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:
In a DC-DC converter, a duty-cycle control signal is generated in response to comparing the switching stage output voltage and a reference voltage signal. A first circuit compares the duty-cycle control signal and a ramp to produce a PWM signal. A second circuit compares the duty-cycle control signal and a skip threshold to produce a skip control signal which halts switching operation of the switching stage. A count is made of number of periods of the skip control signal during a monitoring time window and the number of periods of a clock signal during a period of the skip control signal is counted. When the counted number of skip control signal periods is within a first range and the counted number of clock signal periods is within a second range, a common detection signal is asserted to trigger varying a value of the skip threshold signal.
Abstract:
A supply node receives supply voltage and an output node provides a regulated output voltage to a load. A switching transistor is coupled between the supply and output nodes. The switching transistor is controlled by a drive signal generated by a control circuit to control switching activity. The control circuit includes circuitry to sense a feedback voltage indicative of the regulated output voltage and a comparator generating a comparison logic signal dependent on a comparison of the feedback voltage to a reference. A logic circuit generates a skip signal in response to the comparison logic signal. A counter generates a termination signal. Signal processing circuitry controls the switching activity by asserting the drive signal as a function of the skip signal and the termination signal.
Abstract:
A Single Input Dual Output converter includes a first switch coupling an input to a first inductor terminal, a second switch coupling a second inductor terminal to ground, a third switch coupling the second inductor terminal to a positive output, and a fourth switch coupling the first inductor terminal to a negative output. During time-shared control, the negative and positive outputs are independently served by conversion cycles. Each conversion cycle includes: a positive phase with a positive charge phase (closing only the first and second switches), followed by an additional phase (closing only the first and third switches for a given time duration), and followed by a positive discharge phase (closing only the third and fourth switches). Each conversion cycle further includes a negative phase with a negative charge phase (closing only the first and second switches) followed by a negative discharge phase (closing only the second and fourth switches).
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.
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:
An auto-tuned ramp generator and a method for generating a sawtooth signal are provided. In the method and apparatus, a sawtooth signal is compared to a first reference voltage and a second reference voltage. In response to determining that the sawtooth signal does not exceed the first reference voltage, the voltage level of the sawtooth signal is increased. In response to determining that the sawtooth signal exceeds the second reference voltage, the voltage level of the sawtooth signal is decreased. The voltage level the sawtooth signal is retained if the sawtooth signal remains between the first and second reference voltages.
Abstract:
A switching amplifier, such as a Class D amplifier, includes a current sensing circuit. The current sensing circuit is formed by replica loop circuits that are selectively coupled to corresponding output inverter stages of the switching amplifier. The replica loop circuits operated to produce respective replica currents of the output currents generated by the output inverter stages. A sensing circuitry is coupled to receive the replica currents from the replica loop circuits and operates to produce an output sensing signal as a function of the respective replica currents.
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.