There are provided a digital signal converter and a method of converting a digital signal. The digital signal converter includes: a signal reception unit analyzing a digital input signal received according to a first form; a signal output unit transmitting a digital output signal according to a second form, different from the first form; and a controller converting the digital input signal received according to the first form into a digital output signal to be transmitted according to the second form, wherein the controller controls a power level of the digital output signal according to power supply methods of the first and second forms. Signal transmission and reception methods according to various interfaces may be provided in a limited form factor by adjusting the standard and coding of a digital signal transmitted and received through different interfaces and as to whether to supply power.