Abstract: A step-counter device detects and counts user steps. The device includes a transducer configured to generate an electrical transduction signal in response to user stepping. An energy-scavenging system is coupled to the transducer to generate a power supply voltage in response to the electrical transduction signal. A processing unit is powered by the power supply voltage. The processing unit is further configured to sense the electrical transduction signal and determine whether a user step has occurred and in response to that determination increment a step counter.

Abstract: An energy-scavenging interface includes first and second switches connected in series between an input and reference, and third and fourth switches connected in series between the input and an output. A control circuit closes the first and second switches and opens the third switch for a first time interval to store charge in a storage element. A scaled copy of a peak value of the charging current is obtained. The control circuit then opens the first switch and closes the third and fourth switches to generate an output signal as long as the value in current of the output signal is higher than the value of said scaled copy of the peak value.

Abstract: An energy-scavenging interface receives an input signal from a transducer and supplies an output signal to a load. A switch is connected between the transducer and a reference node, and a diode is connected between the transducer and the load. A control circuit closes the switch for a time interval to permit energy storage in the transducer. A scale copy of a peak value of stored electric current is obtained. The switch is opened when the time interval elapses and the stored energy exceeds a threshold. The stored energy is then released to supply the load through the diode. The switch remains open as long as the value of current in the output signal exceeds the value of the scaled copy of the peak value.

Abstract: A biasing circuit for an acoustic transducer is provided with: a voltage-booster stage, which supplies, on a biasing terminal, a boosted voltage for biasing a first terminal of the acoustic transducer; and filtering elements, set between the biasing terminal and the acoustic transducer, for filtering disturbances on the boosted voltage. The biasing circuit is further provided with switches, which can be actuated so as to connect the first terminal to the biasing terminal of the voltage-booster stage, directly during a start-up step of the biasing circuit, and through the filtering elements at the end of the start-up step.

Abstract: A biasing circuit for an acoustic transducer is provided with: a voltage-booster stage, which supplies, on a biasing terminal, a boosted voltage for biasing a first terminal of the acoustic transducer; and filtering elements, set between the biasing terminal and the acoustic transducer, for filtering disturbances on the boosted voltage. The biasing circuit is further provided with switches, which can be actuated so as to connect the first terminal to the biasing terminal of the voltage-booster stage, directly during a start-up step of the biasing circuit, and through the filtering elements at the end of the start-up step.

Abstract: The input terminals of an energy-scavenging interface are connectable to a transducer including a storage element, and output terminals of the interface are connectable to an electrical load. The interface includes a first switch that is closed to pass current and store electrical energy in the storage element for a first time interval. The first time interval is based on at least one of a first delay proportional to a time constant of the transducer and sensed current flowing through the first switch reaching a first threshold. The first switch is thereafter opened so to permit the stored electrical energy to be delivered through a first current-conduction element for a second time interval. The second time interval is based on sensed current flowing through the first current-conduction element reaching a second threshold. The first current-conduction element may comprise a second switch actuate out of phase with the first switch.

Abstract: An energy scavenging interface has an input port receiving an electrical signal from a storage element of a transducer, and an output port supplying an output signal to an electrical load. The interface includes a first switch receiving the input signal; a second switch that supplying the output signal; and control logic configured to close the first switch and open the second switch for a first time interval having at least a first temporal duration and until current through the first switch reaches a threshold. A scaled copy of a peak value of current through the first switch is obtained during the first time interval. The control logic is further operable to open the first switch and close the second switch to supply current to the electrical load as long as the current of the output signal remains greater than the value of said scaled copy of the peak value.

Abstract: A transducer converts energy coming from an energy source into an electrical signal for storage as electrical energy on a first storage element. A switch is selectively actuated to pass electrical energy from the first storage element to a second storage element. The selective actuation of the switch is driven by sensing electrical energy stored in the second storage element. The switch is closed when electrical energy in the second storage element is sensed to fall below a first threshold. The switch is opened when electrical energy in the second storage element is sensed to rise above a second threshold.

Abstract: A DC-DC converter independently supplies electrical loads. The converter includes a charge switch and a discharge switch connected between an input supply and a reference. An inductor has a first terminal connected between the charge switch and the discharge switch and a second terminal. Coupling switches are provided between the inductor second terminal and the electrical loads. An adaptive-control circuit acquires, during supply of each electrical load, a signal indicating the voltage value across the inductor and generates a first time interval as a function of the signal indicating the voltage value detected. Each electrical load is supplied during the first time interval, and completely discharged during a second time interval subsequent to the first time interval.

Abstract: A rectifier circuit includes a first, second, third and fourth parasitic diodes electrically connected to form a full-wave diode-bridge rectifier. A first switch and a second switch are connected in parallel, respectively, to the first and second parasitic diodes, and a third switch and a fourth switch connected in parallel, respectively, to the third and fourth parasitic diodes. A first biasing network is configured to drive in conduction the first and second switches, during turning-on of the rectifier circuit, using a first turning-on signal that is a function of the input signal. A second biasing network is configured to close the third and fourth switches, during turning-on of the rectifier circuit, using a second turning-on signal that is a function of the input signal.

Abstract: A biasing circuit for an acoustic transducer is provided with: a voltage-booster stage, which supplies, on a biasing terminal, a boosted voltage for biasing a first terminal of the acoustic transducer; and filtering elements, set between the biasing terminal and the acoustic transducer, for filtering disturbances on the boosted voltage. The biasing circuit is further provided with switches, which can be actuated so as to connect the first terminal to the biasing terminal of the voltage-booster stage, directly during a start-up step of the biasing circuit, and through the filtering elements at the end of the start-up step.