A switched-capacitor DC/DC converter, a switching-mode power supply, and a control method. The switched-capacitor DC/DC converter includes a controllable switch and n switched capacitor modules, where the n switched capacitor modules are connected in series to form a voltage conversion branch circuit, and the voltage conversion branch circuit is connected to the controllable switch in series. n is an integer greater than or equal to 1. When the DC/DC converter implements different voltage conversion ratios, n may be different values. The converter can implement voltage step-down or voltage step-up, and does not include a transformer inside.

This application discloses a photovoltaic system. The photovoltaic system includes a DC/DC converter, a resonant switched capacitor converter, an inverter, and a controller. An input terminal of the DC/DC converter is connected to a photovoltaic array. A first input terminal of the resonant switched capacitor converter is connected to a positive output terminal of the DC/DC converter, and a second input terminal of the resonant switched capacitor converter is connected to a negative output terminal of the DC/DC converter. A first output terminal of the resonant switched capacitor converter is connected to a neutral wire of the inverter, a second output terminal of the resonant switched capacitor converter is connected to a negative bus of the inverter, and the resonant switched capacitor converter includes at least the following two resonant switched capacitor circuits RSCCs connected in parallel: a first RSCC and a second RSCC.

A period from when switching elements S1, S4 at first diagonal positions in a full-bridge inverter are turned off at the same time to when switching elements S2, S3 at second diagonal positions are turned on at the same time, is defined as T1, and a period from when the switching elements S2, S3 at the second diagonal positions are turned off at the same time to when the switching elements S1, S4 at the first diagonal positions are turned on at the same time, is defined as T2. With a total length of T1 and T2 set to be constant, the lengths of T1 and T2 are controlled to be changed every switching cycle.

A secondary side controller for a flyback converter includes an integrated circuit (IC), which in turn includes: a synchronous rectifier (SR) sense pin coupled to a drain of an SR transistor on a secondary side of the flyback converter; a capacitor having a first side coupled to the SR sense pin, the capacitor to charge or discharge responsive to a voltage sensed at the SR sense pin; a diode-connected transistor coupled between a second side of the capacitor and ground; a first current mirror coupled to the diode-connected transistor and configured to receive, as input current, a reference current from a variable current source; and a peak detect transistor coupled to the diode-connected transistor and to an output of the first current mirror. The peak detect transistor is to output a peak detection signal in response to detecting current from the capacitor drop below the reference current.

A device includes a switch network having a plurality of power switches and coupled to a dc rail with a dc voltage, and a resonant tank coupled to the switch network. The resonant tank has a first coil and a resonant capacitor. Gate drive signals of a group of power switches of the plurality of power switches in the switch network are configured to be turned on with a phase shift against a zero crossing of a current in the resonant tank, and the phase shift is configured to adjust the dc voltage or establish a soft-switching condition for the plurality of power switches in an operation mode.

A switching mode power supply preventing a first switch from being falsely triggered. The switching mode power supply detects a peak of an input signal and starts timing a period of time since the arrival of the peak of the input signal is detected. The first switch starts performing the on and off switching operations when the period of time expires.

A magnetic device includes a winding, and insulators by which the winding is surrounded. Each of the insulators is in contact with the winding. A gap exists between each two adjacent of the insulators in a winding direction of the winding.

Apparatus for power conversion are provided. One apparatus includes a power converter including an input circuit and an output circuit. The power converter is configured to receive power from a source for providing power at a DC source voltage V.sub.S. The power converter is adapted to convert power from the input circuit to the output circuit at a substantially fixed voltage transformation ratio K.sub.DC=V.sub.OUT/V.sub.IN at an output current, wherein V.sub.IN is an input voltage and V.sub.OUT is an output voltage. The input circuit and at least a portion of the output circuit are connected in series across the source, such that an absolute value of the input voltage V.sub.IN applied to the input circuit is approximately equal to the absolute value of the DC source voltage V.sub.S minus a number N times the absolute value of the output voltage V.sub.OUT, where N is at least 1.

System and method via which a switching element is switched in a regulated state of a switching converter at a predetermined stable switching frequency, wherein a switch-on point of the switching element is predetermined by a switching signal generated via a sawtooth signal reaching/exceeding a switch-on threshold value such that the switch-on point of the switching element falls in a valley of an oscillating voltage prevailing at the switched-off switching element, where a prevailing period duration of the switching signal is continuously determined to detect the period duration that is compared with a predetermined reference period duration of a period duration reference unit, a control variable is generated from the comparison and a gap is changed between the sawtooth signal, which is influenced with the valley-identifying signal, and the switch-on threshold value until ascertaining, with reference to the determined prevailing period duration, the stable switching frequency has been reached.

An apparatus includes a first power converter and a second power converter. The first power converter converts an input voltage into a first output voltage; the second power converter converts the first output voltage into a second output voltage that powers a load. The second power converter includes a switched-capacitor converter combined with a magnetic device. The switched-capacitor converter provides capacitive energy transfer; the magnetic device provides magnetic energy transfer. Additionally, the second power converter provides unregulated conversion of the first output voltage into the second output voltage via the capacitive energy transfer and the magnetic energy transfer. To maintain the magnitude of the second output voltage within a desired range or setpoint value, the first power converter regulates a magnitude of the first output voltage based on comparison of a magnitude of the second output voltage with respect to a desired setpoint reference voltage.