DELTA-SIGMA MODULATOR AND TRANSMITTER HAVING THE SAME

摘要

Disclosed are a delta-sigma modulator and a transmitter including the same. The delta-sigma modulator included in a transmitter includes a first integrator to integrate an input signal and a first feedback signal; a second integrator to integrate an output signal of the first integrator and a second feedback signal; a first comparator and a second comparator to compare an output of the second integrator with a reference signal for outputting a first comparison signal and a second comparison signal, respectively; a first DAC and a second DAC to generate a first signal and a second signal corresponding to the first comparison signal and the second comparison signal, respectively; a delay unit to generate delay signals obtained by delaying the first comparison signal and the second comparison signal by a preset time; and an output DAC to generate an output signal at a multi-voltage level corresponding to the delay signals. Accordingly, the performance and efficiency of the transmitter can be improved. [Reference numerals] (509) First DAC; (511) Second DAC; (515) Delay unit; (517) Output DAC; (519) Offset compensator; (521) Time constant compensator; (523) Differential clock generator; (525) Reference signal generator