A voltage converter circuit includes a capacitor having a first end selectively connected to an input power source through a first input switch and a second end selectively connected to the input power source through a second input switch, and a single inductor configured to generate an output voltage in response to a voltage of a node between the single inductor and the first input switch, selectively connect the input power source through the first input switch at the node, and connect the first end of the capacitor at the node.

Described are circuits and techniques to increase the efficiency of radio-frequency (rf) amplifiers including rf power amplifiers (PAs) through “supply modulation” (also referred to as “drain modulation” or “collector modulation”), in which supply voltages provided to rf amplifiers is adjusted dynamically (“modulated”) over time depending upon the rf signal being synthesized. For the largest efficiency improvements, a supply voltage can be adjusted among discrete voltage levels or continuously on a short time scale. The supply voltages (or voltage levels) provided to an rf amplifier may also be adapted to accommodate longer-term changes in desired rf envelope such as associated with adapting transmitter output strength to minimize errors in data transfer, for rf “traffic” variations.

A voltage converting apparatus includes a comparison circuit, a compensation signal generator, and a voltage converter. The comparison circuit generates a comparison result according to an output voltage, an input voltage, and a compensated feedback signal. The compensation signal generator provides a compensation signal held to be equal to a reference voltage at a first time interval in an enable period in a working cycle and sets the compensation signal to be a ramp signal at a second time interval in the enable period. The compensation signal generator generates the compensated feedback signal according to a feedback signal and the compensation signal. The voltage converter generates a control signal according to the comparison result, performs a voltage converting operation through an inductor according to the control signal, and generates the output voltage. The feedback signal is generated according to a current on the inductor.

A voltage converting apparatus includes a comparison circuit, a compensation signal generator, and a voltage converter. The comparison circuit generates a comparison result according to an output voltage, an input voltage, and a compensated feedback signal. The compensation signal generator provides a compensation signal held to be equal to a reference voltage at a first time interval in an enable period in a working cycle and sets the compensation signal to be a ramp signal at a second time interval in the enable period. The compensation signal generator generates the compensated feedback signal according to a feedback signal and the compensation signal. The voltage converter generates a control signal according to the comparison result, performs a voltage converting operation through an inductor according to the control signal, and generates the output voltage. The feedback signal is generated according to a current on the inductor.

The voltage stress is limited across switches in multi-level flying capacitor step-down dc-dc converters during a start-up sequence by a circuit. In one embodiment, the circuit includes a diode that is adapted to prevent reverse current flow during steady state operation, a pull-down switch and a commutation cell, which includes a start-up capacitor and a flying capacitor.

The voltage stress is limited across switches in multi-level flying capacitor step-down dc-dc converters during a start-up sequence by a circuit. In one embodiment, the circuit includes a diode that is adapted to prevent reverse current flow during steady state operation, a pull-down switch and a commutation cell, which includes a start-up capacitor and a flying capacitor.

A power converter converts a medium-voltage output from a solar module to an appropriate voltage to power a solar tracker system. The power converter includes a voltage divider having at least two legs, a first semiconductor switch subassembly coupled in parallel with a first leg of the voltage divider, and a second semiconductor switch subassembly coupled in parallel with a second leg of the voltage divider. The power converter may be a unidirectional or a bidirectional power converter. In implementations, the signals for driving the semiconductor switches of the first and second semiconductor switch subassemblies may be shifted out of phase from each other. In implementations, if the bus voltages to the semiconductor switches are not balanced, the pulse width of the driving signal of the semiconductor switch supplied with the higher bus voltage is decreased for at least one cycle.

A power converter converts a medium-voltage output from a solar module to an appropriate voltage to power a solar tracker system. The power converter includes a voltage divider having at least two legs, a first semiconductor switch subassembly coupled in parallel with a first leg of the voltage divider, and a second semiconductor switch subassembly coupled in parallel with a second leg of the voltage divider. The power converter may be a unidirectional or a bidirectional power converter. In implementations, the signals for driving the semiconductor switches of the first and second semiconductor switch subassemblies may be shifted out of phase from each other. In implementations, if the bus voltages to the semiconductor switches are not balanced, the pulse width of the driving signal of the semiconductor switch supplied with the higher bus voltage is decreased for at least one cycle.

Systems, apparatuses, and methods are described for power conversion. In some examples, the power conversion may be done by an inverter configured to convert a direct current (DC) input to an alternating current (AC) output. The inverter may include a plurality of capacitors connected at the input of a DC/AC module. The system may include a housing configured to house the inverter. Voltage control circuitry may be configured to increase a voltage at the input of the DC/AC module inside the housing of the inverter.

An apparatus includes a PWM ramp generator coupled between a switching node of a power converter and a first input of a comparator, the PWM ramp generator comprising a first resistor and a first capacitor connected in series between the switching node and the first input of the comparator, and a second resistor and a second capacitor connected in parallel between the first input of the comparator and a feedback node, and a PFM control circuit comprising an error amplifier and a current zero crossing detection comparator, wherein the error amplifier is coupled between a second input of the comparator and a reference node, and the PFM control circuit is configured to generate gate drive signal for the power converter when the power converter is configured to operate in a PFM mode.