A 6b 0.2-to-0.9V Highly Digital Flash ADC with Comparator Redundancy

Microsensor wireless networks and implanted biomedical devices have emerged as exciting new application domains. These applications are highly energy constrained and require flexible, integrated, energy-efficient ADC modules that can ideally operate at the same supply voltage as digital circuits. In many applications, the performance requirements are quite modest (100s kS/s). This paper presents a highly digital ADC architecture compatible with advanced CMOS processes, capable of operating down to a supply voltage of 200mV (i.e., subthreshold regime) and up to 900mV. However, leakage and device variation must be addressed, particularly at low supply voltages.