Abstract: Disclosed herein are electronic devices, including wearable electronic devices, and components and configurations thereof, having one or more temperature sensors separated from the point of contact of the electronic device and an object, such as a user, whose temperature is being measured. In some embodiments, the electronic device includes both a temperature sensor and a light (visible, UV, and/or IR) emitter and sensor. Various embodiments are disclosed by which a temperature sensor may be shielded or separated from a light emitter/detector. A spacer may be used to separate the temperature sensor from the device's housing that contacts the object. The spacer may include a thermal path from the housing to the temperature sensor, and may be opaque to the light detected by a light detector.

Abstract: One embodiment described herein takes the form of a wearable electronic device, such as a watch, including a housing, a memory and a processor located in the housing, and three or more sensors. Each sensor of the three or more sensors is configured to generate a measurement of a parameter. Each sensor of the three or more sensors is located in a different region in the housing. The processor is configured to execute instructions stored in the memory. In response to execution of the instructions by the processor, the processor is configured to generate an adjusted measurement of the biometric parameter using at least the measurements of the parameter generated by the three or more sensors. The parameter is a temperature, and the biometric parameter is a body temperature of a user.

Abstract: An internal heat-generating component noise correction technique can be used to improve accuracy of temperature sensing. In some examples, a method includes at an electronic device including a first temperature sensor and a first heat-generating component, measuring a first temperature using the first temperature sensor, and in accordance with a determination that one or more criteria are satisfied, compensating the first temperature based on a first estimate of heat generated by the first heat-generating component to generate a second temperature, and estimating a third temperature external to the electronic device using the second temperature.

Abstract: Detecting user contact with one or more electrodes of a physiological signal sensor can be used to ensure physiological signals measured by the physiological signal sensor meet waveform characteristics (e.g., of a clinically accurate physiological signal). In some examples, a mobile and/or wearable device can comprise sensing circuitry, stimulation circuitry, and processing circuitry. The stimulation circuit can drive one or more stimulation signals on one or more electrodes, the resulting signal(s) can be measured (e.g., by the sensing circuitry), and the processing circuitry can determine whether a user is in contact with the electrode(s). Additionally or alternatively, in some examples, mobile and/or wearable device can comprise saturation detection circuitry, and the processing circuitry can determine whether the sensing circuitry is saturated.

Abstract: Detecting user contact with one or more electrodes of a physiological signal sensor can be used to ensure physiological signals measured by the physiological signal sensor meet waveform characteristics (e.g., of a clinically accurate physiological signal). In some examples, a mobile and/or wearable device can comprise sensing circuitry, stimulation circuitry, and processing circuitry. The stimulation circuit can drive one or more stimulation signals on one or more electrodes, the resulting signal(s) can be measured (e.g., by the sensing circuitry), and the processing circuitry can determine whether a user is in contact with the electrode(s). Additionally or alternatively, in some examples, mobile and/or wearable device can comprise saturation detection circuitry, and the processing circuitry can determine whether the sensing circuitry is saturated.

Abstract: An internal heat-generating component noise correction technique can be used to improve accuracy of temperature sensing. In some examples, a method includes at an electronic device including a first temperature sensor and a first heat-generating component, measuring a first temperature using the first temperature sensor, and in accordance with a determination that one or more criteria are satisfied, compensating the first temperature based on a first estimate of heat generated by the first heat-generating component to generate a second temperature, and estimating a third temperature external to the electronic device using the second temperature.

Abstract: Detecting user contact with one or more electrodes of a physiological signal sensor can be used to ensure physiological signals measured by the physiological signal sensor meet waveform characteristics (e.g., of a clinically accurate physiological signal). In some examples, a mobile and/or wearable device can comprise sensing circuitry, stimulation circuitry, and processing circuitry. The stimulation circuit can drive one or more stimulation signals on one or more electrodes, the resulting signal(s) can be measured (e.g., by the sensing circuitry), and the processing circuitry can determine whether a user is in contact with the electrode(s). Additionally or alternatively, in some examples, mobile and/or wearable device can comprise saturation detection circuitry, and the processing circuitry can determine whether the sensing circuitry is saturated.

