To provide a Q/V converting circuit equipped with a feedback resistor with high resistance within a small area, a detection device and a gyro sensor and the like therewith, while making it possible to achieve the Q-V converting circuit of low noise by using high resistance.
A detecting circuit 60 includes an amplification circuit 70 amplifying output signal from a vibrator 10. A Q/V converting circuits 72 and 74 prepared in the amplification circuit 70 have a feedback resistor RA1. The feedback resistor RA1 is composed by connecting in series so as to contact an N-type polysilicon layer 210, a non-dope polysilicon layer 200, and a N-type polysilicon layer 220 mutually. As a result of failure to act during manufacturing process of the detection device, generally only minute amount of impurity of P-type is contained in the non-dope polysilicon layer. Thereby, the feedback resistor can be achieved with high resistance.
Takekoshi Noboru
Enami Tomokazu
Yasushi Kuroda