Second order loop filter and multi-order delta sigma modulator including the same

摘要

Provided is a second order loop filter (LF). The second order LF includes: an operational amplifier including a first input, a second input receiving a differential input of the first input, and an output; an inverter inverting a signal output from the output of the operational amplifier to output an inverted signal; a first resistor connected to between the first input and a first node; a second resistor connected to between the output of the operational amplifier and the first node; a third resistor connected to between the first input and an input signal; a first capacitor connected to between the second input and the first node; a second capacitor connected to between the output of the operational amplifier and an output of the inverter; and a third capacitor connected to between the output and the first input of the operational amplifier, wherein the second input is connected to a ground voltage.