Sigma delta modulation device capable of switching order of loop filter, and loop filter for sigma delta modulation device

A sigma delta modulation device, the device comprising:

• a loop filter including an operational amplifier, and a circuit including a plurality of capacitors, a plurality of resistors, and a plurality of switches, which are connected to the operational amplifier;
• a quantization part quantizing and outputting a signal that is output from the loop filter;
• a feed-back converter converting a digital signal output from the quantization part into an analog signal;
• a memory configured to store one or more instructions;
• and
• a processor configured to execute the one or more instructions stored in the memory, wherein the instructions, when executed by the processor, cause the processor to control turn on or off of the plurality of switches so as to represent signal transfer characteristics of the loop filter for satisfying a third-order transfer function or a second-order transfer, and to adjust resistor values in an equivalent circuit of the loop filter in order to compensate a notch frequency reduced in the loop filter for satisfying the second-order transfer function.