Analog front-end compensation
AssigneeSensata Technologies, Inc.
InventorsEric Visser, Keith Kawate
Life of this patent
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Abstract
In an embodiment, an apparatus may include a sense element that may measure a property such as, for example, pressure. The sense element may produce an output based on the measured property. Circuitry associated with the sense element may store a voltage that represents the output produced by the sense element. The circuitry may include, for example, a capacitor which may store the voltage. The stored voltage may include one or more parasitic components such as, for example, an offset voltage and/or voltage associated with current leakage. The circuitry may adjust the stored voltage to compensate for the parasitic components. The adjustment may occur over a series of phases of operation of the circuitry.
Claims20
An apparatus comprising:
- a sense element having a reference capacitance (Cref) and a sense capacitance (Csen), the sense element for:
- measuring a property, and
- producing an output based on the measured property;
- an amplifier;
- a feedback capacitor (Cb) connected between an output of the amplifier and an input of the amplifier;
- an input capacitor (Ci) connected between an output of the sense element and the input of the amplifier;
- and
- circuitry for:
- storing a voltage that represents the output produced by the sense element,
- compensating for one or more parasitic components contained in the stored voltage;
- charging Ci to hold a voltage that is based on a leakage current associated with the sense element, and
- injecting the voltage held by Ci into the amplifier to adjust a voltage held by Cb based on the leakage current.
An apparatus comprising:
- a sense element having a reference capacitance (Cref) and a sense capacitance (Csen), the sense element for:
- measuring a property, and
- producing an output based on the measured property;
- an amplifier;
- a feedback capacitor (Cb) connected between an output of the amplifier and an input of the amplifier;
- an input capacitor (Ci) connected between an output of the sense element and the input of the amplifier, Ci holding a voltage associated with a leakage current in the apparatus;
- and
- circuitry for:
- storing a voltage that represents the output produced by the sense element,
- compensating for one or more parasitic components contained in the stored voltage, and
- adjusting a voltage held by Cb based on a leakage current associated with the sense element and an amount of voltage held by Ci.
An apparatus comprising:
- a sense element, having a reference capacitance (Cref) and a sense capacitance (Csen), the sense element for:
- measuring a property, and
- producing an output based on the measured property;
- an amplifier;
- a feedback capacitor (Cb) connected between an output of the amplifier and an input of the amplifier;
- an input capacitor (Ci) connected between an output of the sense element and the input of the amplifier;
- and
- circuitry for:
- storing a voltage that represents the output produced by the sense element,
- compensating for one or more parasitic components contained in the stored voltage,
- charging Ci to hold an offset voltage (V(os)) associated with the amplifier,
- sensing a value of Csen,
- adjusting the voltage held by Ci based on the sensed value, and
- injecting the adjusted voltage held by Ci into the input of the amplifier to adjust a voltage held by Cb.
Dependencies are inferred from the claim text.