| 摘要 |
Technique of and apparatus for multiplexing the power and signal leads of an implantable piezoresistive pressure transducer. A semiconductor switching circuit multiplexes the two leads between the transducer element and the electronic processing element. During the charge cycle, the switching circuit connects the power source to the two leads. The power source charges a capacitor located within the resistive bridge of the piezoresistive transducer. A sensing cycle causes the switching circuitry to remove the power source from the two leads, and to switch the two leads to the input circuit of the sensing electronics. Optional steering diodes may be employed in the resistive bridge to minimize heating of two of the resistors caused by charging current. The sensing circuit employs a sample and hold technique so that the sensed output is supplied constantly over time without the interruptions caused by the switching circuit action of charging the capacitor within the resistive bridge.
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