A Fast-Transient Boost Converter With Noise-Reduction Techniques for Wireless Sensor Networks

Abstract

This paper presents a fast-transient boost converter with noise-reduction techniques for wireless sensor networks. The modulator can be directly inputted by 0.8–1.2 V for 1.8 V output. The proposed low electromagnetic interference (EMI) boost converter is based on a fast delta–sigma controller. This paper proposes a fast delta–sigma modulator for a boost converter to solve the EMI problem. The proposed converter complies with Federal Communication Commission class B conducted emission limits, in which the harmonic level must be lower than −48 dB $\mu \text{V}$ for frequency from 0.45 to 30 MHz. The measured results show that the maximum efficiency of the proposed converter is 90%, and the recovery time is 4 $\mu \text{s}$ from heavy to light load and 8 $\mu \text{s}$ from light to heavy load. The chip was fabricated in Taiwan Semiconductor Manufacturing Co., Ltd. 1P6M 0.18- $\mu \text{m}$ complementary metal–oxide–semiconductor process, and the chip area is $\sim 0.85$ mm2. It is designed to operate from 1 to 2 MHz with a 3.3- $\mu \text{H}$ inductor and a 10- $\mu \text{F}$ output capacitor. The proposed converter output spectrum is lower than −70 dBm or −40 dB $\mu \text{V}$ .