This disclosure relates generally to switching power supplies and, more particularly, to techniques for magnetization balancing with regard to such power supplies.
A common problem a power supply design such as the power supply 100 illustrated by
Accordingly, a need remains for magnetization balancing with particular regard to power supplies.
Embodiments of the disclosed technology generally pertain to techniques for magnetization balancing for switching power supplies.
Implementations of the disclosed technology are generally directed to a balancing technique for switching power supplies.
Adding capacitance (here, capacitor C) across the transformer allows the commutation slew rate to be slowed down/controlled. If the volt-seconds are not balanced, the magnetizing current will typically take on a DC component. This DC component will generally cause the one phase to commutate faster and the other to commutate slower. This will shift the volt-second mismatch toward a balance and stop the DC component from continuing to increase. If the gate drives have slow rise and fall times, the starting volt-second mismatch can be significant due to the variation of MOSFET threshold voltage. The result is generally a large difference between the commutation times.
At 602, the commutation time of the two phases corresponding to a power supply having two MOSFETs is measured. In the example, the gate of a first MOSFET will be referred to as Gate 1 and the gate of a second MOSFET will be referred to as Gate 2.
At 604, the timing (e.g., phase) of the on time (pulse width) of Gate 1 relative to the on time (pulse width) of Gate 2 is adjusted (e.g., incremented) in order to balance the volt-second of the two phases.
At 606, a determination is made as to whether the commutation times match (e.g., whether they are substantially equal to each other). If the commutation times match, the method ends as indicated by 608; if the commutation times do not match (e.g., one is larger than the other), the method returns to 604.
The following discussion is intended to provide a brief, general description of a suitable machine in which embodiments of the disclosed technology can be implemented. As used herein, the term “machine” is intended to broadly encompass a single machine or a system of communicatively coupled machines or devices operating together. Exemplary machines may include computing devices such as personal computers, workstations, servers, portable computers, handheld devices, tablet devices, and the like.
Typically, a machine includes a system bus to which processors, memory such as random access memory (RAM), read-only memory (ROM), and other state-preserving medium, storage devices, a video interface, and input/output interface ports can be attached. The machine may also include embedded controllers such as programmable or non-programmable logic devices or arrays, Application Specific Integrated Circuits (ASICs), embedded computers, smart cards, and the like. The machine may be controlled, at least in part, by input from conventional input devices such as keyboards and mice, as well as by directives received from another machine, interaction with a virtual reality (VR) environment, biometric feedback, or other pertinent input.
The machine may utilize one or more connections to one or more remote machines, such as through a network interface, modem, or other communicative coupling. Machines can be interconnected by way of a physical and/or logical network, such as an intranet, the Internet, local area networks, wide area networks, etc. One having ordinary skill in the art will appreciate that network communication may utilize various wired and/or wireless short range or long range carriers and protocols, including radio frequency (RF), satellite, microwave, Institute of Electrical and Electronics Engineers (IEEE) 545.11, Bluetooth, optical, infrared, cable, laser, etc.
Having described and illustrated the principles of the invention with reference to illustrated embodiments, it will be recognized that the illustrated embodiments may be modified in arrangement and detail without departing from such principles, and may be combined in any desired manner. And although the foregoing discussion has focused on particular embodiments, other configurations are contemplated.
In particular, even though expressions such as “according to an embodiment of the invention” or the like are used herein, these phrases are meant to generally reference embodiment possibilities, and are not intended to limit the invention to particular embodiment configurations. As used herein, these terms may reference the same or different embodiments that are combinable into other embodiments.
Consequently, in view of the wide variety of permutations to the embodiments that are described herein, this detailed description and accompanying material is intended to be illustrative only, and should not be taken as limiting the scope of the invention. What is claimed as the invention, therefore, is all such modifications as may come within the scope and spirit of the following claims and equivalents thereto.