Abstract: A number of illustrative variations may include a method, which may include obtaining terminal voltage data of a electrochemical device; determining an equivalent circuit model which operates in a manner approximating the terminal voltage data comprising an open circuit voltage VOC comprising a constant voltage source V0 and a voltage Vs across a capacitor Cs, in series with an overpotential circuit comprising an overpotential voltage V1; determining at least one of the power capabilities of the equivalent circuit model; and, estimating at least one of the power capabilities of the electrochemical device based upon the determined power capabilities of the equivalent circuit model.

Abstract: A number of illustrative variations may include a method, which may include obtaining terminal voltage data of a electrochemical device; determining an equivalent circuit model which operates in a manner approximating the terminal voltage data comprising an open circuit voltage VOC comprising a constant voltage source V0 and a voltage Vs across a capacitor Cs, in series with an overpotential circuit comprising an overpotential voltage V1; determining at least one of the power capabilities of the equivalent circuit model; and, estimating at least one of the power capabilities of the electrochemical device based upon the determined power capabilities of the equivalent circuit model.

Abstract: Bandgap voltage reference circuitry capable of operating at very low power supply voltages. The current source for driving the core bandgap voltage reference is implemented with insulated gate field effect transistors having low threshold voltages. Voltage clamp circuitry protects the transistors from power supply voltage variations rising above a predetermined clamp voltage. An output amplifier with output biasing circuitry having a circuit structure similar to that of the core bandgap voltage reference ensures that the bandgap reaches the intended steady state of operation.

Abstract: A voltage regulation and battery charging system is provided. The system can simultaneously provide a regulated output voltage and charge a battery. The system includes a battery charger circuit, a voltage regulator circuit, and a voltage tracking circuit. A voltage divider is used to provide the voltage regulator circuit with a feedback voltage from the output voltage. Further, the voltage tracking circuit is operable to draw current from the voltage divider such that the regulated output voltage tracks the battery voltage if the battery voltage is above a threshold voltage. The voltage tracking circuit includes an op amp, a current mirror, and a resistor that is coupled between the inverting input of the op amp and the battery. The noninverting input of the op amp receives the threshold voltage. Additionally, the output of the op amp is coupled to the gates of the transistors in the current mirror.

Abstract: A voltage regulation and battery charging system is provided. The system may include a switching regulator selection control circuit, two switching regulator controller circuits, two power transistors, a common synchronous transistor, and a common LC circuit. The two switching regulator controller circuits may synchronously switch the two power transistors and the one common synchronous transistor. One of the switching regulator controller circuits may receive a voltage from an AC adapter and the other may receive a voltage from a USB port. Further, the switching regulation selection control circuit selects which of the two switching regulator controller circuits controls the regulation of the system output voltage employing the common LC filter.

Abstract: Circuitry for powering a load and charging of a battery from a power source by a smart power supply is provided. The smart power supply controls the maximum current for battery charging based in part upon variables such as the maximum rate of charge of the battery and maximum source current. The smart power supply is thus capable of providing the power requested by the load, and use the remaining power for battery charging.

Abstract: A circuit for regulating a sensed current in a power transistor is provided. The circuit is configured to sense if the drain current of the power transistor has reached a limit current Ilimit. A sense transistor is arranged in an m:1 current mirror relationship with the power transistor. Additionally, a current sink that is coupled to the drain of the sense current is also configured to sink a current approximately equal to Ilimit/m. Further, a comparison circuit is configured to compare the drain voltages of the power and sense transistors. Also, if the drain current of the power transistor is less than Ilimit, a current sink pulls down the drain of the sense transistor, so that the drain voltage of the sense transistor is less than the drain voltage of the power transistor. However, if the level of the drain current of the power transistor reaches Ilimit, then Vds of the sense transistor would reach Vds of the power transistor, and the comparator would trip.

Abstract: A polysilicon fuse trim read cell utilizes a fuse structure in a single bit memory cell. When the fuse structure is blown, the memory cell can be read and its stored value retained as a digital output. The cell uses no power in the steady state.

Abstract: A band-gap filter circuit is disclosed for use in a voltage regulator. A capacitor charger (or “cap charger”) circuit quickly charges a filter capacitor when power is applied to the voltage regulator circuit. At start-up, the cap charger begins charging the filter capacitor. Once an output node equals or nearly equals the voltage at the input node, the cap charger shuts off. The circuit provides a very fast turn-on time, reaching 95% of its steady state value within 200 microseconds, thus overcoming the long turn-on times associated with other designs. The present invention may be utilized in power sensitive applications, such as cellular telephones, that wish to shut off the voltage regulator in order to conserve power.