Sensor and sigma-delta converter
AssigneeSensirion AG
InventorsMoritz Lechner, Andreas Martin Haeberli
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Abstract
A sensor for determining at least one parameter with a sigma-delta converter (1) comprises switched input capacitors and feedback capacitors (Cf1, Cf2, Crefc1, Crefc2, Creff1, Creff2, Crt1, Crt2, Cr1, Cr2, Ctemp1, Ctemp2, Cs1, Cs2). At least one of the capacitors is designed such that its capacitance depends on the parameter to be determined. In this way, the change of capacitance can be directly determined by means of the sigma-delta converter. Due to a symmetric design of the converter a higher accuracy can be reached.
Claims12
A sensor for determining at least one parameter with a sigma-delta-converter comprising
- Switched capacitors comprising at least two input capacitors and at least one feedback capacitor, wherein at least two of the capacitors is a measuring capacitors designed so that their respective capacity depends on the parameter to be determined;
- and
- two oppositely switched amplifier channels wherein one of said measuring capacitors is arranged in each amplifier channel.
A sensor for determining at least one parameter with a sigma-delta-converter comprising
- Switched capacitors comprising at least two input capacitors and at least one feedback capacitor, wherein at least two of the capacitors are measuring capacitors designed so that their respective capacity depends on the parameter to be determined;
- and
- two oppositely switched amplifier channels wherein one of said measuring capacitors is arranged in each amplifier channel
- wherein at least one of the input capacitors is a compensation capacitor and the compensation capacitor can be connected to a compensation potential via a compensation switch and the measuring capacitor to a sensor potential via a sensor switch, wherein the compensation switch is switched substantially in opposite manner to the sensor switch.
A sensor for determining at least one parameter with a sigma-delta-converter comprising
- Switched capacitors comprising at least two input capacitors and at least one feedback capacitor, wherein at least two of the capacitors are measuring capacitors designed so that their respective capacity depends on the parameter to be determined;
- and
- two oppositely switched amplifier channels wherein one of said measuring capacitors is arranged in each amplifier channel
- wherein at least one of the measuring capacitors consists of at least two parallel sub-capacitors at least one of which can selectively be added by means of control unit.
A sensor for determining at least one parameter with a sigma-delta converter, said sigma-delta converter comprising
- switched capacitors comprising at least two input capacitors and at last one feedback capacitor;
- two oppositely switched amplifier channels;
- and
- at least two measurement capacitors arranged as two of said switched capacitors in each of said amplifier channels, wherein the capacity of each measurement capacitor depends on the parameter to be determined.
Dependencies are inferred from the claim text.