Ultra-Low-Voltage and Micro-Power Analog Design for Internet of Things

Designing low power and low voltage analog circuits for IoT systems is challenging. Many applications require analog circuits working with sub 1-V supply voltages and with power consumption in the hundreds of nW range while preserving good performances. The present target is to have analog circuits operating at 0.5-V or less. With that supply voltage it is required to design basic building blocks like operational amplifiers, comparators and voltage reference generators. For each of them, the presentation briefly reviews the state of the art and presents some recently published examples of implemented solutions. The analog-to-digital converter is essential for every modern system. Ensuring very low power while providing a medium-high resolution (914 bit) over a signal bandwidth up to about 1 MHz is a typical goal. For these specifications, SAR converters and sigma-delta modulators are typically used. Techniques and recent circuit implementations capable of satisfying diverse requests are presented. A 10-bit, 200-kS/s, 250- nA ADC operating down to 0.7-V and voltage references operating with supply voltages in the 0.4-0.6-V range will be presented.