Abstract: An enabling circuit for enabling a DC-DC converter having a capacitor coupled to an output terminal of the DC-DC converter to be controlled by a control signal. The enabling circuit may include a comparison circuit configured to compare a feedback signal representative of a charge on the capacitor with a signal representative of a reference charge and to provide an output to in response to the comparison to enable the DC-DC converter to be controlled by the control signal if the charge on the capacitor is less than the reference charge. The enabling circuit may also include a discharge path configured to discharge the charge on the capacitor if the charge is greater than the reference charge. A related system and method are also provided.

Abstract: An analog to digital converter (ADC) includes a cross switch array coupled between an input switch array and an integrator configured to alternately transfer charges from a first input capacitor and a second input capacitor to a first integration capacitor and a second integration capacitor thereby improving linearity problems caused by capacitor mismatching. The cross switch array may also be configured to transfer charges from the first input capacitor to the first integration capacitor and from the second input capacitor to the second integration capacitor during a first charge transfer time interval, and from the first input capacitor to the second integration capacitor and from the second input capacitor to the first integration capacitor during a second charge transfer time interval. A sensing system including and ADC consistent with the invention is also provided. Various methods of transferring charges in an ADC are also provided.

Abstract: 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.

Abstract: A method includes starting a time count of a time interval at a start of a state change of a switch of a DC to DC converter; monitoring if the switch is in a skip mode; and disabling the skip mode in response to an expiration of the time interval so that the switch changes states at a frequency rate greater than an audible frequency for humans.

Abstract: A dual mode smart card controller is provided. In one embodiment, a USB and ISO7816 smart card controller is provided that determines the type of card that is inserted into a slot. If the smart card is a USB smart card, the controller is adapted to pass control of the smart card to an external PC host USB hub circuit. If the smart card is an ISO7816 card, then control is handled by the dual mode controller. In another embodiment, the controller includes an embedded USB hub circuit to permit the controller to directly control both USB and ISO7816 smart cards. Exemplary control sequencing includes monitoring a C4 signal line for a preselected time period, or generating an enable signal if a USB smart card is detected.

Abstract: The present invention provides an inverter controller comprising a drive circuit that generates a plurality of switch drive signals for inverter applications. In some exemplary embodiments, the drive circuit operates by reversing the command level of an error signal. In other embodiments, the drive circuit operates by using a half period of a sawtooth signal. In still other embodiments, the drive circuit operates by using a double period opposite shifting pulses method. The present invention also provides a PWM signal generator circuit that generates periodic PWM switch drive signals symmetrical to the minimum or maximum of a sawtooth waveform.

Abstract: An inverter controller for an LCD panel display with automatic brightness adjustment circuitry is provided. In one exemplary embodiment, the controller includes a look-up table that receives a signal indicative of the ambient light around the LCD panel and generates a signal corresponding to desired panel brightness. The signal corresponding to the desired panel brightness is, in turn, used as a threshold signal in a conventional feedback inverter topology supplying power to lamps associated with the LCD panel. In another exemplary embodiment, a master controller is provided that includes a light sensor controller to poll a slave light sensor to generate a signal indicative of the ambient light around the LCD panel.

Abstract: Power control circuitry and method for controlling a variable output DC power source. The power control circuitry may comprise a first comparator to compare a signal representative of an output current level of the variable output DC power source with a threshold level and provide a first output signal in response to the comparison. The power control circuitry may further comprise threshold input circuitry to provide the threshold level to the first comparator, the threshold level being a fixed threshold level if an output voltage of the variable output DC power source is less than or equal to a first fixed voltage level, the threshold level being a variable threshold level if the output voltage is greater than the first fixed voltage level.

Abstract: Full capacity determination in a battery gas gauge. Operations include measuring instantaneous open circuit voltage levels during an open circuit time interval for a specific battery cell and correlating such measurements to estimate values. Such estimated values may then be correlated to associated relative state of charge levels. Finally, a full capacity calculation can be made based on the associated relative state of charge levels. A plurality of full capacity determinations may also be made and compared to each other to assess the reliability of such determinations.

