1.2 Zero-Cross Detector (ZCD)

The Zero-Cross Detector (ZCD) peripheral detects when an alternate voltage crosses through a threshold voltage near to zero volts, i.e. GND potential. The threshold is the zero-crossing reference voltage and is 0.8V above ground for the ZCD peripheral of AVR DA family microcontrollers.

The ZCD peripheral offers more features than the traditional methods used to perform zero-cross detection.

The ZCD peripheral can give the output in the form of a software interrupt on rising edge detection, falling edge detection, and both rising edge and falling edge detection of alternating signal. These features aid users with effective utilization of the ZCD peripheral for detecting zero-crossings on alternating signals.

Additionally, the ZCD peripheral offers the following operational features:

  • ZCD logic output indication
  • ZCD reference voltage (ZCPINV) offset correction
    • Correction by offset current
    • Correction by AC coupling
    • Handling VPEAK variations
  • Event generator to the event system