ABSTRACT
This chapter shares essential knowledge on analogue-to-digital converter (ADC) and to introduce ADC structures and low-power design techniques that are suitable for biomedical applications. It reviews basic sampling theory and the operational principles of quantizers. The chapter reviews major sources of nonideality (noise and nonlinearity) in ADC and their effects on performance investigates with various performance metrics. It discusses suitable ADC structures for low-power biomedical applications and explains the operational principle of the successive approximation register (SAR) ADC in detail, as it is considered to be the most suitable structure. The chapter introduces advances in low-power design techniques in SAR ADCs. It concludes with notes on performance trends of low-power SAR ADCs. In general, the ADCs are known to be one of the most difficult circuit blocks to design. In order to successfully implement an ADC, designers must understand the performance limitations from the circuit nonidealities. The chapter discusses the non-ideality issues. Analogue circuits contain various noise and nonlinearity sources.
