Abstract: There is provided a method of taking pulse oximetry measurements, the method comprising: providing a calibration pulse-oximeter adapted to estimate one or more first, reference SpO2 values from a first, reference PPG signal measured by the pulse-oximeter on a first, reference area of the human body: and, using the same or a different calibration pulse-oximeter, estimating one or more second SpO2 values from a second PPG signal measured by said same or different calibration pulse-oximeter on a second, target area of the human body. At this point, a calibration parameter or calibration function is calculated on the basis of the one or more first, reference SpO2 values and the second SpO2 values. Then, using a measurement pulse-oximeter, a plurality of third SpO2 values is measured from the second PPG signal on the second, target area of the human body and the resulting values are calibrated using said calibration parameter or function.

Abstract: A half bridge switching power stage includes high/low side switches driven in response to a cycle-by-cycle protected driving signal derived from a PWM signal. Signals indicative of detected over-currents at said high/low side switches are processed to output the cycle-by-cycle protected driving signal, when the signal indicative of the detected over-current indicates, during a time interval within which the high/low side switch is turned on, that current flowing in the turned on high/low side switch crosses a given threshold, as an inverted PWM signal by turning off the turned on high/low side switch, and otherwise outputting said cycle-by-cycle protected driving signal as a not inverted PWM signal. An anomaly detection circuit receives the signals indicative of the over-current and switches off both the high/low side switches when an anomaly is detected in a pattern of over-current events in the signals indicative of the over-current.

Abstract: A switching circuit includes first and second half bridges supplying an electrical load via filter networks. During alternate switching sequences a first transistor pair (high-side in one half bridge and low-side in the other half bridge) is switched to a non-conductive state, and a second transistor pair (high-side in the other half bridge and low-side in the one half bridge) is switched to a conductive state. A current flow line is provided by an inductance, a first switch and a second switch between outputs of the half bridges. In a medium-high power mode, the first and second switches are in the conductive state between switching the first pair of transistors to the non-conductive state and the second pair of transistors to the conductive state. In a low or quiescent power mode, switching the first and second switches to the conductive state is refrained due to application of a longer delay.

Abstract: An embodiment apparatus comprises a switching-type output power stage, a modulator circuit configured for carrying out a pulse-width modulation and converting an electrical input signal into an input signal pulsed between two electrical levels, having a mean value proportional to the amplitude of the input signal, and a circuit arrangement for controlling saturation of an output signal supplied by the switching-type output power stage. The circuit arrangement comprises a pulse-remodulator circuit, between the output of the modulator circuit and the input of the switching-type output power stage, that is configured for supplying, as a driving signal to the switching-type output power stage, a respective modulated signal pulsed between two electrical levels, measuring a pulse width as pulse time interval elapsing between two consecutive pulsed-signal edges of the pulsed input signal, and, if the measurement indicates that the latter is below a given minimum value, remodulating the pulsed input signal.

Abstract: An embodiment apparatus comprises a switching-type output power stage, a modulator circuit configured for carrying out a pulse-width modulation and converting an electrical input signal into an input signal pulsed between two electrical levels, having a mean value proportional to the amplitude of the input signal, and a circuit arrangement for controlling saturation of an output signal supplied by the switching-type output power stage. The circuit arrangement comprises a pulse-remodulator circuit, between the output of the modulator circuit and the input of the switching-type output power stage, that is configured for supplying, as a driving signal to the switching-type output power stage, a respective modulated signal pulsed between two electrical levels, measuring a pulse width as pulse time interval elapsing between two consecutive pulsed-signal edges of the pulsed input signal, and, if the measurement indicates that the latter is below a given minimum value, remodulating the pulsed input signal.

