REFERENCE POTENTIAL DIFFERENCE COMPENSATION CIRCUIT

PROBLEM TO BE SOLVED: To sufficiently prevent generation of an error due to the potential difference between both circuit systems without involving an increase in size and cost of a signal processing circuit, and increase of a stray current. SOLUTION: This compensation circuit is provided to a signal processing circuit which is separated into an analog circuit system 1 handling a receive signal of an analog quantity and a digital circuit system 2 handling received data of a digital quantity and compensates an error due to the potential difference ΔV between the reference potentials of both circuit systems 1 and 2 when handling the output signal outputted by the analog circuit system 1 is handled as received data of the digital circuit system 2. In this case, the circuit has a reference potential compensation line 14 which has one end connected to the ground pattern of the reference potential of the digital circuit system 2 so that the signal voltage of the received signal of the analog circuit system 1 is converted into a signal voltage (VSIG-ΔV) of the reference potential of the digital circuit system 2, and a buffer circuit 4 which outputs an output signal, while controlling it into a signal voltage VSIG OUT equal to the signal voltage (VSIG-ΔV).