| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an offset voltage correction circuit which can capture the differential output signal of a sensor or the like and remove an offset voltage included there. <P>SOLUTION: After setting the values of the reference voltages V<SB>REF1</SB>, V<SB>REF2</SB>, V<SB>REF3</SB>and V<SB>REF4</SB>of the noninverting input terminals of operational amplifiers OP1 and OP2 corresponding to differential no-signal voltages V<SB>1</SB>and V<SB>2</SB>input to input terminals 11 and 12, a differential voltage for which signal voltagesΔV<SB>1</SB>andΔV<SB>2</SB>are added to the no-signal voltages V<SB>1</SB>and V<SB>2</SB>is input. By utilizing the voltage of the inverting input terminals (virtual grounding points) of first and second operational amplifiers OP1 and OP2 generated corresponding to the respective reference voltages, charges are stored and moved in capacitors C<SB>1</SB>, C<SB>2</SB>, C<SB>3</SB>and C<SB>4</SB>(provided that C<SB>1</SB>=C<SB>2</SB>, C<SB>3</SB>=C<SB>4</SB>) wherein the law of conservation of charge is established, and the signal voltagesΔV<SB>1</SB>andΔV<SB>2</SB>from which the no-signal voltages V<SB>1</SB>and V<SB>2</SB>, that are input offset voltages, are removed are output. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
