Abstract:
An optical sensor module is disclosed. The optical sensor module can include a housing comprising an air cavity. An optical emitter die can be disposed in the air cavity of the housing. A top surface of the optical emitter die can face a first side of the housing, the optical emitter die configured to emit light towards the first side of the housing. An optical sensor die can be disposed in the air cavity of the housing adjacent the optical emitter die. The optical sensor die can be spaced from the optical emitter die by a lateral distance. A top surface of the optical sensor die can face the first side of the housing. There may be no septum between the optical sensor die and the optical emitter die that optically separates the optical sensor die and the optical emitter die.
Abstract:
A duty cycle balance module (DCBM) for use with a switch mode power converter. One possible half-bridge converter embodiment includes a transformer driven to conduct current in first and second directions by first and second signals during and second half-cycles, respectively. A current limiting mechanism adjusts the duty cycles of the first and second signals when a sensed current exceeds a predetermined limit threshold. The DCBM receives signals representative of the duty cycles which would be used if there were no modification by the current limiting mechanism and signals Dact—1 and Dact—2 representative of the duty cycles that are actually used for the first and second signals, and outputs signals Dbl—1 and Dbl—2 which modify signals Dact—1 and Dact—2 as needed to dynamically balance the duty cycles of the first and second signals and thereby reduce flux imbalance in the transformer that might otherwise arise.
Abstract:
A switching regulator or other apparatus or techniques can include load current monitoring to provide a digital representation of an estimated load current. Load current monitoring can be performed by a circuit including a counter circuit, a comparator circuit, and a digitally-controlled source coupled to the counter circuit and configured to adjust a bias condition of a sensing device in response to a count provided by the counter circuit in order to establish a proportional relationship between a current conducted by the sensing device and a corresponding current conducted by a power switching device. The counter circuit is configured to increment and decrement the count in response to information provided by the comparator output and the count is generally indicative of the estimated load current, such as an average load current.
Abstract:
A method for detecting a preamble in a received radio signal includes demodulating the radio signal based on a carrier derived from a local timing source to provide a digital signal including a sequence of bits oscillating at approximately a modulated data rate. A bit width of each successive bit of the digital signal is determined. If a pair of consecutive bit widths has a combined width within a threshold, the bit pair is indicated as potentially belonging to a preamble. If a threshold number of potential preamble bit pairs in a sequence of bit pairs within a given window is detected, the sequence of bit pairs is indicated as potentially belonging to a preamble. A measure of bit widths of at least some bits within a sequence of preamble bit pairs can be provided and a frequency of the local timing source can be adjusted according to the measure.
Abstract:
A calibration system for an analog-to-digital converter (ADC) an internal ADC that receives an analog input and converts the analog input to digital multi-bit data. The calibration system also includes a reference shuffling circuit that shuffles reference values of comparators of the internal ADC. Further, the calibration system includes a calibration circuit that calibrates the comparators of the internal ADC. The calibration system includes a digital block that measures an amplitude based on the digital multi-bit data. Additionally, the calibration system includes calibration logic that controls the calibration circuit based on an output of the digital block.
Abstract:
In certain applications, differential amplifiers with infinite common mode rejection ratios are desirable. However, resistance mismatches due to imperfections in the manufacturing create finite common mode rejection ratio in differential amplifiers degrading their performance. Disclosed are apparatus and method for improving the common mode rejection ratio of practical differential amplifiers.
Abstract:
Aspects of this disclosure relate to compensating for a relatively large offset in a signal generated by a sensor, such as a pressure sensor and/or a resistive bridge based sensor. Such offset compensation can include applying an offset correction signal generated by a configurable voltage reference, such as a voltage mode digital-to-analog converter (DAC), to an input of an amplifier included in an instrumentation amplifier to compensate for the offset of the signal generated by the sensor.
Abstract:
The respiration rate of a patient may be measured by sensing respiration motion using two MEMS devices, and by processing a respiration signal produced by processing the outputs of the two MEMS devices. Some embodiments dispose two accelerometers around a patient's abdomen and determine respiratory motion from the difference between the outputs of the two accelerometers. Other embodiments dispose two non-identical accelerometers at substantially the same location on the patient's body, such that each of the accelerometers is exposed to the same respiratory motion, and determine respiratory motion from the difference between the outputs of the two accelerometers.
Abstract:
A micro-isolator is described. The micro-isolator may include a first isolator element, a second isolator element, and a first dielectric material separating the first isolator element from the second isolator element. A second dielectric material may completely or partly encapsulate the second isolator element, or may be present at outer corners of the second isolator element. The second dielectric material may have a larger bandgap than the first dielectric material, and its configuration may reduce electrostatic charge injection into the first dielectric material. The micro-isolator may be formed using microfabrication techniques.
Abstract:
Various examples are directed to systems and methods for managing a sensor. A measurement system may receive, from a host device, a first register map describing a first configuration of a measurement system. The first configuration may be associated with a first sensor. The measurement system may compare the first register map to an error rule set indicating inconsistent register map arrangements. After comparing the first register map to the error rule set, the measurement system may configure a switch matrix of the measurement system to sample the first sensor according to the first configuration of the measurement system. The measurement system may receive a plurality of samples from a first sensor and generate first digital measurement data based at least in part on the plurality of samples.