Charge pump regulation circuit with overvoltage protection
AssigneeSTMicroelectronics S.r.l.
InventorLaurent Savelli
Life of this patent
Estimating the term…
Abstract
A system of regulation of a charge pump for providing an overvoltage greater by a predetermined amount than a supply voltage, including a constant current source connected between the supply voltage and a control terminal, an N-channel MOS transistor connected between the control terminal and the ground, the gate of which is connected to receive the overvoltage, the transistor being of such dimensions that it conducts all the current provided by the constant current source when the overvoltage is greater than a maximum allowable voltage, and circuitry for limiting the overvoltage when the voltage of the control terminal is close to the ground potential.
Claims5
A system for regulating a charge pump that provides an overvoltage greater, by a predetermined amount, than a supply voltage, including:
- a constant current source connected between the supply voltage and a control terminal;
- an N-channel MOS transistor having a gate that is connected to receive the overvoltage, a source that is connected to ground, and a drain that is connected to the control terminal, the transistor being dimensioned to conduct all the current provided by the constant current source when the overvoltage is greater than a maximum admissible voltage;
- and
- means for limiting the overvoltage when a voltage of the control terminal is close to a ground potential.
Dependencies are inferred from the claim text.