Patent ID: 8508396

Claim:
A signal processing device for amplifying an inputted analog signal, and converting the amplified signal to a digital signal for output comprising: an analog circuit unit for processing the analog signal arranged on a substrate; and a digital circuit unit for processing the digital signal arranged on a substrate, wherein the analog circuit unit performs amplification and cuts off a high frequency component with respect to the inputted analog signal, wherein the digital circuit unit performs conversion to a digital signal of a predetermined format and waveform rectification with respect to the signal which is subjected to amplification and whose high frequency component is cut off by the analog circuit unit for output, wherein the digital circuit unit comprises a conversion circuit for rectifying the waveform for output by converting the signal which is subjected to amplification and whose high frequency component is cut off by the analog circuit unit to the digital signal, and wherein the analog circuit unit differentially outputs a signal which is subjected to amplification and whose high frequency component is cut off.