Tapped Winding Flyback Converter for Multiple Output Voltages

Abstract

The invention relates to a tapped winding flyback converter for multiple output voltages. This disclosure relates to power converters capable of providing multiple output voltage levels. With respect to USB-C adapter design, the converter's output may need to be changed between different voltage levels, e.g., a low voltage (such as 5V, 10V), an intermediate voltage (such as 12V, 20V), or a high voltage (such as 20V, 40V)-based on the charging device's request. By using a tapped-winding transformer, the turns-ratio of a flyback transformer may be intelligently selected for high output voltage ranges, thus enabling the duty cycle to be kept the same for the low and intermediate voltage output levels. The flyback converter would then only need to accommodate the intermediate and high output voltages. For high output voltages, a switch may be activated to put the two windings of the transformer in series; for lower output voltages, the switch may be turned off, such that only one winding is used.

Description

[0001] Cross References to Related Applications [0002] This application claims priority to US Provisional Application No. 62 / 235,033, filed September 30, 2015, which is hereby incorporated by reference in its entirety. Background technique [0003] The present invention generally relates to flyback converter based power converters capable of providing multiple output voltage levels in an efficient manner. Other embodiments are also described herein. [0004] Alternating current (AC) power is usually supplied from a wall outlet and is sometimes referred to as "line power". Electronic devices often include circuitry that runs on direct current (DC) power. AC power may be converted to DC power using an AC to DC power converter circuit. DC power from such an inverter circuit can be used to power electronic devices. DC power can also be used to charge batteries in electronic devices. [0005] AC to DC power converters often include transformers. A transformer in an AC to DC...

AI Technical Summary

Problems solved by technology

However, the "tap winding" configuration can result in an overly complex circuit design, for example, when two or more voltage output levels are required

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