Calibration may be initiated by holding the CAL pin low for at least t_{CAL_L} clock cycles, then holding it high for at least t_{CAL_H} clock cycles, as defined in Timing Requirements: Calibration. The minimum t_{CAL_L} and t_{CAL_H} input clock cycle sequences are required to ensure that random noise does not cause a calibration to begin when it is not desired. The time taken by the calibration procedure is specified as t_CAL. The CAL pin is active in both ECM and non-ECM. However, in ECM, the CAL pin is logically OR'd with the CAL bit, so both the pin and bit must be set low before executing another calibration with either pin or bit.

TI recommends holding the CAL pin high during normal usage of the ADC12D1620 device to reduce the chance that an SEU causes a calibration cycle.