An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a power converter circuit that is electrically coupled to an electrical power source for receiving alternating current (AC) input power from the electrical source and delivering direct current (DC) output power to an electronic device. The power converter circuit includes a transformer and a switching device coupled to a primary side of the transformer for delivering power from the electrical power source to a primary side of the transformer. A controller is coupled to a voltage sensor and the switching device for receiving the sensed voltage level from the voltage sensor and transmitting a control signal to the switching device to adjust the voltage level of power being delivered to the electronic device.

A DC-DC converter according to one or more embodiments is disclosed that may include: a drive voltage switching circuit of a drive circuit that drives a synchronous rectification MOS transistor. The drive voltage switching circuit may switch a connection so that the drive circuit supplies power from the output voltage to the drive circuit in response to the drive voltage for supplying power to the drive circuit being set to be lower than the output voltage. The drive voltage switching circuit may switch a connection so that the drive circuit supplies power from the drive voltage in response to the drive voltage for supplying power to the drive circuit being set to be higher than the output voltage.

An Uninterruptible Power Supply (UPS) including an input configured to receive input AC power, a backup power input configured to receive backup DC power having a first voltage level from a backup power source, a converter configured to convert the input AC power from the input and the backup DC power from the backup power input into DC power having a second voltage level, the converter including an input selection circuit configured to selectively couple the converter to the input and the backup power input, an inductor, a first converter switch configured to couple a first end of the inductor to a neutral connection, and a second converter switch configured to couple a second end of the inductor to the backup power input via the input selection circuit.

According to various embodiments, a power converter circuit is disclosed. The power converter circuit includes a plurality of voltage splitting units (VSUs) coupled to a plurality of current splitting units (CSUs). The VSUs are connected to each other in series and the CSUs are connected to each other in parallel. The VSUs each have a fixed voltage conversion ratio and are operated at a lower frequency than the CSUs. The CSUs each have an adjustable voltage conversion ratio and are operated at a higher frequency than the VSUs.

A DC-DC converter includes: a first converter including a pass transistor coupled between the first node and a first output, and a body diode connected in parallel to the pass transistor; a sensor coupled between both ends of the pass transistor and which detects a driving current; and a second converter which outputs a second power voltage lower than the first power voltage to a second output. The second converter includes a master inverting converter which outputs the second power voltage independently of the driving current, a slave inverting converter which outputs the second power voltage when the driving current is greater than a predetermined threshold or when the input power voltage is greater than a predetermined boosting voltage limit, and an inverting converter controller which controls operations of the master and slave inverting converters in first and second drive modes based on the driving current and the input power voltage.

A circuit for supplying an error signal to a controller in a boost or SEPIC DC-DC converter includes first, second, and third Zener diodes, first, second, and third resistors, and a MOSFET or BJT switch. The circuit includes, connected to a common voltage input source, a first branch including the switch, the first Zener diode and the first resistor, a second branch including the second Zener diode and the second resistor. The first and second branches are mutually connected to the third resistor, and the third resistor is connected to the controller. A third branch includes the third Zener diode and connections to the base or gate of the switch and ground. Each of the first, second, and third Zener diodes are reverse-biased. The second and third Zener voltages are equal and higher than the first Zener voltage.

A switch-mode active electromagnetic interference (EMI) cancellation circuit comprising a set of low-voltage switching elements and a low-voltage inductor or capacitor located at an input to, or at an output from, a set of high-voltage switching elements employed for the power conversion, wherein a controller is operatively coupled to the second set of switching elements to control switching operations of the second set of switching elements at to apply an opposing matching alternating voltage or current into the inductor or capacitor to cancel that high-frequency ripples flowing through the inductor or capacitor generated from the switching of the set of switching elements of the power converter.

The disclosure describes techniques to implement an isolated power converter circuit topology. The power converter circuit topology may include a level shifter or a low-side capacitor which may be configured to both provide capacitive isolation as well as clamping between power converter circuits arranged in a stacked or interleaved interconnection configuration. By controlling the drive signals to the power converter circuits, each power converter circuit, and the stacked interconnection of power converter circuits, may operate to convert power from one voltage level to a second voltage level in either a forward or reverse direction. In the example of a direct current (DC) battery, the stacked or interleaved interconnection of power converter circuits may be further configured to balance the charge level and amount of power drawn from each cell of a multi-cell DC battery.

ADC-DC converter includes a switch element connected to an input end, a coupling capacitor connected to the switch element at a first node, a first inductor connected to the coupling capacitor at a second node and connected to an output end at a third node, a control circuit configured to control the switch element, a second inductor connected to the first node and a ground, a first diode connected to the second node and the ground, a smoothing capacitor connected to the third node and the ground, a comparator, a second diode connected to the second node and the comparator to supply a power voltage powering the comparator, and an output capacitor connected to the second diode and the ground. The comparator is configured to compare a voltage at the output end with a reference voltage so as to output a comparison result to the control circuit. This DC-DC converter operates stably.

Embodiments of the present invention provide a switching circuit. The circuit comprises: a charging sub-circuit, which has a first input end and an output end; a switching sub-circuit, which has a first end, a second end, and a control end, wherein the control end of the switching sub-circuit is connected to the output end of the charging sub-circuit; and a function sub-circuit, which is connected to the first end or the second end of the switching sub-circuit, and has a first node, wherein an operating voltage of the first node is higher than an input voltage of an input power supply, the switching sub-circuit comprises one or more NMOS switches, and the first input end of the charging sub-circuit is connected to the first node.