Abstract: Embodiments of the present invention include charge pump circuits and methods. In one embodiment, a first charge pump receives a voltage and generates a first charge pump output voltage and current for supplying the power requirements of a circuit. A second charge pump is coupled in series with the first charge pump. The second charge pump generates a second charge pump output voltage and current for supplying different power requirements of the circuit. In one embodiment, the first charge pump provides a high current low voltage output to a first circuit and the second charge pump provides a low current high voltage output to a second circuit. Capacitors of the first charge pump may be external to an integrated circuit and capacitors of the second charge pump may be internal to the integrated circuit.

Abstract: Embodiments of the present invention include circuits and methods for calibrating lens displacement in a voltage controlled actuator. In one embodiment, a calibration circuit comprises a programmable voltage source that provides a voltage to a control terminal of an actuator to set a lens displacement, a switch that selectively decouples said programmable voltage source from said control terminal, a current source that provides a reference current to said control terminal when the control terminal is decoupled from said programmable voltage source, a comparator that senses a voltage difference between said programmable voltage source and said control terminal, and a timer coupled to an output of the comparator. The timer measures a time period required to increase the control terminal voltage. The capacitance of the actuator may be determined and used to calibrate the position of a lens.

Abstract: In one embodiment the present invention includes a system and method of charging a battery using a switching regulator. In one embodiment, a switching regulator receives an input voltage and input current. The output of the switching regulator is coupled to a battery to be charged. The switching regulator provides a current into the battery that is larger than the current into the switching regulator. As the voltage on the battery increases, the current provided by the switching regulator is reduced. The present invention may be implemented using either analog or digital techniques for reducing the current into the battery as the battery voltage increases.

Abstract: Embodiments of the present invention include systems and methods of controlling power in battery operated systems. In one embodiment, the present invention includes a switching regulator for boosting voltage on a depleted battery to power up a system. The system may communicate with an external system to increase the current received from the external system. Embodiments of the present invention include circuits for controlling power received from external power sources such as a USB power source. In another embodiment, input-output control techniques are disclosed for controlling the delivery of power to a system or charging a system battery, or both, from an external power source.

Abstract: Embodiments of the present invention include techniques for charging a battery using a regulator. In one embodiment, the present invention includes an electronic circuit comprising a regulator having an input coupled to a power source for receiving a voltage and a current and an output for providing an output current, an input voltage detection circuit coupled to the power source, and an adjustable current limit circuit for controlling the input or output current of the regulator, wherein input voltage detection circuit monitors the voltage from the power source and the adjustable current limit circuit changes the input or output current of the regulator to optimize the power drawn from power source.

Abstract: In one embodiment the present invention includes an over-current protection method. The method comprises generating a switching signal, starting and stopping a timer, sensing a current through a switch, comparing a response time to a reference time, and generating an over-current alarm signal. The switching signal activates one or more switches in a switching regulator. The timer is started in response to the switch being activated and is stopped in response to the sensed current exceeding a threshold. The response time indicates the time period between the starting and the stopping of the timer. The over-current alarm signal is generated if the response time is less than the reference time.

Abstract: In one embodiment the present invention includes a system and method of charging a battery using a switching regulator. In one embodiment, a switching regulator receives an input voltage and input current. The output of the switching regulator is coupled to a battery to be charged. The switching regulator provides a current into the battery that is larger than the current into the switching regulator. As the voltage on the battery increases, the current provided by the switching regulator is reduced. The present invention may be implemented using either analog or digital techniques for reducing the current into the battery as the battery voltage increases.

Abstract: Embodiments of the present invention include circuits and methods for calibrating lens displacement in a voltage controlled actuator. In one embodiment, a calibration circuit comprises a programmable voltage source that provides a voltage to a control terminal of an actuator to set a lens displacement, a switch that selectively decouples said programmable voltage source from said control terminal, a current source that provides a reference current to said control terminal when the control terminal is decoupled from said programmable voltage source, a comparator that senses a voltage difference between said programmable voltage source and said control terminal, and a timer coupled to an output of the comparator. The timer measures a time period required to increase the control terminal voltage. The capacitance of the actuator may be determined and used to calibrate the position of a lens.

Abstract: Embodiments of the present invention include techniques for charging a battery. In one embodiment, the present invention includes a method comprising determining if a maximum current output of a power source is above a threshold, configuring a regulator coupled to the power source, wherein the regulator is configured in a pass mode if the maximum current output is above the threshold, and wherein the regulator is configured in a regulation mode if the maximum current output is below the threshold, and generating pulses to a battery, wherein an output of the regulator is coupled to the battery when a pulse is being generated, and the output of the regulator is decoupled from the battery when a pulse is not being generated. In other embodiments, the techniques may be embodied in a circuit including a detection circuit and a switching regulator coupled to a battery through a pulse circuit.

