Research And Design Of A10-bit Successive Approximation ADC

With the rapid development of digital electronic technology, microcontroller (MCU) applications have penetrated into all areas of our lives, from industrial control, aerospace, mobile communications to the almost ubiquitous portable consumer electronics, office automation and automotive electronics. At the same time, SoC (System on Chip) technology continues to evolve and mature, more functional modules integrated on a single chip becoming to an inevitable trend of IC design. Thus, the analog-to-digital converter (ADC) as the bridges of connecting an analog system and digital signal processing system has become a research focus.This paper based on a comparative analysis of the structure of kinds of ADC, on the basis of Wuxi China CSMC0.35um CMOS process, complete design a kind of embedded in16bit MCU of a1MHz clock, a10-bit,90KS/s differential successive approximation ADC with5V power supply. The system uses a new R-C composite structure DAC, through a pair of proportional capacitance realized the reuse of the resistance ladder, effectively reduce the chip area. At the same time, the system uses a new circuit that effectively reducing the differential comparator offset voltage. Completed the circuit and physical layout design of the ADC system, use Spectre simulation tools for the whole system verification in Cadence environment, the dynamic performance of the system parameters drawn by Matlab, its results meet the design requirements.