**2. Most-Suited Analog-to-Digital Converter (ADC) Architectures for Internet of Things (IoT)**

The most suited ADC architectures for IoT applications are described in this section. In spite of being an old-fashioned topology and not directly implemented in IoT applications, ΔM is mentioned because it is the basis of ΔΣM and has inspired some other hybrid architectures, such as SAR-ADC with NS, ΔΔΣM or the proposed digital-ΔM with NS ADCs.

Lastly, a qualitative comparison between them is provided considering complexity, dynamic performance, and energy efficiency.
