1. Field of the Invention
Embodiments of the present invention generally relate to a method, apparatus and system for a charge pump with a single capacitor and multiple outputs.
2. Description of the Related Art
Existing charge pumps utilize a flying capacitor to charge a rail. If multiple output rails are to be created existing technology would require multiple flying capacitors and separate switches in the circuit to drive those capacitors. This adds complexity to the circuit and extra components to the system.
Therefore, there is a need for an improved multiple output rails circuit without the multiple flying capacitors.
Embodiments of the present invention relate to a circuit with a single capacitor and multiple outputs. The circuit reuses the same flying capacitor to charge multiple rails by timing the charging cycle sequentially, where the one rail is charged and then the charge pump switches to deliver power to the second rail.
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
The proposed solution reuses the same flying capacitor to charge multiple rails by timing the charging cycle sequentially. As a result, the one rail is charged and then the charge pump switches to deliver power to the second rail.
The circuit in
Moreover, this circuit design uses less external components and less internal switches. As a result, this circuit will have less external components, particularly only one flying capacitor required for the charging and less internal switches than would be necessary for the same number of outputs.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application claims priority from U.S. Provisional Patent Application No. 61/949,371 filed on Mar. 7, 2014, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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61949371 | Mar 2014 | US |