The Research And Design Of High Resolution Low Power Multi-bit S-△ Modulator

As the consumer electronics market especially the multi-media application market grows fast, the A/D Converter which is the building bridge between the analog environment and digital processor is getting more and more attentions. It is considered that most of the high resolution Audio Frequency∑-ΔA/D Converters consume comparatively high power (>10mW), and the internal∑-Δmodulator of which consume more than 1mW. This paper analyzes the development of∑-ΔA/D Converter technology and the trend, has put forward the research and design approach of the high performance low power audio application∑-Δmodulator, which achieves 16bit resolution and dissipates power consumption less than 500μW.The power optimization of∑-Δmodulator is influenced by its structure to a large degree, so the choice of the key parameters of system is done after careful comparison and validation, which includes the choice analysis of oversampling, loop order and quantization level. Before the circuit implementationt, the effect of the nonidealities of real circuit on system has been analyzed in detail. Besides, an effective simulation toolbox specific to the nonidealities analysis in the SIMULINK environment was established. And the work of nonidealities analysis has be completely done to guide the circuit design. The implementation of circuit is done in the Cadence environment, some improvements of building blocks has be made for power optimization. With the effort of detail work on system design and nonidealities analysis, the circuit implementation achieves a close performance to the design objective under the low power consumption of about 200μW.