High-Precision Low-Power ∑-△ Modulator Based on AZFA Technology
In order to meet the increasingly stringent requirements for low power consumption of high-precision ∑-△ modulators in practical applications,a discrete ∑-△ modulator based on AZFA tech-nology combining auto zero(self-stabilizing)and dual-channel dynamic op amps is proposed.The fully differential second-order single-bit quantization structure of local feedforward and global feedback is adopted,and the modulator has the advantages of low power consumption,low offset,low noise and good stability.The whole circuit adopts SMICBCD 0.18 μm process,and the working voltage is 5 V.The simu-lation results show that the design has excellent performance in terms of signal-to-noise ratio,effective number of bits,overall power consumption and other related indicators at the oversampling rate(OSR)of 512 and the sampling clock frequency of 163 kHz,which is suitable for the application scenarios of low-speed,high-precision and low-power systems.
∑-△ modulatorAuto zeroDual-channel dynamic op ampAZFA technology
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