Sensor and Method for Measuring a Variable Affecting a Capacitive Component
AssigneeValtion Teknillinen Tutkimuskeskus
InventorsHeikki Seppa, Hannu Sipola
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Abstract
The invention relates to a sensor and method for measuring a variable affecting a micro-electromechanical component. The invention is based on creating electronics, which are preferably integrated in a single circuit and which exploit the pull-in point of a micro-electromechanical sensor component such as a direct-current reference, for measuring a variable affecting the sensor, in which case an alternating or a direct-current is arranged over the sensor with the aid of a feedback connection, so that the arrangement operates very close to the pull-in point of the sensor.
Claims26
Sensor for measuring a variable affecting a micro-electromechanical component, characterized in that the sensor comprises
- electronics, which are integrated in a single circuit and
- the sensor is arranged to exploit the pull-in point of a micro-electromechanical sensor component, for measuring a variable affecting the sensor,
- whereby an alternating or a direct-current voltage is arranged over the sensor with the aid of a feedback connection, so that the arrangement operates very close to the pull-in point of the sensor, and
- force-balance measurement is applied, whereby the capacitance of the sensor is kept essentially in constant magnitude.
Method for measuring a variable affecting a micro-electromechanical component, characterized in that in it measurement takes place:
- with help of electronics, which are integrated in a single circuit and
- the sensor exploits the pull-in point of a micro-electromechanical sensor component, for measuring a variable affecting the sensor,
- whereby an alternating or a direct-current voltage is arranged over the sensor with the aid of a feedback connection, so that the arrangement operates very close to the pull-in point of the sensor, and
- force-balance measurement is applied, whereby the capacitance of the sensor is kept essentially in constant magnitude.
Method for measuring a variable affecting a micro-electromechanical component, characterized in that in it measurement takes place:
- using an essentially capacitive micro-electromechanical bridge circuit in a single integrated circuit comprising a micro-electromechanical sensor capacitance (105), which bridge circuit comprises:
- a first (106) and a second bridge capacitance (107) connected in series, and
- along with them a reference capacitance (104) and a sensor capacitance (105) connected in series.
Dependencies are inferred from the claim text.