A continuous-time sigma delta modulator, comprising: a loop filter configured to filter an analog input signal to attenuate quantization errors in a band of interest; a multi-phase oscillator-based quantizer configured to convert an output of the loop filter to an M-bit digital signal, wherein either the input signal is single-ended and the multi-phase oscillator-based quantizer includes a voltage controlled oscillator, VCO, wherein the single-ended input signal filtered through the loop filter is fed into the VCO, wherein the VCO comprises a single ring oscillator including a plurality of inverters cascaded in a ring, and exclusive OR, XOR, gates configured to capture phase differences of two successive phase outputs of the inverters to generate M phases corresponding to the M-bit digital signal, or the input signal is differential and the multi-phase oscillator-based quantizer includes two VCOs arranged in a differential manner, wherein the differential input signal filtered through the loop filter is fed into the two VCOs, respectively, wherein each VCO of the two VCOs comprises a ring oscillator, each ring oscillator including a plurality of inverters cascaded in a ring, and XOR gates configured to capture phase differences of the inverters of the two ring oscillators to generate M phases corresponding to the M-bit digital signal representative of a phase difference between the two VCOs; a splitter configured to split the M-bit digital signal to N bits and M-N bits, wherein the N bits selected from the M bits are evenly distributed over the M bits; a digital-to-analog converter, DAC, configured to generate a feedback signal to be subtracted from the analog input signal based on the N bits; and a digital error correction filter configured to filter the M-N bits and combine the filtered M-N bits with the N bits, wherein the digital error correction filter is configured to adapt a filter function based on a filter function implemented in the loop filter in order to match the digital error correction filter to the filter function of the loop filter. a loop filter configured to filter an analog input signal to attenuate quantization errors in a band of interest; a multi-phase oscillator-based quantizer configured to convert an output of the loop filter to an M-bit digital signal, wherein either the input signal is single-ended and the multi-phase oscillator-based quantizer includes a voltage controlled oscillator, VCO, wherein the single-ended input signal filtered through the loop filter is fed into the VCO, wherein the VCO comprises a single ring oscillator including a plurality of inverters cascaded in a ring, and exclusive OR, XOR, gates configured to capture phase differences of two successive phase outputs of the inverters to generate M phases corresponding to the M-bit digital signal, or the input signal is differential and the multi-phase oscillator-based quantizer includes two VCOs arranged in a differential manner, wherein the differential input signal filtered through the loop filter is fed into the two VCOs, respectively, wherein each VCO of the two VCOs comprises a ring oscillator, each ring oscillator including a plurality of inverters cascaded in a ring, and XOR gates configured to capture phase differences of the inverters of the two ring oscillators to generate M phases corresponding to the M-bit digital signal representative of a phase difference between the two VCOs; a splitter configured to split the M-bit digital signal to N bits and M-N bits, wherein the N bits selected from the M bits are evenly distributed over the M bits; a digital-to-analog converter, DAC, configured to generate a feedback signal to be subtracted from the analog input signal based on the N bits; and a digital error correction filter configured to filter the M-N bits and combine the filtered M-N bits with the N bits, wherein the digital error correction filter is configured to adapt a filter function based on a filter function implemented in the loop filter in order to match the digital error correction filter to the filter function of the loop filter.