| 摘要 |
PURPOSE:To obtain the titled converting circuit which is suitably converted into an IC by using a differential amplifier having its reverse phase input connected to a terminal at the other side of a resistance and its forward phase input connected to an input terminal of a current mirror circuit and connecting the output of said amplifir to a base terminal of the current mirror circuit. CONSTITUTION:For an absolute value voltage-to-current converting circuit, an end of a resistance R2 is connected to an input voltage terminal 11 with the other end of the R2 connected in common to the reverse phase input of a differential amplifier A2, the base and the corrector of a NPN transistor TRQ5, the base of a TRQ6 and the emitter of a TRQ7 respectively. The forward phase input of the amplifier A2 is connected to an earth terminal 13, and the output of the A2 is connected to the emitters of the TRQ6 and TRQ6 as well as to the base of the TRQ7 in common. An output terminal 12 is added. When the input voltage VIN is positive, the TRQ5 and Q5 are turned on with the TRQ7 turned off. While the negative feedback is applied to the A2 via the TRQ5. Then an output current IOUT is obtained by a current of VIN/R2. When the VIN in negative, the TRQ7 is turned on with the TRQ5 and Q6 turned off respectively. Thus the current IOUT is obtained in the same way. |
