Back to results
US 11,979,120 B2Granted
Amplifier circuitry and current sensor having the same
AssigneeAlps Alpine Co., Ltd.
InventorsTakaharu Uekura, Masahiko Ota
Life of this patent
Estimating the term…
Abstract
Amplifying circuitry configured such that when a detection circuit detects an abnormal state in which the level of signals input to a main amplifying circuit exceeds a normal range, a control circuit sets the state of integration of signals in the integration circuit to a default state. When the detection circuit detects the abnormal state and then detects that an operating state returns to a normal state in which the level of signals input to the main amplifying circuit is included in the normal range, the control circuit cancels the setting of the default state in the integration circuit.
Claims11
Amplifier circuitry comprising:
- a main amplifying circuit in which an output is negatively fed back to an input;
- an offset correction circuit that corrects an input offset voltage of the main amplifying circuit;
- a detection circuit that detects an abnormal state in which a level of signals input to the main amplifying circuit exceeds a normal range;
- and
- a control circuit that controls the offset correction circuit,
- wherein in the main amplifying circuit, the input offset voltage is corrected in accordance with correction signals supplied from the offset correction circuit;
- wherein the offset correction circuit includes:
- a chopper amplifier circuit that amplifies an input voltage of the main amplifying circuit,
- a filter circuit that removes a high-frequency component included in output signals of the chopper amplifier circuit, and
- a correction-signal supply circuit that supplies the correction signals corresponding to output signals of the filter circuit to the main amplifying circuit;
- wherein the filter circuit includes an integration circuit provided on a signal path between the chopper amplifier circuit and the correction-signal supply circuit;
- and
- wherein the control circuit:
- sets a state of integration of signals in the integration circuit to a default state, when the detection circuit detects the abnormal state, and
- cancels the setting of the default state in the integration circuit, when the detection circuit detects the abnormal state and then detects that an operating state returns to a normal state in which the level of signals input to the main amplifying circuit is included in the normal range.
12 more elements
A current sensor comprising:
- a magnetic sensor that outputs a detection signal corresponding to a magnetic field due to measurement current;
- a coil that generates a magnetic field in a direction in which the magnetic field due to the measurement current, the magnetic field affecting the magnetic sensor, is canceled out;
- a coil drive circuit that drives the coil in response to the detection signal so that the magnetic field due to the measurement current, the magnetic field affecting the magnetic sensor, and a magnetic field due to current that flows in the coil become equilibrium;
- and
- amplifier circuitry comprising:
- a main amplifying circuit in which an output is negatively fed back to an input;
- an offset correction circuit that corrects an input offset voltage of the main amplifying circuit;
- a detection circuit that detects an abnormal state in which a level of signals input to the main amplifying circuit exceeds a normal range;
- and
- a control circuit that controls the offset correction circuit,
- wherein in the main amplifying circuit, the input offset voltage is corrected in accordance with correction signals supplied from the offset correction circuit;
- wherein the offset correction circuit includes:
- a chopper amplifier circuit that amplifies an input voltage of the main amplifying circuit,
- a filter circuit that removes a high-frequency component included in output signals of the chopper amplifier circuit, and
- a correction-signal supply circuit that supplies the correction signals corresponding to output signals of the filter circuit to the main amplifying circuit;
- wherein the filter circuit includes an integration circuit provided on a signal path between the chopper amplifier circuit and the correction-signal supply circuit;
- and
- wherein the control circuit:
- sets a state of integration of signals in the integration circuit to a default state, when the detection circuit detects the abnormal state, and
- cancels the setting of the default state in the integration circuit, when the detection circuit detects the abnormal state and then detects that an operating state returns to a normal state in which the level of signals input to the main amplifying circuit is included in the normal range.
17 more elements
Dependencies are inferred from the claim text.