Patent ID: 7823455

Claim:
A differential pressure transducer with a filter for suppressing a low dynamic pressure P d in presence of a high static pressure P s , said differential pressure transducer comprising: a semiconductor substrate having a top and a bottom surface; a first piezoresistive sensor positioned on said top surface on a first diaphragm; a second piezoresitive sensor positioned on said top surface on a second diaphragm and adjacent to said first sensor; wherein said semiconductor substrate with first and second piezoresistive sensors is configured to act as a differential pressure transducer; and a filter comprising a semiconductor wafer positioned proximate said bottom surface of said semiconductor substrate and having high frequency attenuation means positioned thereon to enable said semiconductor wafer to receive both said dynamic and static pressure at an input end and to provide only said static pressure at an output end proximate to said bottom surface of said semiconductor substrate to provide an output strictly proportional to said dynamic pressure, whereby when said differential transducer receives said low dynamic pressure and said high static pressure on said top surface of said substrate and receives only said high static pressure on said bottom surface through said filter output, said differential transducer provides an output proportional to only said dynamic pressure due to cancellation of said high static pressure.