Abstract: Disclosed are methods and circuits for detecting and recording timestamps for multiple events (222/322, 224/324) using a single input pin (252, 352) on a real time clock (RTC) (250, 350). Signals associated with each of the events are modulated to create a multiple level composite signal (240). The RTC includes a multiple signal level detection circuit to distinguish from among the various signal levels so that each event can be separately flagged and timestamped. For example, the opening of two or more covers (112, 114) on the housing (110) of an electronic device (100) can be monitored, distinguished, and separately flagged using a single RTC input port.

Abstract: Power supplies are switched in a manner that mitigates parasitic shorts. According to an example, a control circuit (e.g., 310) operates primary and backup power supplies using the higher of the primary and backup supply voltages, for switching between the power supplies.

Abstract: Switching power supplies are implemented using a variety of methods and devices. According to an example embodiment of the present invention, an arrangement provides power to a circuit by selecting between a first supply and a second supply. The arrangement includes a first circuit that charges a first capacitive element using the first supply and generates a first reference voltage by distributing charge between the first capacitive element and a second capacitive element. The arrangement also includes a first comparator that compares the first reference voltage to a second reference voltage derived from the second supply and a second comparator that compares the first reference voltage to a third reference voltage. The arrangement further includes a power control circuit that selects one of the supplies based on the results of the comparisons.

Abstract: Power supplies are switched in a manner that mitigates parasitic shorts. According to an example, a control circuit (e.g., 310) operates primary and backup power supplies using the higher of the primary and backup supply voltages, for switching between the power supplies.

Abstract: Disclosed are methods and circuits for detecting and recording timestamps for multiple events (222/322, 224/324) using a single input pin (252, 352) on a real time clock (RTC) (250, 350). Signals associated with each of the events are modulated to create a multiple level composite signal (240). The RTC includes a multiple signal level detection circuit to distinguish from among the various signal levels so that each event can be separately flagged and timestamped. For example, the opening of two or more covers (112, 114) on the housing (110) of an electronic device (100) can be monitored, distinguished, and separately flagged using a single RTC input port.

Abstract: Switching power supplies are implemented using a variety of methods and devices. According to an example embodiment of the present invention, an arrangement provides power to a circuit by selecting between a first supply and a second supply. The arrangement includes a first circuit that charges a first capacitive element using the first supply and generates a first reference voltage by distributing charge between the first capacitive element and a second capacitive element. The arrangement also includes a first comparator that compares the first reference voltage to a second reference voltage derived from the second supply and a second comparator that compares the first reference voltage to a third reference voltage. The arrangement further includes a power control circuit that selects one of the supplies based on the results of the comparisons.

Abstract: A method is for driving an output buffer for outputting a datum of a certain voltage level with a certain slew-rate as a function of an input datum and a first enabling signal. The first enabling signal commands the buffer to a normal functioning state or to a high impedance state. The output buffer has an output stage controlled at least by a pull-up driving circuit and a pull-down driving circuit, and an enabling circuit input with the input datum and a second enabling signal and generating control signals. The control signals may be in phase or in phase opposition depending on whether the second enabling signal is active or disabled, and they are input into the respective driving circuits.

Abstract: A method is for driving an output buffer for outputting a datum of a certain voltage level with a certain slew-rate as a function of an input datum and a first enabling signal. The first enabling signal commands the buffer to a normal functioning state or to a high impedance state. The output buffer has an output stage controlled at least by a pull-up driving circuit and a pull-down driving circuit, and an enabling circuit input with the input datum and a second enabling signal and generating control signals. The control signals may be in phase or in phase opposition depending on whether the second enabling signal is active or disabled, and they are input into the respective driving circuits.