Charge pump circuits
AssigneeWolfson Microelectronics plc
InventorsJohn Laurence Pennock, John Bruce Bowlerwell
Life of this patent
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AssigneeWolfson Microelectronics plc
InventorsJohn Laurence Pennock, John Bruce Bowlerwell
Estimating the term…
Charge pump circuits having circuit components such as transistors which may be damaged by voltage transients greater than the normal operating voltage levels of the charge pump circuit, such as may be experienced during powering down. The circuit components to be protected are connected in parallel with a leakage element arranged to have a leakage current that is small enough during normal operation to allow the charge pump to operate effectively but which is large enough, during development of a voltage transient, to prevent excess voltage levels being achieved. The leakage element may have a significant leakage current at a voltage less than the breakdown voltage of the circuit component. Suitable leakage elements are poly diodes.
A charge pump circuit comprising:
A method of protecting a circuit component in a charge pump from voltage levels higher than normal operating voltages comprising the step of arranging a leakage element in parallel with said circuit component.
Dependencies are inferred from the claim text.