DS1678S+T&R datasheet by Maxim Integrated Products

DS1678S+T&R Frequently Asked Questions (FAQs)

• What is the recommended power-up sequence for the DS1678S?
  The recommended power-up sequence is to apply VCC first, followed by VBAT. This ensures that the internal voltage regulator is powered up correctly.
• How do I ensure accurate timekeeping during battery backup?
  To ensure accurate timekeeping during battery backup, the battery voltage should be above 2.5V and the battery-backed registers should be updated before entering battery backup mode.
• What is the maximum capacitance value for the X1 and X2 crystals?
  The maximum capacitance value for the X1 and X2 crystals is 20pF. Exceeding this value may affect the oscillator's performance.
• Can I use the DS1678S with a 32.768kHz crystal oscillator?
  Yes, the DS1678S can be used with a 32.768kHz crystal oscillator. However, the oscillator circuitry should be designed to ensure that the crystal is driven at the correct amplitude and frequency.
• How do I handle the case where the battery is completely drained?
  When the battery is completely drained, the DS1678S will reset and the timekeeping will be lost. To handle this case, the system should be designed to detect the battery drain and take appropriate action, such as resetting the system or initializing the RTC.