An integrated sigma-delta noise-shaped buck converter

An integrated sigma-delta noise-shaped buck converter that uses a discrete-time second order single-bit sigma-delta modulator (DT-SDM2) is presented. The DT-SDM2 buck converter and a compared PWM controller are designed and fabricated on a standard TSMC 0.35 μm 3.3 V CMOS process. The operating frequency of the proposed DT-SDM2 ranges from 400 KHz to 1.2 MHz. Simulation results show that DT-SDM2 has better noise performance than those of PWM and continuous-time SDM2 (CT-SDM2) buck converters.