Charge pump circuit and methods of operation thereof
AssigneeWolfson Microelectronics plc
InventorDouglas James Wallace MacFarlane
Life of this patent
Estimating the term…
Abstract
A method of generating a voltage supply (Vout+, Vout−) from a single input supply (+VDD), comprising connecting at least one flying capacitor (Cf) to at least one reservoir capacitor (CR1, CR2) and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor the method including changing from an existing one of said modes to enter a new one of said modes during operation, and operating in at least one transitional mode for a period prior to entering fully said new mode.
Claims30
A method of generating a voltage supply from a single input supply, comprising
- connecting at least one flying capacitor to at least one reservoir capacitor and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor;
- changing from an existing one of said modes to enter a new one of said modes during operation;
- operating in at least one transitional mode for a period prior to entering fully said new mode;
- and
- connecting a current restricting element between the flying capacitor and the voltage supply during said transitional mode for a transition between modes in which the voltage on said reservoir capacitor is higher in the mode being entered than in the existing mode, said current restricting element comprising a constant current source.
A method of generating a voltage supply from a single input supply, comprising
- connecting at least one flying capacitor to at least one reservoir capacitor and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor;
- changing from an existing one of said modes to enter a new one of said modes during operation;
- operating in at least one transitional mode for a period prior to entering fully said new mode, wherein said transitional mode comprises cycles in which the connection of the flying capacitor to said voltage supply is restricted compared with the mode being entered;
- and
- modifying the operation in said transitional mode when the voltage on the reservoir capacitor in the mode being entered is lower than in the existing mode to prevent connection of the flying capacitor across the voltage supply,
- wherein at least two reservoir capacitors are used to carry respective output voltages of nominally equal magnitude and, when operating during said transitional mode, connecting said flying capacitor to said two reservoir capacitors alternately so as to maintain equality while their voltages reduce to the level of the mode being entered.
A method of generating a voltage supply from a single input supply, comprising
- connecting at least one flying capacitor to at least one reservoir capacitor and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor;
- changing from an existing one of said modes to enter a new one of said modes during operation;
- operating in at least one transitional mode for a period prior to entering fully said new mode, wherein said transitional mode comprises cycles in which the connection of the flying capacitor to said voltage supply is restricted compared with the mode being entered;
- and
- modifying the operation in said transitional mode when the voltage on the reservoir capacitor in the mode being entered is lower than in the existing mode to prevent connection of the flying capacitor across the voltage supply,
- wherein operation in the mode being entered comprises repeating cycles of three phases, and operation in the mode being entered in differs from operation in the transition mode in only one of said phases.
A method of generating a voltage supply from a single input supply, comprising
- connecting at least one flying capacitor to at least one reservoir capacitor and to the input supply in repeated cycles so as to generate a voltage on said reservoir capacitor, the cycles differing between at least two modes so that each mode generates a different voltage on said reservoir capacitor;
- changing from an existing one of said modes to enter a new one of said modes during operation;
- operating in at least one transitional mode for a period prior to entering fully said new mode, wherein said transitional mode comprises cycles in which the connection of the flying capacitor to said voltage supply is restricted compared with the mode being entered;
- and
- modifying the operation in said transitional mode when the voltage on the reservoir capacitor in the mode being entered is lower than in the existing mode to prevent connection of the flying capacitor across the voltage supply,
- wherein the voltages in said reservoir capacitors in the mode being entered are each substantially half the voltage of the input supply and are generated using a single flying capacitor.
A charge pump circuit having terminals adapted for connection to at least one reservoir capacitor and at least one flying capacitor and being operable in at least two modes to connect said flying capacitor in repeated cycles to said reservoir capacitor and to a voltage supply so as to generate a voltage on said reservoir capacitor, the cycles differing between the modes so that each mode generates a different voltage on said reservoir capacitor, the circuit being operable to change from an existing one of said modes to enter a new one of said modes during operation, and to operate in a further, transitional mode for a period prior to entering fully the new mode,
- wherein, for a transition between modes in which the voltage on said reservoir capacitor is higher in the mode being entered than in the existing mode, connection of the flying capacitor to the voltage supply during said transitional mode is via a current restricting element, said current restricting element comprising a constant current source.
