The recommended layout and routing for the crystal oscillator circuit can be found in the Maxim Integrated Products application note 1896, 'Crystal Oscillator Circuits'. It is essential to follow the recommended layout and routing to ensure the oscillator starts reliably and operates within the specified frequency range.
To ensure the RTC maintains accuracy over temperature and aging, it is essential to use a high-quality crystal oscillator with a low ppm error, and to calibrate the RTC during manufacturing. Additionally, the DS1340Z-33/T&R has a built-in temperature compensation circuit that can be enabled to improve accuracy over temperature.
The maximum capacitance value for the crystal oscillator circuit is 20pF. Exceeding this value may prevent the oscillator from starting or affect its reliability.
While it is possible to use a battery with a different chemistry or voltage rating, it is not recommended. The DS1340Z-33/T&R is designed to work with specific battery chemistries and voltage ratings, and using a different battery may affect the device's performance, accuracy, or reliability.
The DS1340Z-33/T&R has a built-in battery switchover circuit that automatically switches to the backup battery during power failure. However, it is essential to ensure that the backup battery is properly connected and has sufficient capacity to maintain the RTC during power failure.
DS1340Z-33/T&R datasheet
by Maxim Integrated Products
