Improving the large-signal performance of digital pulse-width modulators effectively increases the maximum power capacity without increasing the power supply. To achieve higher efficiency, a number of features have been combined to produce a seamless transition between high-order noise shaping, which exhibits ultra-low noise, and a first-order loop, which has a theoretical maximum duty cycle of 100%. Variable-order feedback and variable-phase sampling enable the system to achieve high accuracy at duty cycles that range from zero to one. The overall system exhibits THD values of 0.01% at power levels almost twice that of similar closed-loop systems.
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