Hello,
I would like to ask if it is possible, to use the RTC RV-3028-C7 as the external crystal for low-power clock source as in the below design:
Currently, we have on our custom board an nRF52832 module, to which we connect a crystal and the two capacitors as the design recommended above, to achieve lower power consumption, and also we have configured XTAL as Softdevice closk source.
The application uses Softdevice s132, app timers, and through I2C, we take timestamps from RV-3028-C7 (RTC on our board), so even if the MCU powers down, the RTC will keep time.
My question is, since the specific RTC apart from i2C pins, it has the CLKOUT pin which gives square wave of 32.768 kHz, can replace the crystal. Maybe we can use only the RTC on the board, both I2C and CLKOUT pin concurrently (this can be done and confirmed by the datasheet and the manufacturer), in order to save space on the board and remove the crystal. They have also informed me that " CLKOUT = 32.768 kHz has an accuracy of ±5 ppm @ 25 °C, but follows a parabolic curve versus temperature."
Is it acceptable or it must certainly be connected to a crystal and not to an RTC that has an internal crystal oscillator?
I also attach the datasheet of the RV-3028-C7.RTC_RV_3028_C7_Aug2019_Rev_1_1_Datasheet.pdf
Thank you very much in advance.
