Patent ID: 7495593
Filing Date: 2009-02-24
Classification: H03M

Abstract:
1. A sigma-delta modulator comprising: a first integrator, for receiving an input signal and generating a first output signal; a second integrator, for receiving the first output signal and generating a second output signal; an analog-to-digital converter (ADC), for converting the second output signal into a digital modulation signal; a digital-to-analog converter (DAC), for converting the digital modulation signal into an analog feedback signal and transmitting the analog feedback signal to the first integrator and the second integrator; and a compensation device, for generating a compensation signal; wherein the compensation signal is utilized for compensation the analog feedback signal for a time delay caused by a feedback loop from the ADC through the DAC to the first integrator; wherein if the time delay is regarded as Td in the z-domain, the compensation signal comprises Td*Z wherein the compensation device comprises a first compensation unit and a second compensation unit, and the first compensation unit is coupled to the second compensation unit; wherein the first compensation unit is represented by Td in the z-domain.