Abstract: An apparatus and method measure a temperature of a temperature sensing element having a temperature dependent resistance based on a ratio of discharge times of a capacitor through a reference resistance and through the combination of the reference resistance in parallel with the temperature sensing element is disclosed. A reference discharge time is determined by measuring the discharge time of the capacitor from a first voltage to a second voltage through a reference resistance. A temperature evaluation discharge time is determined by measuring the time to discharge the capacitor from the first voltage to the second voltage through the reference resistance in parallel with the temperature sensing element. The ratio of the temperature evaluation discharge time to the reference discharge time is used to determine the temperature and produce a digital representation of the temperature.

Abstract: A switch de-bouncing device includes a majority counter that counts samples generated by a sampler sampling a switch output where a counter value is incremented for each sample indicating a first switch state and decremented for each sample indicating a second switch state of the switch. A controller determines that the switch is in the first switch state when the counter value is above a first state threshold and is in the second switch state when the counter value is below a second state threshold.

Abstract: An apparatus and method measure a temperature of a temperature sensing element having a temperature dependent resistance based on a ratio of discharge times of a capacitor through a reference resistance and through the combination of the reference resistance in parallel with the temperature sensing element is disclosed. A reference discharge time is determined by measuring the discharge time of the capacitor from a first voltage to a second voltage through a reference resistance. A temperature evaluation discharge time is determined by measuring the time to discharge the capacitor from the first voltage to the second voltage through the reference resistance in parallel with the temperature sensing element. The ratio of the temperature evaluation discharge time to the reference discharge time is used to determine the temperature and produce a digital representation of the temperature.

Abstract: An apparatus, system, and method provide device identification and temperature sensing of a device with a temperature sensing circuit (TSC) within the device. The TSC includes a temperature sensing element (TSE) connected in parallel with a voltage clamping network (VCN) that limits the voltage across the TSE to an identification voltage within an identification voltage range when the voltage is greater than or equal to a lower voltage of the identification voltage range. When a voltage below the lower range is applied to the TSC, the VCN appears as an open circuit and the resistance of the TSC corresponds to temperature. For cost or other concerns, a first TSC may omit the VCN to provide a maximum identification voltage and other TSCs may include VCNs with lower identification voltage ranges.

Abstract: A switch de-bouncing device includes a majority counter that counts samples generated by a sampler sampling a switch output where a counter value is incremented for each sample indicating a first switch state and decremented for each sample indicating a second switch state of the switch. A controller determines that the switch is in the first switch state when the counter value is above a first state threshold and is in the second switch state when the counter value is below a second state threshold.

Abstract: An apparatus and method measure a temperature of a temperature sensing element having a temperature dependent resistance based on a ratio of discharge times of a capacitor through a reference resistance and through the combination of the reference resistance in parallel with the temperature sensing element is disclosed. A reference discharge time is determined by measuring the discharge time of the capacitor from a first voltage to a second voltage through a reference resistance. A temperature evaluation discharge time is determined by measuring the time to discharge the capacitor from the first voltage to the second voltage through the reference resistance in parallel with the temperature sensing element. The ratio of the temperature evaluation discharge time to the reference discharge time is used to determine the temperature and produce a digital representation of the temperature.

Abstract: A retractable visual display is movable along a longitudinal axis of the visual display from a retracted position within the device housing of the portable communication device to an extended position where at least a portion of the visual display is exposed outside of the device housing in the extended position. The visual display is off when retracted and power is supplied to the visual display only in the extended position although the communication functions are active when the visual display is retracted within the device housing. In some circumstances, a secondary display presents limited information when the visual display is retracted.

Abstract: An apparatus, system, and method provide device identification and temperature sensing of a device with a temperature sensing circuit (TSC) within the device. The TSC includes a temperature sensing element (TSE) connected in parallel with a voltage clamping network (VCN) that limits the voltage across the TSE to an identification voltage within an identification voltage range when the voltage is greater than or equal to a lower voltage of the identification voltage range. When a voltage below the lower range is applied to the TSC, the VCN appears as an open circuit and the resistance of the TSC corresponds to temperature. For cost or other concerns, a first TSC may omit the VCN to provide a maximum identification voltage and other TSCs may include VCNs with lower identification voltage ranges.

Abstract: A level shifting multiplexing circuit provides an interface between a two conductor full duplex bus (two conductor bus) and a single conductor bidirectional half duplex bus (single conductor bus) where the two conductor bus is operates at a first supply voltage and the single conductor bus operates at a second supply voltage. A first switching circuit connected between the single conductor bus and the reception conductor of the two conductor bus is configured to provide a low logic signal to the reception conductor when a first switching voltage threshold is exceeded and to provide a high logic signal, otherwise. A second switching circuit connected between the single conductor bus and the transmission conductor of the two conductor bus is configured to provide a voltage less than the first switching voltage threshold when voltage at the transmission conductor exceeds a second switching voltage threshold unless a high logic signal is received on the single conductor bus.

Abstract: A keypad assembly comprising a substrate, a membrane, and a logic component. The substrate has at least one set of electrical contact points that comprise a first, second, and a third conductive electric-contact area. The membrane comprises domed elements having a conductive elements fixedly attached thereto. Each conductive element is configured to interface with one or more of the electrical contact points with a soft press and a hard press. The logic component is in operative communication with the substrate and the membrane. The logic component is configured to distinguish between the soft press and the hard press.