16-bit Low-Voltage Low Power SIGMA-DELTA Modulator Design

Deep Submicro CMOS process leads to higher integration and realization of higher performance SOC(system on a chip).On the other hand, digital signal processing technology progressing rapidly is accelerating steps of SOC development. However, low-voltage low-power analog circuits are indispensable to implement high performance SOC in deep Submicro process.Analog-to-digital Converter is an important part of SOC. Delta-Sigma Data converters are widely used in the interfaces of analog circuits and digital circuits nowadays due to its' easy implementation with standard CMOS process and without extra requirement to standard CMOS process. At the same time, comparing with the other analog-to-digital converters, Delta-Sigma Data converters can be carried out easily to meet the demand of low-voltage low-power ,and be easily integrated in SOC as a IP.In this paper, Single-stage 1-bitΣ-Δmodulator principle is elaborated and some other improved topologies are presented. Then, aiming at designing low voltage low power circuits, some analog low-voltage design techniques, which are often used currently, are presented, and their advantages and disadvantages are pointed out. Finally, this paper adopt standard advanced digital deep submicro CMOS process(SMIC90n) to design a design a low-voltage low-power three-order 1-bitΣ-Δmodulator. The power supply of the modulator is 1V and total power dissipation is 420 uW. This low voltage low powerΣ-Δmodulator, which can get same performance as other low voltage low powerΣ-Δmodulator, is designed with several techniques different form the low voltage analog design methods used mostly.