| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a user-friendly differential ΔΣ AD converter which can measure even a negative differential input ΔQ while using such a system as a rectangular wave is input to a capacitor for subtraction. <P>SOLUTION: The differential ΔΣ AD converter comprises a fully differential circuit 1, integration capacitors Ci1, Ci2 provided between the input and output ends of the fully differential circuit 1, a comparator provided at the post-stage of the fully differential circuit 1, a subtraction capacitor Ca connected with the inverting input terminal of the fully differential circuit 1, and a subtraction capacitor Cb connected with the non-inverting input terminal of the fully differential circuit 1. When the ΔQ of a differential input to the fully differential circuit 1 is positive, a rectangular wave is input to the subtraction capacitor Ca without being inverted, and input to the subtraction capacitor Cb while being inverted. When the ΔQ is negative, a rectangular wave is input to the subtraction capacitor Ca while being inverted, and input to the subtraction capacitor Cb without being inverted. <P>COPYRIGHT: (C)2012,JPO&INPIT |
