SWRA640H December 2018 – May 2024 CC1310 , CC1312R , CC1314R10 , CC1350 , CC1352P , CC1352R , CC1354P10 , CC1354R10 , CC2620 , CC2630 , CC2640 , CC2640R2F , CC2640R2F-Q1 , CC2642R , CC2642R-Q1 , CC2650 , CC2652P , CC2652R , CC2652R7 , CC2652RB , CC2652RSIP , CC2674P10 , CC2674R10
The 32.768kHz crystal is optional. The internal low-speed RC oscillator (32kHz) can be used as a reference if the low-power crystal oscillator is not used. The RC oscillator can be calibrated automatically to provide a sleep timer accurate enough for Bluetooth® Low Energy. Using an external crystal has the advantage that it increases sleep clock accuracy and reduces the power consumption for Bluetooth Low Energy (shorter RX windows around connection events). An external crystal is required for time synchronous protocols such as TI 15.4-Stack and wM-Bus.