Abstract: Disclosed herein are electronic devices, including wearable electronic devices, and components and configurations thereof, having one or more temperature sensors separated from the point of contact of the electronic device and an object, such as a user, whose temperature is being measured. In some embodiments, the electronic device includes both a temperature sensor and a light (visible, UV, and/or IR) emitter and sensor. Various embodiments are disclosed by which a temperature sensor may be shielded or separated from a light emitter/detector. A spacer may be used to separate the temperature sensor from the device's housing that contacts the object. The spacer may include a thermal path from the housing to the temperature sensor, and may be opaque to the light detected by a light detector.

Abstract: One embodiment described herein takes the form of a wearable electronic device, such as a watch, including a housing, a memory and a processor located in the housing, and three or more sensors. Each sensor of the three or more sensors is configured to generate a measurement of a parameter. Each sensor of the three or more sensors is located in a different region in the housing. The processor is configured to execute instructions stored in the memory. In response to execution of the instructions by the processor, the processor is configured to generate an adjusted measurement of the biometric parameter using at least the measurements of the parameter generated by the three or more sensors. The parameter is a temperature, and the biometric parameter is a body temperature of a user.

Abstract: Detecting user contact with one or more electrodes of a physiological signal sensor can be used to ensure physiological signals measured by the physiological signal sensor meet waveform characteristics (e.g., of a clinically accurate physiological signal). In some examples, a mobile and/or wearable device can comprise sensing circuitry, stimulation circuitry, and processing circuitry. The stimulation circuit can drive one or more stimulation signals on one or more electrodes, the resulting signal(s) can be measured (e.g., by the sensing circuitry), and the processing circuitry can determine whether a user is in contact with the electrode(s). Additionally or alternatively, in some examples, mobile and/or wearable device can comprise saturation detection circuitry, and the processing circuitry can determine whether the sensing circuitry is saturated.

Abstract: Detecting user contact with one or more electrodes of a physiological signal sensor can be used to ensure physiological signals measured by the physiological signal sensor meet waveform characteristics (e.g., of a clinically accurate physiological signal). In some examples, a mobile and/or wearable device can comprise sensing circuitry, stimulation circuitry, and processing circuitry. The stimulation circuit can drive one or more stimulation signals on one or more electrodes, the resulting signal(s) can be measured (e.g., by the sensing circuitry), and the processing circuitry can determine whether a user is in contact with the electrode(s). Additionally or alternatively, in some examples, mobile and/or wearable device can comprise saturation detection circuitry, and the processing circuitry can determine whether the sensing circuitry is saturated.

Abstract: Detecting user contact with one or more electrodes of a physiological signal sensor can be used to ensure physiological signals measured by the physiological signal sensor meet waveform characteristics (e.g., of a clinically accurate physiological signal). In some examples, a mobile and/or wearable device can comprise sensing circuitry, stimulation circuitry, and processing circuitry. The stimulation circuit can drive one or more stimulation signals on one or more electrodes, the resulting signal(s) can be measured (e.g., by the sensing circuitry), and the processing circuitry can determine whether a user is in contact with the electrode(s). Additionally or alternatively, in some examples, mobile and/or wearable device can comprise saturation detection circuitry, and the processing circuitry can determine whether the sensing circuitry is saturated.

Abstract: A circuit (10) includes a circuit input (12), a circuit output (16) and a one or more delay elements (22) positioned between the circuit input (12) and the circuit output (16). The delay elements (22) each include a differential input pair (234), a latch stage (236) and a delay controller (244A1, 244A2, 244B1, 244B2). The delay controller (244A1, 244A2, 244B1, 244B2) selectively apportions current between the differential input pair (234) and the latch stage (236) to achieve a desired delay value for the circuit (10). The circuit (10) can also include a feedback loop (18) that calibrates a DC offset of the delay elements (22). The delay elements (22) can include two or more sets of resistive loads (238A, 238B) and a rate controller (241). The rate controller (241) controls an on/off state of the resistive loads (238A, 238B) to selectively switch between full resistance and half resistance.

