摘要:
A folding circuit and an analog-to-digital converter wherein a response to small signals is improved, a load on a clock signal can be reduced, and the increase of circuit area can be prevented. The circuit includes a reference voltage generating circuit that generates a plurality of differential voltages as reference voltages, and a plurality of amplification circuits that convert differential voltages between the plurality of reference voltages and an analog input voltage to differential currents, and output these differential currents. The output ends of the amplification circuits are alternately connected. Each of the amplification circuit is configured by a differential amplifier circuit having cascode output transistors (145, 146). A switch (144), which is turned on in synchronization with the control clock, is provided between the both sources of the cascode output transistors (145,146).
摘要:
A switched capacitor sample-and-hold circuit using a source grounded input operational amplifier, wherein a feed forward circuit or a feedback circuit is provided in the operational amplifier and connected to the feedback capacitor of the operational amplifier via switches, an input common voltage or a middle point voltage of outputs is detected, and a difference of the same from a reference voltage is previously charged in the feedback capacitor, thereby suppressing fluctuation of an output operation point at the time of amplification of the operational amplifier.