DELTA SIGMA ANALOG-TO-DIGITAL CONVERTER

摘要

PURPOSE: A delta-sigma analog digital converter is provided to obtain a wide operation region by converting a dynamic range through the control of the current which is fed back. CONSTITUTION: A modulator(110) generates an over-sampled PDM(Pulse Density Modulated) signal by converting an analog input current. A post process unit generates digital data corresponding to the analog input current by decreasing a sampling ratio of the generated PDM signal. The post process unit generates a selection signal to control the dynamic range of the modulator. The modulator includes a plurality of current source which generates the current with different sizes. The modulator includes a current supply unit(510) which adds the current generated from the selected current source to the analog input current.