Is external crystal neccessary at all on 52832

Hi,

1. External HF crystal is mandatory if you want to use the radio peripheral. If you are using BLE, you have to use an external 32 MHz crystal with a frequency tolerance of max 40 ppm. As mentioned in this post:

The external HF clock is critical for data timing and more critical to keep the bluetooth radio on the correct frequency. All the 2.4GHz channels are derived from the 32MHz crystal. So the ppm accuracy of the xtal will be the same ppm accuracy of your carrier in the 2.4GHz band.

2 .

External LF crystal(32 kHz)is not mandatory, but recommend. See this and this post.

Since you are migrating to nRF52832, I recommend to take a look at the General PCB design guidelines for nRF52 series tutorial

Hi,

The run current for the 32.768 kHz crystal oscillator is 0.25 µA, while the run current for the 32.768 kHz RC oscillator is 0.6 µA. Except for this there is no "performance degrade". You save some cost and PCB space by using internal RC, but it uses a bit more power.

Hi,

The run current for the 32.768 kHz crystal oscillator is 0.25 µA, while the run current for the 32.768 kHz RC oscillator is 0.6 µA. Except for this there is no "performance degrade". You save some cost and PCB space by using internal RC, but it uses a bit more power.