enhanced control capabilities of emulating an inductor current

A method according to one embodiment may include selecting at least one power supply, among a plurality of different power supplies, and coupling at least one available power supply to a load. The method may also include selecting at least one charging mode, among a plurality of different charging modes, to charge a rechargeable battery. Of course, many alternatives, variations, and modifications are possible without departing from this embodiment.

Power management system

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.

Controller for a DC to DC converter having linear mode and switch mode capabilities

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.

Charging circuit for parallel charging in multiple battery systems

A circuit according to the present invention is used for driving a photoflash diode and comprises a current sink, a feedback circuit, and a DC-DC converter. The current sink is coupled to the photoflash diode for controlling the current through the photoflash diode. The feedback circuit receives a feedback signal indicative of the electrical condition of said first current regulator. The DC-DC converter is coupled to an external power source and the feedback circuit for powering the photoflash diode so as to control the electrical condition of the current sink to a predetermined value.

Highly efficient driving of photoflash diodes using low and fixed voltage drop-out current sink

A wake up circuit according to one embodiment includes a comparison circuit and an output decision circuit. The comparison circuit may be adapted to receive a first signal representative of a charging current level provided to a battery via a path and a second signal representative of a predetermined wake up current level and to provide a comparison output signal in response to the first and second signal. The output decision circuit may be adapted to receive at least the comparison output signal and a selector signal from a selector circuit, the output decision circuit providing one of the comparison output signal and the selector signal to a switch to control a state of the switch, the switch coupled to the path.

Power management topologies

A DC to DC controller for controlling an inrush current from a DC to DC converter to a battery system having an internal isolating switch. The DC to DC controller is configured to control the DC to DC converter based on a state of the internal isolating switch. If the switch is open, the DC to DC controller adjusts the output voltage of the DC to DC converter to a predetermined voltage level. Based on the value of such voltage level, in rush current from the DC to DC converter to the battery system can be reduced or eliminated when the isolating switch changes from an open state to a closed state. An electronic device including such a DC to DC controller is provided. Related methods for controlling inrush current are also provided.

DC to DC controller with inrush current protection

In one aspect the present invention provides an AC/DC or DC/DC adapter, comprising circuitry to generate a signal proportional to the maximum adapter current. In another aspect, the present invention provides a portable electronic device, comprising circuitry to receive a signal proportional to the maximum current supplied to the portable electronic device and a charger controller. Still another aspect of the present invention provides an adapter topology system, comprising an AC/DC or DC/DC adapter comprising circuitry to generate a signal proportional to the maximum adapter current; and a portable electronic device adapted to receive power from said adapter and to receive said signal proportional to the maximum adapter current.

Intelligent adapter

A power management topology for portable electronic devices that includes a feed-enabled AC/DC adapter that receives feedback data from a charge controller associated with the portable device. The feedback data can include battery charging current, battery voltage, or power requirements of the portable device. Using the feedback data, the external AC/DC adapter can adjust the DC output to meet the charging requirement of the battery and/or the power requirements of the portable device.

Power management for battery powered appliances

A battery charging circuit is disclosed that includes protection circuitry and/or adapter current limit offset circuitry. The protection circuitry is operable to reduce or eliminate an overvoltage and overcurrent condition generated by a charge controller when a charging path is an open circuit, for example, when a battery is disconnected from the charging path. The adapter current limit offset circuitry is operable to generate an offset signal to an adapter current signal utilized by a charger controller.

Growing community of inventors

San Jose, CA, United States of America

Vlad Mihail Popescu-Stanesti