Patent ID: 8089388

Claim:
A folding analog-to-digital converter comprising: a reference voltage generating unit that generates a plurality of reference voltages; a low power analog pre-processing unit including a plurality of folders, each of which compares a voltage level of an analog input signal with a corresponding reference voltage of the plurality of reference voltages to generate a pair of differential folded outputs; a comparison unit that compares outputs of the low power analog pre-processing unit to output a digital signal; and an encoding unit that converts an output of the comparison unit into a binary code signal, wherein each of the plurality of folders of the low power analog pre-processing unit includes a plurality of folding units, each of which compares the voltage level of the analog input signal with a corresponding reference voltage of the plurality of reference voltages, wherein the plurality of folding units are cascade-connected to one another, wherein when one of the plurality of folding units receives an output of a previous folding unit of the one folding unit, a current source of the one folding unit is driven so that a current source of a next folding unit of the one folding unit is driven in an operation mode, wherein when the voltage level of the analog input signal is less than the reference voltage, the current source of the one folding unit is driven so that the current source of the next folding unit is converted into a sleep mode.