| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage controlled current source which converts an input signal to a current and supplies it as a differential current source. SOLUTION: A differential voltage generation circuit 110 converts an input voltage Vin to differential voltages V1 and V2, and then inputs them into a first variable current source 132 and a second variable current source 136 respectively. The first variable current source 132 is connected between a first output terminal 104 and a ground voltage, and changes an output current corresponding to the voltage V1. The second variable current source 136 that has the same structure as the first variable current source 132 is connected between a second output terminal 106 and the ground voltage, and changes an output current I4 corresponding to the voltage V2. A first constant current source 122 is connected between a power supply VDD and the first output terminal 104, and outputs a constant current I1. A second constant current source 126 is connected between the power supply VDD and the second output terminal 106, and outputs a constant current I2. A differential current between the current I1 and a current I3 is outputted from the first output terminal 104, and a differential current between the currents I2 and I4 is outputted from the second output terminal 106. COPYRIGHT: (C)2008,JPO&INPIT
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