| 摘要 |
PURPOSE: A variable resistor circuit is provided to allow the variation of resistance only by control voltage regardless of threshold voltage. CONSTITUTION: The circuit has a current mirror part(10) having PMOS transistors(M5,M6) and sending the same current by power voltage(VDD) to different paths, an NMOS transistor(M10) turned on by a current on one path from the current mirror part(10) and passing a current by the power voltage(VDD), the first and second current control parts(20,30) each receiving the current by the power voltage(VDD) through the NMOS transistor(M10) and input voltage(V1,V2) and then supplying a current corresponding to a difference in received voltages, a resistance control part(40) sending the current flowing through the NMOS transistor(M10) and the current control parts(20,30) to ground, and an NMOS transistor(MR) receiving the input voltage(V1,V2) and acting as a resistor by the current flowing on one path from the current mirror part(10).
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