SBAS978A June 2019 – May 2020 ADS7028
PRODUCTION DATA.
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The zero-crossing-detect (ZCD) module generates a digital output corresponding to the designated analog input signal crossing a configured threshold. Figure 26 shows the digital output corresponding to the threshold crossings of an analog input. In order to detect the threshold crossings on a particular analog input, configure the 4-bit channel ID in the ZCD_CHID register. The threshold crossing to be detected can be configured in the corresponding HIGH_TH register. The output of the ZCD module can be connected to any digital output by configuring the ZCD_TRIG_EN and GPO_VALUE_ZCD registers.
The ADC conversion result of the selected analog input channel is compared with the digital threshold that then sets the digital output accordingly. Transients near zero crossings can be rejected, as calculated in Equation 3, by configuring the ZCD_BLANKING register.