| 摘要 |
PROBLEM TO BE SOLVED: To provide a resistance value detecting circuit having a satisfied PSRR(power supply ripple removal ratio) in such a degree that the noise entered from the power supply is appeared on a signal output terminal. SOLUTION: The resistance value detecting circuit is constituted in such a manner that resistors R11, R12 are inserted to the bases of transistors Q11, Q12 for applying currents to a magneto-resistance element RMR1 of a current mirror circuit composed of a constant current source I11, transistors Q11, Q21, Q31, Q41 and Q12, Q22, Q32, Q42, and further, capacitors C11, C12 re connected to the bases, other ends of which are connected to the emitters. By this constitution, potentials between the bases-emitters of the transistors Q11, Q12 are stabilized by the capacitors C11, C12 and the resistors R11, R12, and the change of collector currents is reduced, then the PSRR(Power supply ripple removal ratio) is improved in the degree such that the noise entered from the power supply is appeared on the signal output terminal.
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