A signal transfer circuit includes a transmission circuit, a conversion circuit and a sensing output circuit. The transmission circuit outputs a driving signal to a signal line. The conversion circuit receives an input signal that is a single-ended signal transferred through the signal line and converts the input signal to a differential signal including a first output amplified signal and a second output amplified signal. The first output amplified signal swings downwardly from a first output DC level and the second output amplified signal swings upwardly from a second output DC level that is lower than the first output DC level. The sensing output circuit generates an output signal based on the differential signal. The number of the signal lines is reduced without decrease in performance of signal transfer, and sizes of the signal transfer circuit and the device including the signal transfer circuit are reduced.