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:
A time based boost DC-DC converter generates an output voltage using an inductor. A voltage error between the output voltage and a reference voltage is determined and processed in a) an integral control branch which converts the voltage error into an integral control current signal used to control a current controlled oscillator, and b) a proportional branch which converts the voltage error into a proportional control current signal used to control signal a delay line. Current flowing in the inductor is sensed, attenuated and used to apply adjustment to the integral and proportional control current signals. The output from the current controlled oscillator is passed through the delay line and phase detected in order to generate pulse width modulation (PWM) control signaling driving switch operation in the converter.
Abstract:
A switching converter includes a voltage conversion circuit providing an output voltage from an input voltage and a PWM voltage generated in response to first and second oscillating voltages. The input stage of a transconductor circuit provides an input reference current following a difference between a reference voltage and a voltage dependent on the output voltage and according to a transconductance, and an output stage for providing an output reference current from the input reference current. A phase shifter shifts an oscillating reference voltage according to the output reference current to obtain the first and second oscillating voltages. The transconductance is controlled in response to the input voltage resulting in a change of the input reference current. Compensation for that change is provided by subtracting a variable compensation current from the input reference current, where the variable compensation current is generated in response to the input voltage.
Abstract:
A DC-DC converter includes clock generation circuitry generating first and second clock signals that are out of phase, and a control signal generator generating a switching control signal at an edge of the second clock signal based upon a comparison of an error voltage to a summed voltage. Boost circuitry charges an energy storage component during an on-phase and discharges the energy storage component during an off-phase to thereby generate an output voltage. The on-phase and off-phase are set as a function of the switching control signal. Sum voltage generation circuitry generates a ramp voltage in response to an edge of the first clock signal and generates the summed voltage at an edge of the second clock signal. The sum voltage represents a sum of the ramp voltage and a voltage representative of the current flowing in the energy storage component during the on-phase.
Abstract:
An energy harvesting circuit receives an input voltage from a transducer and uses a single inductor operating in a DC-DC converter charging mode to generate charging current at a first output coupled to an energy storage device where a supply voltage is stored. The energy harvesting circuit further receives the supply voltage from the energy storage device and uses the same single inductor operating in a DC-DC converter regulating mode to generate load current at a second output where a regulated load voltage is provided. The energy harvesting circuit switches between the charging mode and the regulating mode in accordance with a discontinuous mode (DCM) control process.
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 electrical-energy harvesting system envisages a transducer for converting energy from an environmental energy source into a transduced signal, an electrical energy harvesting interface for receiving the transduced signal and for supplying a harvesting signal, and an energy storage element coupled to the electrical energy harvesting interface for receiving the harvesting signal. The electrical-energy harvesting system also includes a voltage converter connected to the electrical energy harvesting interface for generating a regulated voltage. The harvesting interface samples an open-circuit voltage value of the transduced signal, generates an optimized voltage value starting from the open-circuit voltage value, and generates an upper threshold voltage and a lower threshold voltage on the basis of the optimized voltage value. The harvesting interface controls the voltage converter in switching mode so that the harvesting signal has a value between the upper and lower threshold voltages in at least one operating condition.
Abstract:
An energy harvesting interface receives an electrical signal from an inductive transducer and outputs a supply signal. An input branch includes a first switch and a second switch connected in series between a first input terminal and an output terminal, and further a third switch and a fourth switch connected in series between a second input terminal and the output terminal. A first electrical-signal-detecting device coupled across the second switch detects a first threshold value of an electric storage current in the inductor of the transducer. A second electrical-signal-detecting device coupled across the fourth switch detects whether the electric supply current that flows through the fourth switch reaches a second threshold value lower than the first threshold value.
Abstract:
A dual input single output (DISO) regulator, includes a comparator configured to receive a first and second power supply signal and to provide a first compared signal; a first switch configured to couple the first power supply source to an intermediate node, and a second switch configured to couple the second power supply source to the intermediate node; a control logic circuit, coupled to the first comparator, to the first switch, and to the second switch, and configured to receive the compared signal to control the first and the second switch in a first and second operating condition based on the compared signal. The intermediate node being biased by an intermediate power supply signal correlated to the first or second power supply signal. The DISO regulator includes a low-dropout regulator, configured to provide a regulated power supply signal based on the intermediate power supply signal.
Abstract:
A control circuit operates to control a switching stage of an electronic converter. The control circuit includes: first terminals providing drive signals to electronic switches of the switching stage; a second terminal receiving from a feedback circuit a first feedback signal proportional to a converter output voltage; and a third terminal configured to receive from a current sensor a second feedback signal proportional to an inductor current. A driver circuit provides the drive signals as a function of a PWM signal generated by a generator circuit as a function of the first and second feedback signals, a reference voltage and a slope compensation signal. A mode selection signal is generated as a function of a comparison between the input voltage and the output voltage. A feed-forward compensation circuit is configured to source and/or sink a compensation current as a function of a variation in the mode selection signal.