Patent ID: 8624765

Claim:
A sample and hold circuit, comprising: a first switch which is turned on when an input voltage is to be sampled; a first sampling part configured to sample the input voltage input via the first switch when the first switch is turned on; a second sampling part configured to sample a predetermined reference voltage when the first switch is turned off; an adding/subtracting part configured to perform an addition or a subtraction between the input voltage sampled by the first sampling part and the predetermined reference voltage sampled by the second sampling part; and a hold part configured to hold and output a voltage obtained by the addition or the subtraction by the adding/subtracting part, wherein the first and the second sampling parts are a common sampling capacitor which is capable of accumulating an input charge according to the input voltage and a reference charge according to the reference voltage, and the adding/subtracting part includes a second switch which is turned on after the input charge is accumulated in the sampling capacitor, a temporary storage capacitor to which the input charge accumulated in the sampling capacitor is transferred when the second switch is turned on, a third switch which is turned on after the input charge accumulated in the sampling capacitor is transferred to the temporary storage capacitor, and a re-transferring part which returns the input charge, which has been transferred to the temporary storage capacitor, after the reference charge is accumulated in the sampling capacitor when the third switch is turned on, in order to perform the addition or the subtraction of the charge accumulated in the sampling capacitor.