A circuit includes an analog-to-digital converter (ADC) and a hysteresis circuit. The ADC is configured to generate a series of digital codes. The hysteresis circuit is configured to: (a) determine that a first digital code of the series of digital codes represents a change in a same direction as previous digital codes and store the first digital code in the register; and (b) determine that a second digital code of the series of digital codes represents a change in direction from previous digital codes, determine that the second digital code is less than a hysteresis value different than a preceding digital code, and not store the second digital code in the register.