Charge pump with current limiting circuit
AssigneeSemtech Corporation
InventorsWilliam E. Rader, David P. Keesor
Life of this patent
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Abstract
A charge pump power supply includes two or more modes of operation. An input protection circuit is connected between an input of the power supply and a voltage source. The input protection circuit regulates the voltage at the input of the power supply, limits current at the input when switching from a weaker mode to a stronger mode, and prevents current reversal when switching from a stronger mode to a weaker mode. In some modes, the power supply continuously provides current to the load, obviating the need for an output capacitor.
Claims11
A multiphase charge pump power supply, comprising
- a) an input connected to a voltage source;
- b) an output providing a regulated output voltage;
- c) at least two capacitors, including a first and a second capacitor;
- d) a switching circuit providing a continuous current at said output comprising a plurality of switches and said at least two capacitors;
- said switching circuit alternating between a first phase and a second phase by selective actuation of said switches;
- e) wherein in said first phase said first capacitor is connected between said input and said output and said second capacitor is connected between said input and said ground;
- and
- f) wherein in a second phase said first and second capacitors are connected in series between said input and said output.
A multimode, multiphase charge pump power supply, comprising
- a) an input circuit, including a current limiting circuit, connected to a voltage source;
- b) an output providing a regulated output voltage;
- c) a switching circuit connected between said input and said output, said switching circuit comprising at least two capacitors and a plurality of switches operative to configure said capacitors in at least two different operating modes, each operating mode comprising a plurality of phases;
- and
- d) a control circuit operative to select the operating mode of said switching circuit, and to predictively enable said current limiting circuit prior to transitioning said switching circuit from a first mode to a second mode so as to limit the current flow into said power supply in said second mode.
Dependencies are inferred from the claim text.