Back to results
US 9,470,744 B2Granted
Analysis circuit for field effect transistors having a displaceable gate structure
AssigneeRobert Bosch GmbH
InventorsAlexander Buhmann, Fabian Henrici
Life of this patent
Estimating the term…
Abstract
An analysis circuit for a field effect transistor having a displaceable gate structure, includes a measurement circuit coupled between a supply voltage connection of the analysis circuit and a drain connection of the field effect transistor and configured to output a measurement signal that is dependent on the current strength of a current flowing through the field effect transistor to a measurement connection.
Claims8
An analysis circuit for a field effect transistor having a movable gate structure, comprising:
- a supply voltage terminal;
- a measuring circuit coupled between the supply voltage terminal and a drain terminal of the field effect transistor, the measuring circuit being configured to output a measurement signal at a measurement terminal, said measurement signal being dependent on a current intensity of a current flowing through the field effect transistor;
- and
- an impedance converter circuit having a reference voltage terminal, said impedance converter circuit being coupled between the measuring circuit and the drain terminal of the field effect transistor and being configured to hold the drain terminal of the field effect transistor at a potential of a reference voltage applied to the reference voltage terminal, the impedance converter circuit comprising:
- a source follower transistor, which is coupled between the measuring circuit and the drain terminal of the field effect transistor;
- and
- an operational amplifier having (i) an output terminal, which is coupled to a gate terminal of the source follower transistor, (ii) an inverting input terminal, which is coupled to the drain terminal of the field effect transistor, and (iii) a non-inverting input terminal, which is coupled to the reference voltage terminal.
4 more elements
A micromechanical sensor, comprising:
- a first field effect transistor having (i) a first movable gate structure, (ii) a first source terminal, which is coupled to a reference potential, (iii) a first drain terminal, and (iv) a first gate terminal, to which a first constant gate voltage is applied;
- and
- a first analysis circuit for the first field effect transistor, the first analysis circuit comprising:
- a first supply voltage terminal and a first measuring circuit coupled between the first supply voltage terminal and the first drain terminal of the first field effect transistor, the first measuring circuit being configured to output a first measurement signal at a first measurement terminal, said first measurement signal being dependent on a current intensity of a current flowing through the first field effect transistor;
- and
- an impedance converter circuit having a reference voltage terminal, said impedance converter circuit being coupled between the first measuring circuit and the first drain terminal of the first field effect transistor and being configured to hold the drain terminal of the first field effect transistor at a potential of a reference voltage applied to the reference voltage terminal, the impedance converter circuit comprising:
- a source follower transistor, which is coupled between the measuring circuit and the drain terminal of the field effect transistor;
- and
- an operational amplifier having (i) an output terminal, which is coupled to a gate terminal of the source follower transistor, (ii) an inverting input terminal, which is coupled to the drain terminal of the field effect transistor, and (iii) a non-inverting input terminal, which is coupled to the reference voltage terminal.
6 more elements
Dependencies are inferred from the claim text.