Abstract: A sensor interface includes on-chip relaxation oscillator circuit and a PLL that operate cooperatively to generate a highly accurate clock signal on-chip using low-power components. A photodiode generates a current signal based on an optical signal that is representative of a sensor signal. An ADC that operates based on the highly accurate clock signal generates a digital signal based on the current signal generated by the photodiode, and a processor processed the digital signal to estimate sensor data within the sensor signal. Examples of characteristics that may be sensed can include environmental characteristics (e.g., temperature, humidity, barometric pressure, etc.) and/or biomedical characteristics (e.g., body temperature, heart rate, respiratory rate, blood pressure, etc.). If desired, an amplifier processes the photodiode-provided current signal before it is provided to the ADC. Also, one or more CDACs that generate feedback currents may be used to reduce noise sensitivity of the sensor interface.

Abstract: Systems and methods are disclosed to provide automatic power control for a driver circuit. Embodiments disclosed herein enable a driver circuit to automatically decrease the gain of amplified input signals when output power exceeds a threshold. Further, embodiments disclosed herein enable a driver circuit to automatically increase the gain of amplified input signals when battery supply voltage drops to avoid unwanted output signal distortion. By using reference signals for battery power and amplified signal input, the amplifiers of the driver circuit can be automatically adjusted until an equilibrium is reached.

Abstract: A sensor interface includes on-chip relaxation oscillator circuit and a PLL that operate cooperatively to generate a highly accurate clock signal on-chip using low-power components. A photodiode generates a current signal based on an optical signal that is representative of a sensor signal. An ADC that operates based on the highly accurate clock signal generates a digital signal based on the current signal generated by the photodiode, and a processor processed the digital signal to estimate sensor data within the sensor signal. Examples of characteristics that may be sensed can include environmental characteristics (e.g., temperature, humidity, barometric pressure, etc.) and/or biomedical characteristics (e.g., body temperature, heart rate, respiratory rate, blood pressure, etc.). In desired, an amplifier processes the photodiode-provided current signal before it is provided to the ADC. Also, one or more CDACs that generate feedback currents may be used to reduce noise sensitivity of the sensor interface.

Abstract: Systems and methods are disclosed to provide automatic power control for a driver circuit. Embodiments disclosed herein enable a driver circuit to automatically decrease the gain of amplified input signals when output power exceeds a threshold. Further, embodiments disclosed herein enable a driver circuit to automatically increase the gain of amplified input signals when battery supply voltage drops to avoid unwanted output signal distortion. By using reference signals for battery power and amplified signal input, the amplifiers of the driver circuit can be automatically adjusted until an equilibrium is reached.

Abstract: Aspects of a method and system for compensating temperature readings from a temperature sensing crystal integrated circuit are provided. An electronic device may digitize a temperature indication received from a temperature sensing circuit, digitize one or more calibration voltages received from said temperature sensing circuit, and calculate a compensated temperature indication utilizing the digitized calibration voltage(s), and the digitized temperature indication, and data from a table that characterizes behavior of the temperature sensing circuit as a function of temperature. One or more circuits in the electronic device may be controlled based on the compensated temperature indication. The compensated temperature indication may compensate for a gain error and/or offset error of a digital to analog converter that digitizes the temperature indication and the calibration voltage(s). There may be two calibration voltages.

Abstract: Aspects of a method and system for a temperature sensing crystal Integrated circuit with digital temperature output are provided. In this regard, an indication of temperature may be generated in an integrated circuit (IC) comprising a memory, a crystal or crystal oscillator, and at least a portion of an analog-to-digital converter. The temperature indication may be digitized via the analog-to-digital converter. Operation of one or more circuits may be controlled based on the digital temperature indication. The digital temperature indication may be communicated over a communication bus. An analog portion of the analog-to-digital converter may be integrated in the IC and may comprise, for example, a delta-sigma modulator. A digital portion of the analog-to-digital converter may be external to the IC and may comprise, for example, a digital filter.

Abstract: Aspects of a method and system for compensating temperature readings from a temperature sensing crystal integrated circuit are provided. An electronic device may digitize a temperature indication received from a temperature sensing circuit, digitize one or more calibration voltages received from said temperature sensing circuit, and calculate a compensated temperature indication utilizing the digitized calibration voltage(s), and the digitized temperature indication, and data from a table that characterizes behavior of the temperature sensing circuit as a function of temperature. One or more circuits in the electronic device may be controlled based on the compensated temperature indication. The compensated temperature indication may compensate for a gain error and/or offset error of a digital to analog converter that digitizes the temperature indication and the calibration voltage(s). There may be two calibration voltages.

Abstract: Aspects of a method and system for compensating temperature readings from a temperature sensing crystal integrated circuit are provided. In this regard, a temperature indication and calibration voltages from a temperature sensing crystal integrated circuit (TSCIC) may be digitized and the digital signals may be utilized to calculate a compensated temperature indication. Data derived from a memory integrated within the TSCIC may be retrieved based on the compensated temperature indication. The retrieved data may be utilized to control operation of one or more circuits. The compensated temperature indication may be calculated by removing a gain error and/or offset error from the digitized temperature indication. The compensated temperature indication may be utilized as an index for a data table. The compensated temperature indication may be a normalized compensated temperature indication. The calibration voltages may include a minimum voltage and/or a maximum voltage that the TSCIC is operable to output.