| 摘要 |
PURPOSE:To decrease remarkably power consumption by forming a current source of a magnetoresistance effect head and a current of each amplifier circuit with one circuit's share. CONSTITUTION:The circuit consists of n-set differential amplifier circuits 7, 8, 9 whose power terminals are connected in series between a voltage source 10 and ground and n-set of magnetoresistance effect heads 2, 4, 6 picking up a signal depending on the change in a constant current source 1 and a resistor connected in series with the constant current source, and capacitors 11, 12 are connected between each high voltage and each low voltage terminals from the 2nd amplifier circuit 8 to the n-th amplifier circuit 9. On the other hand, both terminals of the magnetoresistance effect heads 2, 4, 6 are connected to differential input terminals of the amplifier circuits 7, 8, 9 respectively via capacitors 13-17. The unbalance of the current generated in the amplifier circuits 7-9 in accordance with the amplitude of the inputted signal is absorbed by capacitors 11-12 inserted between voltage source terminals of each amplifier circuit, allowing to reduce remarkably the power consumption due to the differential amplifier circuit. |
