Abstract: Embodiments of power-on reset (POR) circuits are described. In one embodiment, a POR circuit includes a primary ladder circuit connected to a supply voltage and configured to generate a reference signal for a reset signal in response to the supply voltage and a secondary ladder circuit connected to the supply voltage and configured to bias the primary ladder circuit in response to the supply voltage.

Abstract: One example discloses a voltage converter, comprising: an input configured to receive a first voltage from a battery; an output configured to provide a second voltage to a load; a controller configured to reduce a battery current received from the battery if the first voltage received from the battery is below a first threshold voltage.

Abstract: Various embodiments relate to a mode detector configured to determine a mode of a circuit based upon an attached power source, including: a first latch configured to hold an first input value and output the first held value and an inverse of the first held value; a second latch configured to hold a second input value and output the second held value and an inverse of the second held value; a first output switch connected between a first power source line and a power source output of the mode detector, wherein the first output switch is configured to be controlled by the output of the first latch; a second output switch connected between a second power source line and the power source output of the mode detector, wherein the second output switch is configured to be controlled by the output of the second latch; a first AND gate with a first input and a second input connected to the inverse output of the second latch, wherein the first input is configured to receive a first power on reset signal based upon the f

Abstract: Various embodiments relate to a mode detector configured to determine a mode of a circuit based upon an attached power source, including: a first latch configured to hold an first input value and output the first held value and an inverse of the first held value; a second latch configured to hold a second input value and output the second held value and an inverse of the second held value; a first output switch connected between a first power source line and a power source output of the mode detector, wherein the first output switch is configured to be controlled by the output of the first latch; a second output switch connected between a second power source line and the power source output of the mode detector, wherein the second output switch is configured to be controlled by the output of the second latch; a first AND gate with a first input and a second input connected to the inverse output of the second latch, wherein the first input is configured to receive a first power on reset signal based upon the f

Abstract: A method for accurately measuring a battery temperature using a temperature sensor embodied in a battery monitoring integrated circuit is disclosed. The method includes performing calibration to estimate a thermal resistance between the battery monitoring integrated circuit and a terminal of a battery, measuring a temperature using the temperature sensor, measuring a voltage at the terminal or at a supply pin of the battery monitoring integrated circuit while a current is being used to charge or discharge the battery, calculating a power by multiplying the voltage and the current, and calculating a self-heating temperature adjustment to the temperature by multiplying the power and the thermal resistance.

Abstract: An open wire detection system and method are provided. A semiconductor device includes a first diode having an anode terminal coupled to a first terminal and a cathode terminal coupled to a second terminal. The first and second terminals are configured for connection to a first battery cell terminal by way of a first conductive path and a second conductive path. A detect circuit is coupled to the first diode and is configured to provide a first open wire indication when a first voltage across the first diode exceeds a first threshold.

Abstract: A light emitting diode (LED) lighting system for an automobile includes a switch block, a capacitor, a charge pump, and a capacitor detector. The charge pump includes an output to provide power to a gate driver of the switch block at a nominal voltage level. The capacitor detector circuit includes a detector input and a detector output. The detector input is connected to the charge pump output and to the charge pump capacitor to detect a voltage level on the charge pump capacitor. The capacitor detector circuit provides a first indication on the detector output that the charge pump capacitor is present and undamaged when the voltage level is greater than the nominal voltage level. The capacitor detector circuit further provides a second indication on the detector output that the charge pump capacitor is not present or is damaged when the voltage level is less than the nominal voltage level.

Abstract: A method for accurately measuring a battery temperature using a temperature sensor embodied in a battery monitoring integrated circuit is disclosed. The method includes performing calibration to estimate a thermal resistance between the battery monitoring integrated circuit and a terminal of a battery, measuring a temperature using the temperature sensor, measuring a voltage at the terminal or at a supply pin of the battery monitoring integrated circuit while a current is being used to charge or discharge the battery, calculating a power by multiplying the voltage and the current, and calculating a self-heating temperature adjustment to the temperature by multiplying the power and the thermal resistance.

Abstract: A light emitting diode (LED) lighting system for an automobile includes a switch block, a capacitor, a charge pump, and a capacitor detector. The charge pump includes an output to provide power to a gate driver of the switch block at a nominal voltage level. The capacitor detector circuit includes a detector input and a detector output. The detector input is connected to the charge pump output and to the charge pump capacitor to detect a voltage level on the charge pump capacitor. The capacitor detector circuit provides a first indication on the detector output that the charge pump capacitor is present and undamaged when the voltage level is greater than the nominal voltage level. The capacitor detector circuit further provides a second indication on the detector output that the charge pump capacitor is not present or is damaged when the voltage level is less than the nominal voltage level.

Abstract: An open wire detection system and method are provided. A semiconductor device includes a first diode having an anode terminal coupled to a first terminal and a cathode terminal coupled to a second terminal. The first and second terminals are configured for connection to a first battery cell terminal by way of a first conductive path and a second conductive path. A detect circuit is coupled to the first diode and is configured to provide a first open wire indication when a first voltage across the first diode exceeds a first threshold.