Abstract: An embodiment apparatus comprises a switching-type output power stage, a modulator circuit configured for carrying out a pulse-width modulation and converting an electrical input signal into an input signal pulsed between two electrical levels, having a mean value proportional to the amplitude of the input signal, and a circuit arrangement for controlling saturation of an output signal supplied by the switching-type output power stage. The circuit arrangement comprises a pulse-remodulator circuit, between the output of the modulator circuit and the input of the switching-type output power stage, that is configured for supplying, as a driving signal to the switching-type output power stage, a respective modulated signal pulsed between two electrical levels, measuring a pulse width as pulse time interval elapsing between two consecutive pulsed-signal edges of the pulsed input signal, and, if the measurement indicates that the latter is below a given minimum value, remodulating the pulsed input signal.

Abstract: An embodiment pulse-width modulation (PWM) modulator circuit comprises a first half-bridge stage having a first output node and a second half-bridge stage having a second output node. The first output node and the second output node are configured to have an electrical load coupled therebetween to apply thereto a PWM-modulated output signal. The circuit comprises a differential stage having input nodes configured to receive an input signal applied between the input nodes and produce a differential control signal for the first half-bridge stage and the second half-bridge stage. A current comparator is arranged intermediate the differential stage and the first and second half-bridge stages. The current comparator is configured to produce a PWM-modulated drive signal to drive the half-bridge stages as a function of the input signal applied between the input nodes in the differential stage.

Abstract: An embodiment apparatus comprises a switching-type output power stage, a modulator circuit configured for carrying out a pulse-width modulation and converting an electrical input signal into an input signal pulsed between two electrical levels, having a mean value proportional to the amplitude of the input signal, and a circuit arrangement for controlling saturation of an output signal supplied by the switching-type output power stage. The circuit arrangement comprises a pulse-remodulator circuit, between the output of the modulator circuit and the input of the switching-type output power stage, that is configured for supplying, as a driving signal to the switching-type output power stage, a respective modulated signal pulsed between two electrical levels, measuring a pulse width as pulse time interval elapsing between two consecutive pulsed-signal edges of the pulsed input signal, and, if the measurement indicates that the latter is below a given minimum value, remodulating the pulsed input signal.

Abstract: An embodiment pulse-width modulation (PWM) modulator circuit comprises a first half-bridge stage having a first output node and a second half-bridge stage having a second output node. The first output node and the second output node are configured to have an electrical load coupled therebetween to apply thereto a PWM-modulated output signal. The circuit comprises a differential stage having input nodes configured to receive an input signal applied between the input nodes and produce a differential control signal for the first half-bridge stage and the second half-bridge stage. A current comparator is arranged intermediate the differential stage and the first and second half-bridge stages. The current comparator is configured to produce a PWM-modulated drive signal to drive the half-bridge stages as a function of the input signal applied between the input nodes in the differential stage.

Abstract: A method of measuring blood oxygenation consists of measuring Sp02 on one or more test subjects using a first, reference pulse oximetry device (100), such as a medical-grade pulse-oximeter of the kind that employs, for example, a finger-tip clip-type probe. This can be done on each patient over relatively short time periods. Then, the Sp02 is monitored on a target subject across a relatively longer time period using a second, wearable pulse oximetry device (10) that can be worn non-intrusively by the target use, for example in the form of a bracelet. The Sp02 measured using the wearable pulse oximetry device (10), can be measured based on calibration measurements performed using the first, reference pulse oximetry device (100). In this way, the measurements produced by the wearable pulse oximetry device (10) are calibrated using a medical-grade pulse-oximeter (100).

Abstract: A method is for reducing pulse skipping from a characteristic affecting a modulating signal input to an integrator of a pulse width modulation (PWM) modulator, together with a square wave carrier signal for generating a triangular waveform of the PWM modulator. The method may include creating a broad synchronous peak at vertexes of the triangular waveform output by the integrator.

Abstract: A diagnostic circuit is used for detecting the load status of an audio amplifier. The audio amplifier includes two output terminals for connection to a speaker. The diagnostic circuit may include a first circuit, which configured to generate a first signal indicating whether a signal provided via the two output terminals comprises an audio signal. A second circuit can be configured to detect a first measurement signal being indicative for the output current provided via the two output terminals, and to compare the first measurement signal with at least one threshold in order to generate a second signal indicating whether the output current has a low current amplitude profile or a high current amplitude profile. A third circuit can be configured to generate a diagnostic signal as a function of the first and the second signal.

