Capacitor values nrf52832

[MGdeGroot]

Hi,

in the reference circuit, I see a value of 12pf for C1 and C2. In the murata passive components kit a value of 12pf is also stated, but the part number referenced to a 10pf value and we received a 10pf value.

What is the right value for these capacitors?

Gr's Mark

[Stian Røed Hafskjold]

The capacitor values should be, C1 = C2 = 2*C_L - C_pcb - C_pin, where C_pcb and C_pin adds up to 4 pF for the nRF52, and C_L is the load capacitance of the crystal.

The crystal in the reference design has a load capacitance of: C_L = 8pF. This gives us:

C1 = C2 = 2*8pF - 4pF = 12pF

You need to check the load capacitance of the crystal you are using and find the corresponding C1 and C2 values.

More info:
devzone.nordicsemi.com/.../
infocenter.nordicsemi.com/.../nwp_015.pdf

[MGdeGroot]

Thank you for the explanation! Bit strange it is stated this way in the Murata kit though.