3.3.2 Clock Circuitry

A crystal oscillator is assembled on the PL460-EK board to obtain a precise and stable system clock reference:
  • A 24 MHz clock signal, Y1, generated for the PLC block. For additional information about VXM7-9043-24M0000000, refer to the VXM7 product web page.
Figure 3-7. 24 MHz Crystal Oscillator

Clext = 2x (CXTAL – CPARA – CPCB)

Clext = 2x (4/18 – 0.6/0.7/0.8 – x)

Clext = 2x (18 – 0.7 – 1) = 33 pF

For additional information about the crystal oscillator, refer to the Crystal Selection Guidelines for PL360, ATPL230, ATPL250, SAM4CP16B and SAM4CP16C Application Note (DS00002716).

For additional information about the frequency deviation measure, refer to the PLC Performance Validation Application Note (DS00004914).