Circuit employing mosfets and corresponding method
AssigneeSTMicroelectronics Design and Application S.R.O.
InventorSandor PETENYI
Life of this patent
Estimating the term…
Abstract
A MOSFET has a current conduction path between source and drain terminals. A gate terminal of the MOSFET receives an input signal to facilitate current conduction in the current conduction path as a result of a gate-to-source voltage reaching a threshold voltage. A body terminal of the MOSFET is coupled to body voltage control circuitry that is sensitive to the voltage at the gate terminal of the MOSFET. The body voltage control circuitry responds to a reduction in the voltage at the gate terminal of the MOSFET by increasing the body voltage of the MOSFET at the body terminal of the MOSFET. As a result, there is reduction in the threshold voltage. The circuit configuration is applicable to amplifier circuits, comparator circuits and current mirror circuits.
Claims21
A circuit, comprising:
- a first MOSFET having a current conduction path between a first source terminal and a first drain terminal, a first gate terminal configured to receive a first input signal and a first body terminal;
- a second MOSFET having a current conduction path between a second source terminal and a second drain terminal, a second gate terminal configured to receive a second input signal and a second body terminal;
- wherein said first and second MOSFETs are coupled with each other in a differential MOSFET pair and the first and second input signals are a differential input signal;
- body voltage control circuitry, comprising:
- a body voltage control MOSFET having a gate terminal coupled to the first gate terminal of said first MOSFET and configured to receive the first input signal of the differential input signal, and a source-drain current path;
- wherein the source-drain current path couples the first body terminal of the first MOSFET to a reference node.
A circuit, comprising:
- a first MOSFET having a current conduction path between a first source terminal and a first drain terminal, and further including a first gate terminal and a first body terminal;
- a second MOSFET having a current conduction path between a second source terminal and a second drain terminal, and further including a second gate terminal and a second body terminal;
- wherein the first and second MOSFETs are connected in a current mirror arrangement;
- a third MOSFET having a current conduction path between a third source terminal and a third drain terminal, and further including a third gate terminal;
- wherein the third gate terminal is electrically connected to the first drain terminal and the first and second gate terminals;
- and
- wherein the third drain terminal is electrically connected to the first and second body terminals.
A method for performed body voltage control on a circuit that includes at least a first MOSFET having a current conduction path between a first source terminal and a first drain terminal, a first gate terminal configured to receive a first input signal and a first body terminal, and a second MOSFET having a current conduction path between a second source terminal and a second drain terminal, a second gate terminal configured to receive a second input signal and a second body terminal, the method comprising:
- sensing a voltage at the first gate terminal of the first MOSFET;
- and
- in response to a decrease in the sensed voltage at the first gate terminal, increasing a body voltage applied to the first and second body terminals in order to reduce a threshold voltage of at least the first MOSFET.
Dependencies are inferred from the claim text.