Abstract: A power converter, configured to convert AC mains power to a DC output voltage which is lower than the AC mains' peak voltage, is disclosed. It comprises: a capacitor configured to store charge at a voltage range which is intermediate the peak voltage and the DC output voltage; a gated rectification stage comprising a rectifier for rectifying an AC mains power, and at least one switch configured to supply the rectified AC mains power to the capacitor during only a low-voltage part of a half-cycle of the AC mains; and a switched mode DC-DC power conversion stage comprising at least one further switch and configured to convert power from the capacitor to the DC output voltage during only a high-voltage part of the half-cycle. A controller for use in such a converter, and a corresponding method, are also disclosed.

Abstract: Disclosed is a controller for controlling a string of N LEDs connected in series and each having a current bypass switch in parallel therewith and configured to be supplied from a current source connected in series with the string of LEDs and being supplied by a supply voltage, the controller comprising: a respective bypass switch controller for each bypass switch and configured to control the respective bypass switch such that the respective LED has an on-period and an off-period, according to a common duty cycle; a phase control unit configured to set a respective timing of each of the bypass switches such that the fraction of LEDs not bypassed corresponds to the duty cycle; and a duty cycle adjustor configured to adjust the duty cycle, in dependence on the supply voltage. Associated methods and circuits are also disclosed.

Abstract: For an LED lighting application, overshoot-protection circuitry prevents an LED controller, such as a matrix lighting controller (MLC) that controls an array of LEDs, from falsely detecting an open-circuit condition in an LED controlled by the LED controller, by limiting the magnitude of an overshoot voltage (due to long-wire parasitic inductances) from occurring when a switch in the LED controller that is used to control the LED is turned off.

Abstract: An LED controller, for connecting to an LED string, comprising: an input terminal configured to receive a light-control-signal representative of a received-profile-identifier; a local memory configured to store a plurality of profile-data, wherein each of the plurality of profile-data defines an association between a plurality of light-values and a plurality of sequence-numbers; a processor configured to: determine one of the plurality of profile-data as selected-profile-data in accordance with the received-profile identifier; and determine a set of LED control signals for the LED string in accordance with light-values of the selected-profile-data for a set of sequence-numbers.

Abstract: Various methods, apparatuses and systems are directed to battery-charging applications. As may be consistent with one or more embodiments discussed herein, a charging current for charging a battery is modulated, and the frequency of the modulated charging current is set based upon an impedance of the battery. Temperature of the battery is estimated based upon the impedance exhibited by the battery, while the battery is charged with the modulated charging current. In various implementations, the battery charging rate is controlled based on the estimated temperature.

Abstract: Disclosed is a controller for controlling a string of N LEDs connected in series and each having a current bypass switch in parallel therewith and configured to be supplied from a current source connected in series with the string of LEDs and being supplied by a supply voltage, the controller comprising: a respective bypass switch controller for each bypass switch and configured to control the respective bypass switch such that the respective LED has an on-period and an off-period, according to a common duty cycle; a phase control unit configured to set a respective timing of each of the bypass switches such that the fraction of LEDs not bypassed corresponds to the duty cycle; and a duty cycle adjustor configured to adjust the duty cycle, in dependence on the supply voltage. Associated methods and circuits are also disclosed.

Abstract: An LED controller, for connecting to an LED string, comprising: an input terminal configured to receive a light-control-signal representative of a received-profile-identifier; a local memory configured to store a plurality of profile-data, wherein each of the plurality of profile-data defines an association between a plurality of light-values and a plurality of sequence-numbers; a processor configured to: determine one of the plurality of profile-data as selected-profile-data in accordance with the received-profile identifier; and determine a set of LED control signals for the LED string in accordance with light-values of the selected-profile-data for a set of sequence-numbers.

Abstract: A power converter, configured to convert AC mains power to a DC output voltage which is lower than the AC mains' peak voltage, is disclosed. It comprises: a capacitor configured to store charge at a voltage range which is intermediate the peak voltage and the DC output voltage; a gated rectification stage comprising a rectifier for rectifying an AC mains power, and at least one switch configured to supply the rectified AC mains power to the capacitor during only a low-voltage part of a half-cycle of the AC mains; and a switched mode DC-DC power conversion stage comprising at least one further switch and configured to convert power from the capacitor to the DC output voltage during only a high-voltage part of the half-cycle. A controller for use in such a converter, and a corresponding method, are also disclosed.

Abstract: Various methods, apparatuses and systems are directed to battery-charging applications. As may be consistent with one or more embodiments discussed herein, a charging current for charging a battery is modulated, and the frequency of the modulated charging current is set based upon an impedance of the battery. Temperature of the battery is estimated based upon the impedance exhibited by the battery, while the battery is charged with the modulated charging current. In various implementations, the battery charging rate is controlled based on the estimated temperature.

Abstract: The invention provides a cascode transistor circuit with a depletion mode transistor and a switching device. A gate bias circuit is connected between the gate of the depletion mode transistor and the low power line. The gate bias circuit is adapted to compensate the forward voltage of a diode function of the switching device. The depletion mode transistor and the gate bias circuit are formed as part of an integrated circuit.