A signal converter capable of stabling converting input signals in an extended operation margin, a radio frequency identification (RFID) tag having the signal converter and a method of driving a RFID tag. The signal converter includes a first signal converter which converts an incoming analog signal into a power signal, a second signal converter which converts the analog signal into a first demodulation signal, a signal amplifier which amplifies the first demodulation signal to output a second demodulation signal such that a value of an externally-supplied reference signal is included in a peak-to-peak range of the second demodulation signal, and a logic signal generator which converts the second demodulation signal into a digital signal in response to the power signal. Because the second demodulation signal has an extended operation margin in converting analog signal into digital signal, stable conversion of the input signals is possible, and rate of recognizing RFID tag is improved.