Capacitance of a 32Mhz Crystal

RE: Capacitance of a 32Mhz Crystal

mathiaso — Tue, 16 Jul 2024 07:22:16 GMT

No worries. Then I'll close the case.

RE: Capacitance of a 32Mhz Crystal

JK5 — Tue, 16 Jul 2024 06:23:54 GMT

Thank you.
I was looking at the wrong datasheet.

RE: Capacitance of a 32Mhz Crystal

mathiaso — Mon, 15 Jul 2024 14:34:26 GMT

As there is still no open and public documentation for the nRF54 series, I suggest that you contact your local RSM for inquiries regarding this product series.

RE: Capacitance of a 32Mhz Crystal

Search — Mon, 15 Jul 2024 14:13:17 GMT

I have learned that in the nRF53 series, the chip has a bypass capacitor with a certain capacity value, and the designer can simplify the circuit by selecting the crystal oscillator that conforms to the chip parameters. Does this mean that the subsequent design of nordic, such as the 54 series, will also have a bypass capacitor in chips?

RE: Capacitance of a 32Mhz Crystal

mathiaso — Mon, 15 Jul 2024 13:43:29 GMT

Yes, C_L refers to the load capacitance found in the crystal's datasheet and a C1 and C2 of 12 pF is a result of a C_L = 8 pF,
⇒ C1 = C2 = 2*C_L - 4 pF = 2*8 pF - 4 pF = 12 pF.

RE: Capacitance of a 32Mhz Crystal

Search — Mon, 15 Jul 2024 08:54:44 GMT

In the component parameters, the crystal oscillator also has load capacitance. Take PCA10040 as an example, the internal load capacitance of 32Mhz crystal oscillator is 8pF. Do you consider the internal load capacitance of crystal oscillator in your calculation?