ADC Self-Calibration Using Reference Voltages for Gain and Offset Errors

The patent applies preliminary action by performing calibration measurements before actual conversions. The system pre-determines gain and offset correction factors by converting known reference voltages (Vref and Vref/2) to digital codes, calculates the errors, and stores correction factors. These pre-calculated factors are then applied to subsequent conversions to compensate for ADC inaccuracies, thereby improving measurement precision without sacrificing digital processing capability.

The patent implements self-service by enabling the ADC system to automatically calibrate itself without external intervention. The microcontroller executes calibration software that autonomously performs reference voltage conversions, calculates gain and offset errors, determines correction factors, and applies them to subsequent conversions. This self-calibrating capability improves measurement precision while minimizing the need for external calibration equipment or manual adjustment, thereby limiting the increase in device complexity.

The patent applies partial action by performing only the minimum necessary calibration measurements - specifically, converting two reference voltages (Vref and Vref/2) to determine gain and offset errors. This limited set of measurements is sufficient to calculate correction factors without requiring extensive calibration data. By performing only these essential partial measurements rather than comprehensive multi-point calibrations, the system achieves acceptable measurement precision while minimizing the impact on conversion productivity.