Abstract: In one embodiment the present invention includes an over-current protection method. The method comprises generating a switching signal, starting and stopping a timer, sensing a current through a switch, comparing a response time to a reference time, and generating an over-current alarm signal. The switching signal activates one or more switches in a switching regulator. The timer is started in response to the switch being activated and is stopped in response to the sensed current exceeding a threshold. The response time indicates the time period between the starting and the stopping of the timer. The over-current alarm signal is generated if the response time is less than the reference time.

Abstract: Embodiments of the present invention include techniques for charging a battery using a switching regulator. Some embodiments include programmable switching battery chargers that can be configured using digital techniques. Other embodiments include switching battery chargers that modify the battery current based on sensed circuit conditions such as battery voltage or input current to the switching regulator. In one embodiment, the present invention includes a USB battery charger.

Abstract: A control loop system is provided that employs an active DC output control circuit that more accurately calibrates the desired voltage at a load, e.g. 3.3 volts, by adjusting a trim pin on a DC/DC converter.

Abstract: Embodiments of the present invention include an electronic circuit for performing current sensing. In one embodiment, the present invention includes a first switching transistor and a second switching transistor both coupled to receive a first switching current and a switching signal, and one or more transistors coupled in a first series. A first terminal of an initial transistor in the first series is coupled to a second terminal of the second switching transistor. A second terminal of a last transistor in the first series is coupled to a reference voltage. The first switching current is coupled to a second node between the second terminal of the second switching transistor and the first terminal of the initial transistor in the first series. In this manner, the circuit produces a switching voltage corresponding to said first switching current.

Abstract: Embodiments of the present invention include electronic circuits, systems, and methods for charging a battery. In one embodiment, the present invention includes a method, which may be implemented by an integrated circuit, comprising charging the battery using a constant current until the voltage on the battery increases to a first voltage level, and charging the battery using a constant voltage, wherein the constant voltage is set to a second voltage level. The constant current charging transitions to constant voltage charging when the voltage on the battery reaches the first voltage level, where the first voltage level is greater than the second voltage level.

Abstract: Embodiments of the present invention include techniques for sensing current. In one embodiment, a switch in a switching regulator is coupled to a power supply. Input current from the supply is translated into an output current of the switching regulator. A signal corresponding to the output current is generated. The signal is selectively turned off with the input switch is open. Accordingly, the signal tracks the input current into the regulator. The signal may be used to determine the input current. In one embodiment, the signal is a voltage signal generated by a current corresponding to the output current provided into a resistor.

Abstract: Embodiments of the present invention include an electronic circuit for performing current sensing. In one embodiment, the present invention includes a first switching transistor and a second switching transistor both coupled to receive a first switching current and a switching signal, and one or more transistors coupled in a first series. A first terminal of an initial transistor in the first series is coupled to a second terminal of the second switching transistor. A second terminal of a last transistor in the first series is coupled to a reference voltage. The first switching current is coupled to a second node between the second terminal of the second switching transistor and the first terminal of the initial transistor in the first series. In this manner, the circuit produces a switching voltage corresponding to said first switching current.

Abstract: In one embodiment the present invention includes a method of controlling a switching regulator based on a derived input current. In one embodiment, an output current of said switching regulator is detected and used to generate a first voltage or current signal corresponding to the output current. Additionally, a switching signal of said switching regulator is detected and used to generate a second voltage or current signal corresponding to the switching signal. The resulting signals may be combined to produce a voltage or current signal corresponding to an input current of said switching regulator. The switching signal may be modified based on the derived voltage or current signal and used to control the system.

Abstract: Embodiments of the present invention include techniques for charging a battery. In one embodiment, the present invention includes a method comprising determining if a maximum current output of a power source is above a threshold, configuring a regulator coupled to the power source, wherein the regulator is configured in a pass mode if the maximum current output is above the threshold, and wherein the regulator is configured in a regulation mode if the maximum current output is below the threshold, and generating pulses to a battery, wherein an output of the regulator is coupled to the battery when a pulse is being generated, and the output of the regulator is decoupled from the battery when a pulse is not being generated. In other embodiments, the techniques may be embodied in a circuit including a detection circuit and a switching regulator coupled to a battery through a pulse circuit.

Abstract: In one embodiment the present invention includes a method of charging a battery comprising storing a plurality of charging parameters in one or more programmable data storage elements. The charging parameters may be used to program a variety of battery charging parameters including constant currents, voltages, thresholds, timers, or temperature controls. In one embodiment, the present invention includes a software algorithm that changes the charging parameters to improve battery charging efficiency.

Abstract: A system and method is provided to accomplish distributed power sequencing function of a large electronics system with minimum number of signals in the sequencing network without compromising the flexibility and expandability. In one embodiment of the invention, the power sequencing function is accomplished with two signals of the sequencing network: power_on/power_off signal and SEQ_LINK signal. The power_on/power_off signal controls whether the sequencing is in power_on mode for turning on power to multiple devices in a predetermined sequence or power_off mode for for turning off power to multiple devices in a reverse sequence. The SEQ_LINK signal controls when the sequence counters, located in each participating device, are allowed to count to the subsequent state. Each sequencing logic circuit of these participating devices responds to a predetermined sequence position to enable the power on or power off of the power supply it controls.