A charge pump circuit having terminals adapted for connection to at least one reservoir capacitor and at least one flying capacitor and being operable in at least two modes to connect said flying capacitor in repeated cycles to said reservoir capacitor and to a voltage supply so as to generate a voltage on said reservoir capacitor, the cycles differing between the modes so that each mode generates a different voltage on said reservoir capacitor, the circuit being operable to change from an existing one of said modes to enter a new one of said modes during operation, and to operate in a further, transitional mode for a period prior to entering fully the new mode, wherein said transitional mode comprises cycles in which the connection of the flying capacitor to said voltage supply is restricted compared with the mode being entered,
- wherein the voltage on the reservoir capacitor in the mode being entered is lower than in the existing mode, operation in said transitional mode being modified to prevent connection of the flying capacitor across the voltage supply, and
- wherein the circuit comprises terminals for connection to at least two reservoir capacitors carrying respective output voltages of nominally equal magnitude, operation during said transition mode being adapted to connect said flying capacitor to said two reservoir capacitors alternately so as to maintain their voltages in proportion with one another to reduce to the level of the mode being entered.
A charge pump circuit having terminals adapted for connection to at least one reservoir capacitor and at least one flying capacitor and being operable in at least two modes to connect said flying capacitor in repeated cycles to said reservoir capacitor and to a voltage supply so as to generate a voltage on said reservoir capacitor, the cycles differing between the modes so that each mode generates a different voltage on said reservoir capacitor, the circuit being operable to change from an existing one of said modes to enter a new one of said modes during operation, and to operate in a further, transitional mode for a period prior to entering fully the new mode, wherein said transitional mode comprises cycles in which the connection of the flying capacitor to said voltage supply is restricted compared with the mode being entered,
- wherein the voltage on the reservoir capacitor in the mode being entered is lower than in the existing mode, operation in said transitional mode being modified to prevent connection of the flying capacitor across the voltage supply, and
- wherein operation in the mode being entered comprises repeating cycles of three phases, the circuit in the transition made operating differently from the mode being entered in only one of said phases.
A charge pump circuit having terminals adapted for connection to at least one reservoir capacitor and at least one flying capacitor and being operable in at least two modes to connect said flying capacitor in repeated cycles to said reservoir capacitor and to a voltage supply so as to generate a voltage on said reservoir capacitor, the cycles differing between the modes so that each mode generates a different voltage on said reservoir capacitor, the circuit being operable to change from an existing one of said modes to enter a new one of said modes during operation, and to operate in a further, transitional mode for a period prior to entering fully the new mode, wherein said transitional mode comprises cycles in which the connection of the flying capacitor to said voltage supply is restricted compared with the mode being entered,
- wherein the voltage on the reservoir capacitor in the mode being entered is lower than in the existing mode, operation in said transitional mode being modified to prevent connection of the flying capacitor across the voltage supply, and
- wherein the voltages in said reservoir capacitors in the mode being entered are each substantially half the voltage of the input supply and are generated using a single flying capacitor.
A charge pump circuit having terminals adapted for connection to at least one reservoir capacitor and at least one flying capacitor and being operable in at least two modes to connect said flying capacitor in repeated cycles to said reservoir capacitor and to a voltage supply so as to generate a voltage on said reservoir capacitor, the cycles differing between the modes so that each mode generates a different voltage on said reservoir capacitor, the circuit being operable to change from an existing one of said modes to enter a new one of said modes during operation and to operate in a further, transitional mode for a period prior to entering fully the new mode wherein:
- operation in the mode being entered comprises repeating cycles of phases and the circuit in the transitional mode operates in a repeating cycle comprising two of the same phases as the mode being entered.
Dependencies are inferred from the claim text.