The offset system-calibration command corrects ADC1 system offset error. For this type of calibration, externally short the system inputs before the command. When the SYSOCAL1 command is sent, the ADC averages 16 readings to reduce conversion noise for an accurate calibration. When calibration is complete, the offset calibration result is written to the 24-bit offset calibration register (OFCAL[2:0]). The offset calibration register is disabled in chop mode.