An Ultra-Low Power ADC for Distributed Sensor Networks

A successive approximation ADC targeted for use in distributed sensor networks is presented. The individual nodes in these sensor networks are very energy constrained. Typical use of the individual nodes will include long periods of idle time in a low power standby mode followed by a period of activity that may include sampling of the sensors, computation, and communication. The ADC reported here consumes only 3.1 μW, resulting in 31 pJ/8-bit sample at 1V supply with a maximum sampling rate slightly over 100 kS/s. The standby power consumption at 1 V supply is 41 pW. The μ-power consumption makes this one of the lowest power ADCs ever reported.