| 摘要 |
An inductive respiration sensor (10) comprises an inductive transducer (12) and sensing circuitry. The sensing circuitry comprises a transimpedance amplifier, TIA, (14), the sense input (16) of which is operatively connected to the inductive transducer. The TIA is configured to drive a current from its output (20) into the sense input such that the voltage on the sense input follows the voltage applied to the reference input (18) and to cause a voltage on the output indicative of the current. The TIA comprises a first (34) and a second (30) transistor. The collector or drain and the emitter or source of the first transistor are operatively connected between the sense input and the output of the TIA. The emitter or source of the second transistor is connected to the reference input, the collector or drain of the second transistor is connected to the base or gate of the first transistor, and the base or gate of the second transistor is connected to the sense input. |
