Method and device for adapting the voltage of a MOS transistor bulk
AssigneesSTMicroelectronics S.r.l., Commissariat a l'Energie Atomique
InventorsOlivier Thomas, Marc Belleville, Vincent Liot, Philippe Flatresse
Life of this patent
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Abstract
A circuit for biasing the bulk of a MOS transistor, including a capacitive element connecting the bulk of the MOS transistor to a source of an voltage.
Claims24
A circuit for biasing the bulk of a MOS transistor, wherein the bulk of the MOS transistor is surrounded by a well providing an electric insulation of the bulk, the circuit comprising a capacitive element connecting the bulk of the MOS transistor to a source adapted to provide a periodic A.C. voltage which alternates between a first value for a first time period and a second value for a second time period shorter than half of the first time period, wherein the MOS transistor, the capacitive element and the source of the A.C. voltage form a charge pump for adjusting a charge quantity of the MOS transistor bulk.
A method for biasing a bulk of a MOS transistor, characterized in that the bulk of the MOS transistor is surrounded by a well providing an electric insulation of the bulk, the method comprising:
- connecting a capacitive element to the MOS transistor bulk and to an A.C. voltage source;
- and
- supplying a periodic voltage to the MOS transistor bulk and the capacitive element, the periodic voltage being delivered by the A.C. voltage source, and the A.C. voltage source alternating between a first value for a first time period and a second value for a second time period shorter than half of the first time period, wherein the MOS transistor, the capacitive element and the A.C. voltage source form a charge pump for adjusting a charge quantity of the MOS transistor bulk.
A circuit, comprising:
- a MOS transistor having an isolated bulk;
- and
- a capacitive element coupled to the isolated bulk and to a power source, the power source configured to supply the capacitive element a first voltage for a first time period and a second voltage for a second time period shorter than half of the first time period, wherein the MOS transistor, the capacitive element and the power source form a charge pump for adjusting a charge quantity of the MOS transistor bulk.
A method for biasing an isolated bulk of a MOS transistor, the method comprising supplying a periodic voltage to the isolated bulk, the periodic voltage having a first value for a first time period and a second value for a second time period shorter than half of the first time period, wherein the periodic voltage is supplied to a capacitive element coupled to the isolated bulk, and wherein the MOS transistor, the capacitive element and the supplied periodic voltage form a charge pump for adjusting a charge quantity of the MOS transistor bulk.
Dependencies are inferred from the claim text.