Abstract: A cardbus controller is provided that reduces signal count and board area. In one exemplary embodiment, the controller is adapted to multiplex selected signals in a two PC Card system so that signal lines are not repeated. The selected signals may include common signals between two PC Cards. The controller may also include early detection circuitry, arbitration circuitry and power management circuitry to more effectively operate two PC Cards. In other exemplary embodiments, the invention provides a method of reducing the chip area of a PC Card controller integrated circuit by mapping an internal IDSEL signal to an external address line.

Abstract: An integrated controller for the detection and operation of both PC Cards, smart cards and passive smart card adapter cards. In one aspect, the invention detects the presence of standard expansion cards or passive smart card adapters by utilizing the reserved detection and voltage selection signal area defined by the PC Card specification. In another aspect, the invention provides an integrated controller that includes logic to operate either a standard expansion card or a passive smart card adapter by reassigning certain PC Card signal lines to operate a standard expansion card or a passive smart card adapter, thereby eliminating the need to provide pins in addition to those defined by the PC Card specification.

Abstract: 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.

Abstract: 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.

Abstract: A reconfigurable flash media reader system provides a flash media reader that accepts both asynchronous and synchronous flash media cards. The reader identifies the card type of the inserted flash media card and notifies the host computer of the card type. The host computer has a list of interface information for different types of flash media cards and references the card type in the list and sets the proper baud rate on the reader. If the flash media card is a synchronous card, data that is to written into the flash media card is gathered and converted to the proper card IO strobes for the card type which are interleaved with the proper card clock strobes for the card type into a bit stream in a bulk transfer packet. The reader extracts the data bit stream from said bulk transfer packet and clocks the data bit stream into the flash media card using the baud rate as a reference clock.

Abstract: A power management PC expansion card controller that includes power on reset circuitry to reset power management enable registers during a reset period, thereby ensuring that the PME registers correctly identify the power management capabilities of the controller. Once the PME registers are reset, an instruction may be provided to change the state of the registers from a default reset state to a state that supports advanced power management capabilities, for example wake-up functions. Additionally, the controller includes blocking circuitry to block conventional reset signals from resetting the power management and proprietary registers if the PME register is instructed to change states, thereby preserving the data contained in the power management and proprietary registers against future reset events.

Abstract: A cordless power tool may include tool identification circuitry to provide a tool identification signal to a battery pack. The tool identification signal may be representative of data particular to the cordless power tool. A method may include coupling a battery pack to a cordless power tool, and providing a tool identification signal to the battery pack from the cordless power tool once the battery pack is coupled to the cordless power tool, the tool identification signal representative of data particular to the cordless power tool.

Abstract: An integrated circuit inverter controller that includes at least one input pin that is configured to receive two or more input signals. The input pin may be multiplexed so that the appropriate input signal is directed to appropriate circuitry within the controller to support two or more functions of the controller. Alternatively, the input signals may be present in differing time periods so that a single pin can support two or more functions. Multifunctional or multitasked pins reduce the overall pin count of the inverter controller.

Abstract: An enabling circuit for enabling a DC—DC converter having a capacitor coupled to an output terminal of the DC—DC converter to be controlled by a control signal. The enabling circuit may include a comparison circuit configured to compare a feedback signal representative of a charge on the capacitor with a signal representative of a reference charge and to provide an output to in response to the comparison to enable the DC—DC converter to be controlled by the control signal if the charge on the capacitor is less than the reference charge. The enabling circuit may also include a discharge path configured to discharge the charge on the capacitor if the charge is greater than the reference charge. A related system and method are also provided.

Abstract: A DC to DC converter includes a comparator, a driver, and a pair of switches. The comparator compares the output voltage with a reference voltage signal and generates a PWM signal. The driver drives the switches so as to force the output voltage to follow the reference signal. In a multiphase architecture, two or more such converter circuits are incorporated to minimize the output voltage ripple and further reduce the recovery time. In a two-phase architecture, two reference signals are phase-shifted by 180 degrees. In an N-phase architecture, the reference signals are phase-shifted by 360/N degrees.

Abstract: A method includes starting a time count of a time interval at a start of a state change of a switch of a DC to DC converter; monitoring if the switch is in a skip mode; and disabling the skip mode in response to an expiration of the time interval so that the switch changes states at a frequency rate greater than an audible frequency for humans.