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US 12,618,920 B2Granted
Ratiometric sensor circuit
AssigneeInfineon Technologies AG
InventorEdwin Mario Motz
Life of this patent
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Abstract
The present disclosure relates to a sensor circuit including a control circuit configured to control a constant first signal to a ratiometric second signal using a first amplifier adjustable by an actuating signal, and an adjustable second amplifier for a sensor signal, the gain of which is adjustable by the actuating signal.
Claims23
A sensor circuit, comprising:
- a first voltage divider configured to provide a constant first signal as a first differential signal based on a constant voltage source, the first differential signal comprising a first pair of signals representative of a constant first voltage difference;
- a second voltage divider configured to provide a ratiometric second signal as a second differential signal based on an external supply, the second differential signal comprising a second pair of signals representative of a second voltage difference;
- a control circuit including a first amplifier, the control circuit configured to control a ratio of the constant first signal to the ratiometric second signal using a differential output of the first amplifier, a first gain of the first amplifier being adjustable by an actuating signal that is different from the constant first signal,
- the first amplifier comprising a first Metal Oxide Semiconductor (MOS) differential stage that includes a first Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and a second MOSFET,
- wherein a first current source is coupled to integrated source terminals of the first MOSFET and the second MOSFET of the first MOS differential stage;
- and
- an adjustable second amplifier for amplifying a sensor signal, the adjustable second amplifier including a second MOS differential stage corresponding to the first MOS differential stage, and a second gain of the adjustable second amplifier being adjustable by the actuating signal,
- wherein a second current source is coupled to integrated source terminals of a first MOSFET and a second MOSFET of the second MOS differential stage,
- wherein the control circuit is configured to:
- generate the actuating signal based on the ratio,
- adjust the actuating signal in response to a change in the ratio, and
- control, based on a current value of the actuating signal, the first current source to adjust source currents of the first MOSFET and the second MOSFET of the first MOS differential stage in order to adjust the first gain, and
- control, based on the current value of the actuating signal, the second current source to adjust source currents of the first MOSFET and the second MOSFET of the second MOS differential stage in order to adjust the second gain.
10 more elements
A method for operating a sensor circuit, comprising
- providing, by a first voltage divider, a constant first signal as a first differential signal based on a constant voltage source, the first differential signal comprising a first pair of signals representative of a constant first voltage difference;
- providing, by a second voltage divider, a ratiometric second signal as a second differential signal based on an external supply, the second differential signal comprising a second pair of signals representative of a second voltage difference;
- controlling, by a control circuit, a ratio of the constant first signal to the ratiometric second signal using a differential output of a first amplifier of the control circuit, a first gain of the first amplifier being adjustable by an actuating signal that is different from the constant first signal, the first amplifier comprising a first Metal Oxide Semiconductor (MOS) differential stage that includes a first Metal Oxide Semiconductor Field Effect Transistor (MOSFET) and a second MOSFET, wherein a first current source is coupled to integrated source terminals of the first MOSFET and the second MOSFET of the first MOS differential stage;
- generating, by the control circuit, the actuating signal based on the ratio;
- adjusting, by the control circuit, the actuating signal in response to a change in the ratio;
- adjusting the first gain of the first amplifier by controlling, based on an adjustment to the actuating signal, the first current source to adjust source currents of the first MOSFET and the second MOSFET of the first MOS differential stage;
- and
- adjusting a second gain of an adjustable second amplifier based on the adjustment to the actuating signal, the adjustable second amplifier being configured to amplify a sensor signal, the adjustable second amplifier including a second MOS differential stage corresponding to the first MOS differential stage,
- wherein a second current source is coupled to integrated source terminals of a first MOSFET and a second MOSFET of the second MOS differential stage, and
- wherein adjusting the second gain of the adjustable second amplifier includes controlling, based on the adjustment to the actuating signal, the second current source to adjust source currents of the first MOSFET and the second MOSFET of the second MOS differential stage.
7 more elements
A sensor circuit, comprising:
- a first voltage divider configured to provide a constant first signal as a first differential signal based on a constant voltage, the first differential signal comprising a first pair of signals representative of a constant first voltage difference;
- a second voltage divider configured to provide a ratiometric second signal as a second differential signal based on a supply voltage, the second differential signal comprising a second pair of signals representative of a second voltage difference;
- a first amplifier;
- a control circuit configured to receive the constant first signal, receive the ratiometric second signal that is dependent on the supply voltage, and generate an actuating signal based on a ratio of the constant first signal and the ratiometric second signal, wherein the control circuit is configured to adjust the actuating signal in response to a change in the ratio of the constant first signal and the ratiometric second signal, and wherein the first amplifier has a first gain being adjustable based on the actuating signal;
- an adjustable second amplifier configured to amplify a sensor signal according to a second gain to generate an output signal, the second gain being adjustable based on the actuating signal such that the second gain is dependent on the supply voltage;
- a first current source coupled to the first amplifier, wherein the first current source is configured to adjust currents of the first amplifier based on a current value of the actuating signal in order to adjust the first gain;
- and
- a second current source coupled to the adjustable second amplifier, wherein the second current source is configured to adjust currents of the adjustable second amplifier based on the current value of the actuating signal in order to adjust the second gain.
5 more elements
Dependencies are inferred from the claim text.