US Patent 7495593 Sigma-delta modulator capable of compensating a time delay

A sigma-delta modulator is disclosed. The sigma-delta modulator includes a first integrator, a second integrator, an analog-to-digital converter, a digital-to-analog converter (DAC), and a compensating device. The first integrator receives an input signal for generating a first output signal. The second integrator receives the first output signal for generating a second output signal. The ADC converts the second output signal into a digital modulation signal. The DAC converts the digital modulation signal into an analog feedback signal. The analog feedback signal is transmitted to the first integrator and the second integrator. The compensating device is for compensating the analog feedback signal for a time delay caused by a feedback loop from the ADC through the DAC to the first integrator.