Abstract: An equalization system (18) that reduces inter-symbol interference in an input signal (220) includes a variable gain amplifier (430), and one or more peaking amplifiers (432) that are connected in series to the variable gain amplifier (430). The variable gain amplifier (430) receives the input signal (220) and scales the input signal (220) while each peaking amplifier (432) can be selectively controlled to selectively adjust a peaking gain (326) and a peaking corner frequency (328). Additionally, the equalization system (18) can include a PTAT bias generator (434) that provides a PTAT bias current to one or more of the peaking amplifiers (432) to maintain a transconductance of one or more of the peaking amplifiers (432) substantially constant as temperature changes. With this design, the equalization system (18) provides programmable and stabilized equalization gain, has a tunable peaking corner frequency, and superior common mode rejection.

Abstract: A circuit (10) includes a circuit input (12), a circuit output (16) and a one or more delay elements (22) positioned between the circuit input (12) and the circuit output (16). The delay elements (22) each include a differential input pair (234), a latch stage (236) and a delay controller (244A1, 244A2, 244B1, 244B2). The delay controller (244A1, 244A2, 244B1, 244B2) selectively apportions current between the differential input pair (234) and the latch stage (236) to achieve a desired delay value for the circuit (10). The circuit (10) can also include a feedback loop (18) that calibrates a DC offset of the delay elements (22). The delay elements (22) can include two or more sets of resistive loads (238A, 238B) and a rate controller (241). The rate controller (241) controls an on/off state of the resistive loads (238A, 238B) to selectively switch between full resistance and half resistance.

Abstract: A method and apparatus for varying an output clock signal frequency to match the frequency of an output data signal frequency for a SERDES circuit while maintaining a constant input clock frequency is shown. According to this method and apparatus, a PMA rate signal may control the frequency of the output clock while a datastrobe signal may be used to control the frequency of the data signal. Accordingly, the apparatus and methods may be used to produce an output data signal and a clock signal having frequencies that may be lower than the frequency of the input clock signal.

Abstract: An equalization system (18) that reduces inter-symbol interference in an input signal (220) includes a variable gain amplifier (430), and one or more peaking amplifiers (432) that are connected in series to the variable gain amplifier (430). The variable gain amplifier (430) receives the input signal (220) and scales the input signal (220) while each peaking amplifier (432) can be selectively controlled to selectively adjust a peaking gain (326) and a peaking corner frequency (328). Additionally, the equalization system (18) can include a PTAT bias generator (434) that provides a PTAT bias current to one or more of the peaking amplifiers (432) to maintain a transconductance of one or more of the peaking amplifiers (432) substantially constant as temperature changes. With this design, the equalization system (18) provides programmable and stabilized equalization gain, has a tunable peaking corner frequency, and superior common mode rejection.

Abstract: An integrated circuit includes a phase step generator and a clock circuit. The phase step generator generates an input clock signal based on a reference clock and the clock circuit generates an output clock signal based on the input clock signal. Additionally, the clock circuit generates a feedback clock signal based on the output clock signal and locks a phase of the feedback clock signal with a phase of the input clock signal. In response to an assertion of a trigger signal, the phase step generator extends a phase of the input clock signal by inserting a phase step into the reference clock signal. A bandwidth of the clock circuit is determined based on the output clock signal after assertion of the trigger signal.

Abstract: An integrated circuit comparator includes a pair of differential input transistors having gate terminals configured to receive a pair of differential input signals and a comparator output circuit electrically coupled to the pair of differential input transistors. A pair of differential offset compensation transistors are also provided. This pair of differential offset compensation transistors, which is electrically coupled to the pair of differential input transistors, has gate terminals that are configured to receive a pair of unequal dc offset voltages.

Abstract: A Voltage-to-Current converter includes a current mirror having first and second poles, a first transistor coupled between the first pole of the current mirror and a low voltage through a first resistor, a second transistor coupled between the second pole of the current mirror and a low voltage through a second resistor wherein the second resistor is substantially identical with the first resistor, and wherein the output current is dependent on resistance of the first resistor, the input voltage signal applied to the gate of the first transistor, and a reference voltage signal applied to the gate of the second resistor.