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US 8,427,851 B2Granted
Charge pump circuit and methods of operation thereof
AssigneeWolfson Microelecttronics plc
InventorJohn P. Lesso
Life of this patent
Estimating the term…
Abstract
A charge pump circuit, and associated method and apparatuses, for providing a split-rail voltage supply, the circuit having a network of switches that is operable in a number of different states and a controller for operating the switches in a sequence of said states so as to generate positive and negative output voltages together spanning a voltage approximately equal to the input voltage and centered on the voltage at the common terminal.
Claims44
A charge pump circuit comprising:
- an input terminal for receiving an input voltage;
- first and second output terminals;
- first and second pairs of flying capacitor terminals for connection to first and second flying capacitors respectively;
- and
- a switch network for interconnecting said input terminal, said first and second pairs of flying capacitor terminals, and said first and second output terminals in a plurality of states to generate either a first positive output voltage and a first negative output voltage that are each substantially equal in magnitude to the magnitude of said input voltage or a second positive output voltage and a second negative output voltage that are each substantially equal in magnitude to half the magnitude of said input voltage, wherein said switch network interconnects said first and second pairs of flying capacitor terminals, such that, in one of the plurality of states, the first and second flying capacitor are connected in parallel while said first and second pairs of flying capacitor terminals are disconnected from said input terminal and said first and second output terminals.
2 more elements
A method of generating a plurality of split-rail voltages comprising:
- interconnecting first and second output voltage terminals with an input voltage terminal and first and second pairs of flying capacitor terminals, which are for connecting to first and second flying capacitors respectively, in a plurality of states to generate either a first positive output voltage and a first negative output voltage that are each substantially equal in magnitude to the magnitude of said input voltage or a second positive output voltage and a second negative output voltage that are each substantially equal in magnitude to half the magnitude of said input voltage, wherein said first and second pairs of flying capacitor terminals are interconnected, such that, in one state of the plurality of states, the first and second flying capacitors are connected in parallel while said first and second pairs of flying capacitor terminals are disconnected from said input voltage terminal and said first and second output voltage terminals.
A charge pump circuit comprising:
- an input terminal;
- first and second output terminals;
- a common terminal;
- first and second flying capacitor terminals for connection to a first flying capacitor;
- third and fourth flying capacitor terminals for connection to a second flying capacitor;
- and
- a switch network for interconnecting said input terminal, said common terminal, said first, second, third, and fourth flying capacitor terminals, and said first and second output terminals, said switch network being operable in a first mode to generate a first positive output voltage and a first negative output voltage that are each substantially equal in magnitude to the magnitude of said input voltage and being further operable in at least a second mode to generate a second positive output voltage and a second negative output voltage that are each substantially equal in magnitude to half the magnitude of said input voltage, said switch network comprising:
- a first switch, which, when closed, electrically connects the first flying capacitor terminal to the third flying capacitor terminal, wherein if the first switch is closed and the other switches of the switch network are open, the first flying capacitor terminal and third flying capacitor terminal are connected to one another and not to any other of said terminals;
- a second switch, which, when closed, connects the second flying capacitor terminal to the third flying capacitor terminal;
- and
- a third switch, which, when closed, connects the second flying capacitor terminal to the fourth flying capacitor terminal, wherein if the third switch is closed and the other switches of the switch network are open, the second flying capacitor terminal and fourth flying capacitor terminal are connected to one another and not to any other of said terminals.
8 more elements
Dependencies are inferred from the claim text.