发明名称 |
Semiconductor pressure sensor utilizing capacitance change |
摘要 |
An S/N ratio of an output of a semiconductor pressure sensor is improved, the sensor being of an electrostatic capacitance type pressure sensor for generating an output based upon a ratio between capacitances of a pressure sensitive capacitance element and a reference capacitance element. This semiconductor pressure sensor has: a pressure sensitive capacitance element having an electrostatic capacitance Cs changing with a pressure to be detected; a reference capacitance element having an electrostatic capacitance Cr not changing with the pressure; and a unit for detecting the pressure by outputting a signal corresponding to a ratio between the capacitances Cs and Cr, wherein an initial value Cr<HIL><PDAT>0 </SB><PDAT>of the capacitance Cr and an initial value Cs<HIL><PDAT>0 </SB><PDAT>of the capacitance Cs are defined by 1.2<CR<SB>0</SB><PDAT>/Cs<HIL><PDAT>0</SB><PDAT><1.8. THE CR<SB>0</SB><PDAT>/Cs<HIL><PDAT>0 </SB><PDAT>ratio is adjusted by changing the electrode area or the like of both the elements. In this manner, it is possible to obtain a large pressure gauge output DeltaV, lower an amplification factor of the amplifier, and provide a high precision of the sensor.</PTEXT>
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申请公布号 |
US6631645(B1) |
申请公布日期 |
2003.10.14 |
申请号 |
US20000653165 |
申请日期 |
2000.09.01 |
申请人 |
HITACHI, LTD.;HITACHI CAR ENGINEERING CO., LTD. |
发明人 |
SATOU SHINYA;HANZAWA KEIJI;SHIMADA SATOSHI;MONMA NAOHIRO;MIYAZAKI ATSUSHI |
分类号 |
H01L29/84;G01L9/00;G01L9/12;(IPC1-7):G01L9/12 |
主分类号 |
H01L29/84 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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