SNIU028D February 2016 – September 2020 UCD3138 , UCD3138064 , UCD3138064A , UCD3138128 , UCD3138A , UCD3138A64
UCD3138 features two modes when it attempts to use a SAR algorithm to determine an absolute voltage. The first mode is Non-Continuous SAR mode. In this mode, the SAR Control Module restarts the SAR algorithm on each sample trigger from the DPWM module. Upon receipt of a sample trigger from the DPWM modules, a new EADC sample is requested at an AFE gain of 0x0 and the DAC setpoint is reset to midpoint.
The Non-Continuous SAR Mode minimizes power consumption by only running the Analog Front End when a new measurement is needed. The SAR Control Module reruns the entire SAR algorithm on every sample trigger, which may add latency to the acquisition of the absolute voltage value compared to continuous mode.