A successive approximation A/D converter includes a sample-hold amplifier
circuit configured to sample and hold an input analog voltage to produce
an internal analog voltage proportional to the input analog voltage with
a voltage gain being smaller than 1, a switched capacitor D/A converter
coupled to the sample-hold amplifier circuit and including a plurality of
capacitors for storing electric charge responsive to the internal analog
voltage, the switched capacitor D/A converter configured to switch
couplings of the capacitors in response to a control signal to produce a
comparison analog voltage responsive to the internal analog voltage and
the control signal, a comparator coupled to the switched capacitor D/A
converter to produce a comparison result signal responsive to the
comparison analog voltage, and a control circuit coupled to the
comparator to supply the control signal responsive to the comparison
result signal to the switched capacitor D/A converter.