The conventional second-order Delta-Sigma modulator (DSM) based switching converter (SC) cannot be used for full range (-1 to +1) of input signal. The DSM becomes unstable when the normalized input signal is about 0.4. The output of the second integrator saturates the operational amplifier which is used as comparator in the single-bit quantizer. The three- phase switching converter, based on DSM with hexagonal quantizer, improves the signal to noise ratio as well as the spectral response without improving the range of the input signal. This paper proposes three-phase signal dependant DSM based switching converter with vector quantizer. The proposed three-phase SC increases the input signal to full scale and maintains its stability. The SNR and spectral response are better than the conventional DSM based three-phase switching converter with hexagonal quantizer. The overall maximum percentage of difference in phase voltages is 0.4%.