Pressure transducer with temperature compensation circuit
First Claim
1. A pressure transducer comprising:
- a semiconductor substrate including a thin diaphragm;
a pressure sensor portion including a bridge connection of gage resistors formed on said diaphragm;
a first current source connected to said pressure sensor portion and making up a power supply for driving said pressure sensor portion, said first current source supplying a current equivalent to the sum of a current substantially proportional to the absolute temperature and a current independent of temperature; and
a second current source for sinking the current substantially proportional to the temperature characteristic of said gage resistors from said first current source.
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Accused Products
Abstract
A pressure transducer is disclosed comprising a pressure sensor portion having gage resistors in bridge formed on a thin diaphragm of a semiconductor substrate, and a power supply connected to the pressure sensor portion for driving the pressure sensor. The power supply includes a first current source for supplying a temperature-dependent current equivalent to the sum of a current almost proportional to the absolute temperature and a current independent of temperature, and a second current source for sinking the current almost proportional to the temperature characteristic of the gage resistors from the current of the first current source. A temperature compensation circuit is additionally provided to drive the bridge circuit by the difference between the temperature-dependent current and the current proportional to the temperature characteristic in a constant-current driving mode, and by a voltage proportional to the current difference when the output of the bridge circuit is connected to an amplifier whose gain is dependent on temperature.
46 Citations
5 Claims
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1. A pressure transducer comprising:
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a semiconductor substrate including a thin diaphragm; a pressure sensor portion including a bridge connection of gage resistors formed on said diaphragm; a first current source connected to said pressure sensor portion and making up a power supply for driving said pressure sensor portion, said first current source supplying a current equivalent to the sum of a current substantially proportional to the absolute temperature and a current independent of temperature; and a second current source for sinking the current substantially proportional to the temperature characteristic of said gage resistors from said first current source. - View Dependent Claims (2, 3, 4, 5)
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Specification