Abstract: The present invention provides a GPS receiver which is capable of computing a local time reference without employing a RTC circuitry and employing a nonvolatile storing unit to store backup navigation data, wherein the local time reference and the backup navigation data can be used to reduce the TTFF of the GPS receiver. The GPS receiver includes a nonvolatile storing unit and a positioning unit. The positioning unit is capable of retrieving the backup navigation data from the nonvolatile storing unit and computing a local time reference after said GPS receiver is powered up. The positioning unit is further capable of employing the backup navigation data and the local time reference to computing the position of the GPS.

Abstract: A method for using a single pin to support both power input and power control functions for an integrated circuit, wherein the integrated circuit is in communication with a system. The method includes receiving at the pin a power input signal from the system, generating a power control signal based on the power input signal through a control signal generating circuit, and sending the power control signal to the integrated circuit.

Abstract: An apparatus and method for detecting battery pack voltage is disclosed. The voltage detection apparatus includes a plurality of selectors for providing a cell voltage of a predetermined cell, a detector buffer for receiving the cell voltage of the predetermined cell and supplying an intermediate voltage, a data process circuit for processing the intermediate voltage to acquire a voltage value indicative of the cell voltage of the predetermined cell, wherein each selector includes a plurality of switches and a plurality of level shifters, each switch being controlled by one of the plurality of level shifters to operate with a safe gate-source voltage, source-bulk voltage and reverse-biased body diode.

Abstract: An analog to digital converter (ADC) with interference rejection capability and method thereof are disclosed. The ADC includes a threshold generator, a comparator circuit, a counter and an integrator. By comparing a signal with positive and negative threshold signals from the threshold generator, the comparator circuit converts the signal from analog to digital based on the result of the comparison. The counter counts a percentage of the digital signal and generates a bit signal based on the counted percentage. In response to the bit signal, the integrator supplies a control signal to the threshold generator to regulate the positive and negative threshold signals so as to maintain the counted percentage at a predetermined percentage threshold.

Abstract: The present invention is a LDO voltage regulator circuit with common-mode feedback. The LDO voltage regulator includes an error amplifier with a common-mode feedback unit, a pass device and a compensation circuit. A signal from the pass device acts as an input signal to the error amplifier and is compared with another input signal, producing a differential signal. The differential signal is amplified and then provided to the pass device. A capacitor in the compensation unit provides frequency compensation to the LDO voltage regulator. The common-mode feedback unit incorporated into the error amplifier greatly improves a slew rate of a gate voltage of the pass device.

Abstract: A computer subsystem of a computer includes a CPU, RAM, display, storage device, input device(s), and a digital-audio generating IC. A CD-ROM subsystem of the computer includes a CD-ROM drive and CD-ROM control buttons for controlling CD-ROM drivers operation while playing audio CDs. An audio-interface IC of the CD-ROM subsystem couples a bus of the computer subsystem to the CD-ROM drive, and to the control buttons. The audio-interface IC, in one operating mode, relays commands and data between the bus and the CD-ROM drive. A second operating mode permits turning the computer subsystem off while the audio-interface IC autonomously responds to the control buttons and transmits commands to the CD-ROM drive for playing an audio CD.

Abstract: A DC-DC converter for converting DC power received from a high-voltage DC power supply to a well-regulated output voltage that is significantly lower than the received voltage. The converter includes a regulated voltage-reduction stage which receives high-voltage DC electrical power and supplies DC electrical power at a voltage which is lower than that received. The converter also includes a separately regulated electrically isolated stage, energized by electrical power received from the voltage-reduction stage, that supplies DC electrical power to a load at the significantly lower output voltage. A feedback circuit couples an output signal from the output of the isolation-stage for regulating operation of the voltage-reduction stage and of the isolation stage.

Abstract: An active transient-control circuit included in a power supply responds swiftly to changes occurring in the output-power voltage produced by a power converter to reduce transient changes in the output-power voltage caused by sudden, substantial changes in the electrical current drawn by the load. To respond in this way, when the output-power voltage has a magnitude less than a lower pre-established-voltage threshold, the active transient-control circuit supplies electrical energy directly to the load from the input electrical power thereby augmenting output electrical power supplied to the load by the power converter. Correspondingly, when the output-power voltage has a magnitude that exceeds an upper pre-established-voltage threshold, the active transient-control circuit draws electrical energy directly from the output of the power converter.

Abstract: A computer subsystem of a computer includes a CPU, RAM, display, storage device, input device(s), and a digital-audio generating IC. A CD-ROM subsystem of the computer includes a CD-ROM drive and CD-ROM control buttons for controlling CD-ROM drive's operation while playing audio CDs. An audio-interface IC of the CD-ROM subsystem couples a bus of the computer subsystem to the CD-ROM drive, and to the control buttons. The audio-interface IC, in one operating mode, relays commands and data between the bus and the CD-ROM drive. A second operating mode permits turning the computer subsystem off while the audio-interface IC autonomously responds to the control buttons and transmits commands to the CD-ROM drive for playing an audio CD.

Abstract: A battery charger IC for controlling operation of a buck converter circuit that includes a series switch and a resistor for sensing battery charging current. The battery charger IC includes a pulse-width-modulation switch drive circuit that, during charging of the battery, supplies to the buck converter circuit with an electrical signal which repeatedly turns-on and then turns-off the series switch. The battery charger IC also includes a charging-current sense amplifier which receives from the current-sensing resistor and amplifies an electrical signal which represents the battery charging electrical current. The charging-current sense amplifier includes a bridge circuit to which is coupled the electrical signal received by the charging-current sense amplifier from the current-sensing resistor and an auto-zero circuit.

Abstract: A controller for a smart battery selector included in a portable device has a plurality of switch-drivers at least equal to a plurality of smart batteries. The batteries provide battery-state data via a bus to a host computer included in the portable device. Each switch-driver effects selection of an associated battery. A control electronic-circuit in the controller directs operation of the switch-drivers for selecting the battery so that at any instant only one battery powers the portable device. A bus-snooper circuit permits the controller to independently monitor the bus for battery-condition alarm-messages. The controller may respond to such messages by selecting a different battery. The controller may also select a single battery for recharging, and may terminate charging upon receiving a battery overcharge message.