Abstract: A diagnostic circuit is used for detecting the load status of an audio amplifier. The audio amplifier includes two output terminals for connection to a speaker. The diagnostic circuit may include a first circuit, which configured to generate a first signal indicating whether a signal provided via the two output terminals comprises an audio signal. A second circuit can be configured to detect a first measurement signal being indicative for the output current provided via the two output terminals, and to compare the first measurement signal with at least one threshold in order to generate a second signal indicating whether the output current has a low current amplitude profile or a high current amplitude profile. A third circuit can be configured to generate a diagnostic signal as a function of the first and the second signal.

Abstract: A method is for reducing pulse skipping from a characteristic affecting a modulating signal input to an integrator of a pulse width modulation (PWM) modulator, together with a square wave carrier signal for generating a triangular waveform of the PWM modulator. The method may include creating a broad synchronous peak at vertexes of the triangular waveform output by the integrator.

Abstract: A diagnostic circuit is used for detecting the load status of an audio amplifier. The audio amplifier includes two output terminals for connection to a speaker. The diagnostic circuit may include a first circuit, which configured to generate a first signal indicating whether a signal provided via the two output terminals comprises an audio signal. A second circuit can be configured to detect a first measurement signal being indicative for the output current provided via the two output terminals, and to compare the first measurement signal with at least one threshold in order to generate a second signal indicating whether the output current has a low current amplitude profile or a high current amplitude profile. A third circuit can be configured to generate a diagnostic signal as a function of the first and the second signal.

Abstract: A method is for reducing pulse skipping from a characteristic affecting a modulating signal input to an integrator of a pulse width modulation (PWM) modulator, together with a square wave carrier signal for generating a triangular waveform of the PWM modulator. The method may include creating a broad synchronous peak at vertexes of the triangular waveform output by the integrator.

Abstract: A circuit includes a final stage that includes an H-bridge comprising first and second half-bridges. A read circuit is configured to read a load current supplied by a class-D audio-amplifier to a load. The read circuit is configured for estimating the load current by reading a current at an output by the first or second half-bridge by measuring a drain-to-source voltage during an ON period of a power transistor of the H-bridge. A sensing circuit is configured to detect a first drain-to-source voltage from a transistor of the first half-bridge and a second drain-to-source voltage from a corresponding transistor of the second half-bridge. The sensing circuit is also configured to compute a difference between the first drain-to-source voltage and the second drain-to-source voltage and to perform an averaging operation on the difference to obtain a sense voltage value to be supplied to an analog-to-digital converter.

Abstract: A switching amplifier includes a first half-bridge PWM modulator, a second half-bridge PWM modulator, and at least one amplifier stage configured to receive input signals. The switching amplifier also includes a PWM control stage configured to control switching of the first PWM modulator and of the second PWM modulator as a function of the input signals, by respective first PWM control signals and second PWM control signals. The amplifier stage and the PWM control stage have a fully differential structure.

Abstract: A method for the diagnosis of the offset of the resolver of an electric motor, comprising acquiring a predetermined offset of a resolver associated with the electric motor; in a first transient, supplying an excitation current to the phases of the electric motor. As a consequence of the excitation current, a current established on the axis d of minimum reluctance and a current established on an axis q in phase quadrature with respect to the axis of minimum reluctance are determined. The correctness of the offset of the resolver is diagnosed if the current established on the axis d in the first transient is higher than the current established on the axis d in the second or third transient, and if the current established on the axis q in the first transient is lower than the current established on the axis q in the second or third transient.

Abstract: A switching amplifier includes a first half-bridge PWM modulator, a second half-bridge PWM modulator, and at least one amplifier stage configured to receive input signals. The switching amplifier also includes a PWM control stage configured to control switching of the first PWM modulator and of the second PWM modulator as a function of the input signals, by respective first PWM control signals and second PWM control signals. The amplifier stage and the PWM control stage have a fully differential structure.