Capacitor value in external crystal oscillator (ECO) circuit of PSoC3/5

Question: How to select the value of capacitors in pi network of external crystal oscillator(ECO) circuit?

 

Answer:

Value of capacitors depends upon the crystal’s load capacitance which is specified in the crystal’s datasheet, pin’s capacitance and PCB trace capacitance. Please refer to AN54439 available at link which explains the value selection in more details.